WWF_ Intensive homestead food production learning manual_draft 1

1 
WWF Intensive homestead food production 
learning manual: March 2021
Contents 
1Water and soil conservation practices for smallholder farmers.............................................................3
1.1Water harvesting and conservation case study ............................................................................3
1.2Overview of WHC Methods...........................................................................................................6
1.3Catchments ................................................................................................................................. 11
1.4Topography– Aspect and slope................................................................................................. 11
Aspect..........................................................................................................................................11
Slope ...........................................................................................................................................12
2Healthy soils.........................................................................................................................................15
2.1Healthy soil is alive. .....................................................................................................................15
2.2Carbon and Soil Organic Matter - the main building block of life and soil..................................15
2.3Why soil organic matter is so important ......................................................................................16
2.4Turning air into soil ......................................................................................................................20
2.5Characteristics of healthy soil.....................................................................................................21
2.6What is soil? ................................................................................................................................23
2.7Characteristics of soil texture types ............................................................................................23
2.8How to tell your soil texture type................................................................................................. 24
2.9Soil structure ...............................................................................................................................26
2.10Identification of Soil Structure.....................................................................................................27

2 
2.11Soil Degradation..........................................................................................................................28
3Turning runoff into 'run-on'...................................................................................................................30
3.1Soil fertility ...................................................................................................................................32
3.2Nitrogen .......................................................................................................................................32
3.3Phosphorous ...............................................................................................................................33
3.4Potassium ....................................................................................................................................34
3.5Other important nutrients:...........................................................................................................34
3.6Micro or trace elements (nutrients needed in smaller quantities)...............................................34
3.7Soil acidity ...................................................................................................................................35
4SOIL ENRICHING METHODS ............................................................................................................37
4.1Trench beds ................................................................................................................................37
Introduction..................................................................................................................................37
Shallow trench .............................................................................................................................40
Eco-circles ...................................................................................................................................40
4.2LIQUID  MANURES ....................................................................................................................42
4.Good plants for liquid manures.......................................................................................................43
Comfrey.......................................................................................................................................43
5.How to make liquid manure from animal manure...........................................................................44
Kraal manure (cattle) ...................................................................................................................45
Chicken manure..........................................................................................................................45
Goat manure ...............................................................................................................................45
Other manures............................................................................................................................46
Urine ............................................................................................................................................46
Agroforestry Leaf tea Recipe......................................................................................................46
4.3Manure as a natural fertilizer.......................................................................................................46
5NATURAL PEST AND DISEASE CONTROL ......................................................................................48
5.1Enemies or friends......................................................................................................................48
5.2Plants...........................................................................................................................................48
5.3Diagnosing plant problems..........................................................................................................51
Ways to identify insect damage..................................................................................................51
Ways to identify disease damage...............................................................................................51
5.4Bio-Indicators..............................................................................................................................52
5.5Biological pest control .................................................................................................................53
Beneficial insects.........................................................................................................................53
Advantages of biological control................................................................................................. 53
Disadvantages of biological control............................................................................................54
Pollinators ....................................................................................................................................54
Scavengers................................................................................................................................. 54
Physical control methods ............................................................................................................55
Protective borders and barriers...................................................................................................55
Traps...........................................................................................................................................55

Artificial guards ............................................................................................................................56

Botanical remedies..................................................................................................................57

6MIXED CROPPING .............................................................................................................................58

6.1Inter-planting ...............................................................................................................................58

Examples of inter-cropping in a vegetable garden.....................................................................58

Some plants which grow well together:.......................................................................................59

Plants that do not grow well together:.........................................................................................60

6.2Crop rotation................................................................................................................................61

Effects of crop rotation................................................................................................................61

1 WATER AND SOIL CONSERVATION PRACTICES FOR SMALLHOLDER FARMERS.

1.1 WATER HARVESTING AND CONSERVATION CASE STUDY

The practice of rainwater harvesting for domestic use and crop production supported early civilisations

some 3000 years ago. Today, rainwater harvesting remains a highly productive and sustainable practice

which is widely used by small producers and commercial farmers alike.

What follows is a description of the well-known case of Mr Phiri Maseko, a Zimbabwean farmer whose 3

ha farm is an excellent example of rainwater harvesting and water conservation.

Poor soil conservation practices and deforestation in the upland areas of Zimbabwe have led to massive

soil erosion and land degradation. The result is that in a country where 70% of the population relies on

agriculture for a living, only 20% of the land can be used for this purpose. Many farms have become

unproductive, and those which are marginally productive cannot survive recurring drought. As a result,

many farmers have abandoned their farms, while others have been forced into subsistence farming.1

The Vishavane District in the Midlands

Province of Zimbabwe is a particularly dry

area with frequent droughts, and the

farmers who live here struggle with fragile

soils and erratic rainfall. However, on one

farm in this region, a three-hectare rural

homestead located in a hilly area outside

the small town of Zvishavane, crops grow

quickly and bountifully. Here, enough food

is produced to support a family of 15 and

to raise money for other living expenses.

This is the farm of Zepheniah “Phiri”

Maseko, a farmer who views natural

resources such as soil and water as

precious gifts to be respected and

protected, and whose innovations in soil

and water conservation have drawn

international attention and acclaim.

Figure 1.1A view from the top of the Maseko farm

Figure 1.3The Maseko family homestead

When Phiri first began farming he found it very difficult to grow crops

successfully, as he had few material resources and there were often

periods of drought. He decided to pay close attention to what happened

when it did rain, and through careful observation he learned how the water

flowed over and into the land. Phiri then began to experiment with ways of

capturing the water in the soil so that it could provide nourishment for his

crops and trees.

The Maseko Farm:

Phiri’s plot is situated on

the slope of a hill which

faces north-northeast,

providing good winter sun.

At the top of the hill is a

large rock outcrop (a

granite dome). This rock

outcrop posed the first

challenge for Phiri. He

observed that when heavy

rains fell, the rock caused

water to run down the hill in

channels, taking soil with it

and causing severe

erosion. Phiri also noticed

that although in this

situation very little water

was able to infiltrate the

soil, the soil remained

moist for longer in areas

just above rocks and plants

and in small depressions.

Based on these

observations, Phiri decided

to try and control the flow

of storm water off the rock.

He built some low stone

walls at random intervals

along contours below the

rock outcrop. The walls

slow down and spread out

the flow of storm water.

Patches of indigenous

vegetation which grow

along the walls also slow

the water down and draw it

into the soil.

Figure 1.2Mr Phiri

Maseko

Below the stone walls Phiri then dug two dams, into which the water could be directed. Phiri calls the

larger of the dams his “immigration center”. “It is here that I welcome the water to my farm and then direct

it to where it will live in the soil,” he says.3 Water in this dam seeps into the ground over a period of time,

replenishing the store of water under the ground. The dam has also become a water gauge for Phiri, who

has learned that if it fills up three times in a season, enough rainwater will have seeped into the ground to

see his farm through two years of drought.

Water overflow from the smaller dam is directed by pipe into a storage tank. This water is used to water

the homestead garden, where Phiri and his family grow an unusually wide variety of fruit and vegetables

such as pumpkins, beans, cabbage, tomatoes, garlic, peas, onions, carrots, chillies, guavas, oranges,

naartjies, lemons, paw-paws, peaches and mangos.

Phiri also built a concrete tank next to the main

house. When it rains, water runs down the roof and

along gutters into the tank, where it is stored for

drinking and household use. A granadilla creeper

was trained to grow up and over the tank to keep the

water cool. All of the water which the family uses for

washing (called greywater) is drained into an

unsealed underground tank, where it quickly seeps into the ground.

Between the family homestead and the crop area is a dirt road. To

control the water runoff from the road, Phiri dug large pits (4m long,

2m wide and 1m deep) at regular intervals just above the fields and

planted indigenous vegetation around them. When it rains the pits fill

with water, which seeps into the soil slowly, feeding the plants and

replenishing the water table. The vegetation stabilises the pits and

prevents them from collapsing.

The family grows many different crops in their

fields, including maize, sorghum, beans,

pumpkins, millet, watermelon, nuts, cassava,

peas and sweet potatoes. This diversity gives

the family food security because if some crops

fail, others will survive. Their crop diversity also

reduces the likelihood of pest attack and

prevents the soil from losing its nutrients.4 Phiri

also built three wells in the cropping area. One of

these is carefully protected so that the water can

be used for drinking. The other two are used for

irrigation and for washing clothes. A network of

pipes and canals has also been constructed so

that crops can be watered during times of drought.

At the lowest point of the farm lies a natural wetland, an area of land where the soil is saturated with

water. Here, Phiri dug two ponds. The larger pond is stocked with fish which are caught for food, while the

smaller pond catches water overflow from the larger one. Phiri planted reeds, bananas, kikuyu and

elephant grass, and sugarcane around the banks to hold the soil in place. Water from the main pond can

also be pumped out and used to water the crops.

As well as observing the ways in which water moves, Phiri also paid close attention to rainfall patterns

and has experimented with numerous other water-harvesting methods over the years. Phiri uses the soil

Figure 1.4 Rainwater is directedinto dams

Figure 1.5 Water overflow is directed into a

storage tank

Figure 1.6 Pits which store water

Figure 1.7 Members of the Phiri homestead standing next to their

maize crop

Figure 1.8 The water harvesting and conservation

process

as his “catchment tank” so all of his methods are designed to help water sink into the soil as quickly as

possible.

Through observation, inspiration, innovation and dedication, Phiri Maseko changed the landscape not

only of his farm, but also of his life. In 1986 he founded the Zvishavane Water Project, a Non-Government

Organisation (NGO) which was established to educate people about water harvesting and conservation

and to promote sustainable farming. Phiri spreads his knowledge and skills freely and tirelessly to

anybody who is interested in learning about water harvesting and conservation. Since 1997 more than a

thousand people from outside the region have visited the Maseko farm, and “…local visitors are so

frequent and numerous that he (Phiri) has ceased to count them.”5 In 2006, Phiri Maseko was presented

with the prestigious National Geographic Society/Buffett Award for Leadership in Conservation, to

acknowledge his outstanding work and lifetime contribution to further the understanding and practice of

conservation in his country.6

There are many different ways to conserve water by protecting and managing it efficiently. In situations

where water is used for irrigation, conservation involves getting as much water as possible to infiltrate the

soil so that the amount of water lost to evaporation or runoff (water which runs over the ground) is

minimised. One method of achieving this is to cover the soil with a mulch such as a crop residue, which

increases water infiltration and reduces evaporation.

Other examples of water conservation practices

include recycling and re-using water (e.g. using bath

water to water vegetables); irrigating crops in sensible

ways (e.g. watering less often but more thoroughly,

and not watering during the heat of the day);

eliminating water leaks (e.g. fixing leaking taps and

pipes); and growing indigenous plants which are

suited to the local climate and environment.

Based on the above definitions, as well as the

practices of people such as Phiri Maseko who harvest

and conserve water, we can say that water harvesting

and conservation involves:

1.2 OVERVIEW OF WHCMETHODS

There are many different forms of water harvesting and conservation. The methods selected for this

manual are summarised in below, along with a short description of what each method entails. Many of

these methods can be used together and complement each other well. In this manual, the methods that

have been grouped together have differences too small to detail. Alternate names have been listed.

There are also some important and useful methods noted at the end of the table. These methods, many

of which are commonly known like small earth dams, may be needed and suitable to some situations, but

design and construction are somewhat technical. Water conservation measures and water storage

structures are usually identified separately from water harvesting, although these are used as part of

water harvesting systems.

Type

Water flow when raining

Collection area

relative to growing area

Intercepting / capturing rainwater

Slowing the water down

Channelling the water to where it is

needed

Storing the water (a) directly in the soil,

or (b) in tanks or storage containers

Micro-catchment:

Sheet flow of water.

10 x growing area

Macro-catchment:

Channel flow of water

100 x growing area

Floodwater harvesting:

Flood events

up to 10,000 x growing area

Name Used in

Manual

Similar to :

Description

Main purpose or comment

Type of Water Harvesting

System

diversion

furrows

•run-on ditches

•run-on RWH

•ex-field RWH

•feeder channels

•diversion

trenches

A diversion furrowdirects rainwater

runoff from gullies, grasslands or hard

surfaces (such as paths or roads) to a

cropped area or to a storage tank. This

increases the water available to the

plant.

•used for fieldcrops and in

gardens

•additional water diverted

directly to soils and crops

•additional water stored in

underground tanks for later

watering

Macro-system (collects water

from an external catchment and

brings it to the field).

trench-beds

•deep trenching

•fertility trenches

Trench beds are 1m wide and 2 m

long. They are dug to 1m deep then

packed with dry grass/leaves, compost,

manure and soil.

•used in food-gardens

•create highly fertile soils which

can absorb and store water.

•provide an immediately usable

planting bed even on shallow

or poor soils.

•often used with diversion

furrows and mulching.

A micro-system when used

alone. But these are usually

connected to diversion furrows

which collect water from an

adjacent area and feed the

trenches.

mulching

•no other names

Mulching is the practice of spreading

organic material like compost, straw,

manure, dry leaves, grass clippings or

wood chips onto the surface of the soil.

It is usually concentrated around the

plant.

•can be used on all crops and

orchards, not pastures.

•improves plant growth

•reduces evaporation from the

soil surface

•improves soil temperature

•limits weed growth and makes

watering easier by protecting

soil.

Water conservation method

Name Used in

Manual

Similar to :

Description

Main purpose or comment

Type of Water Harvesting

System

stone bunds

•stone lines

•stone banks

•contour stone

bunds

Stone bunds are rows of tightly packed

stones built along contour lines

•used to improve grazing land

•slow down, filter and spread out

runoff water

•increase infiltration and reduce

soil erosion.

•sediment is slowly captured on

the upper sides and they form

natural terraces.

Macro-system: The contour

ridges collect water from

adjacent slopes.

tied ridges

•in-field RWH

•partitioned

furrows15

•cross-ridges

•furrow dikes16

Earth ridges are built along the contour

at 3m spacing. Crops are planted on

either side of the ridge. Rainfall from the

unplanted sloping basin is caught in the

furrow and ridge. Basins are created

along the contour to further pond runoff

using crossties – mounds of soil spaced

along the base of the contour.

•Used in home-gardens,

smallholder fields and when

mechanised, at a large

commercial scale.

•the system has been fine-tuned to

South African conditions and is

called “in-field RWH” in local

publications.

Micro-system when used

without other methods. Can

be used with diversion

furrows and mulching.

swales

•bunds

•contour ridges

•berm ‘n basin

•contour ditches

A swale is an earth bank constructed

along the contour with a furrow on the

up-slope side – this is filled with dry

leaves, compost and soil. The top of the

earth bank is levelled off to allow

planting. The swale intercepts runoff,

spreads it out and helps it infiltrate deep

into the ground.

•Used in home-gardens and

smallholder fields.

•widely used within permaculture

systems.

•good groundwater recharge

Micro-system, but like the

above, often used with

diversion furrows and

mulching.

Name Used in

Manual

Similar to :

Description

Main purpose or comment

Type of Water

Harvesting System

terraces

•benches

A terrace is a level strip of soil built

along the contour of a slope and

supported by an earth or stone bund, or

rows of old tyres filled with soil. Terraces

create flat planting areas and stabilize

slopes which would otherwise be too

steep for crop production.

•Used in home-gardens and

smallholder fields.

•mainly in steeper sloping areas,

for cropping and orchards.

Micro-system used on

steeper slopes. Diversion

furrows not used to

augment water – erosion

risk on steeper slopes.

Mulching can be used.

fertility pit

•banana circles

•circular swale

•Katumani pitting

Fertility pits enable runoff water to be

captured and conserved in 1m deep pits

that are filled with organic matter such

as compost or manure. The organic

matter increases the fertility of the soil

and minimises the loss of water from

evaporation.

•Used in home-gardens and

smallholder fields.

•often planted with wet-loving

bananas / paw paws

•often used in conjunction with

greywater.

Micro-system which

lends itself as a soak

away around buildings –

including greywater.

Katumani pitting is a

variation where multiple

fertility pits are tightly

packed across a field.

greywater

harvesting

•recycling

•re-use

Greywater harvesting is the practice of

using non-toilet wastewater produced in

a household – to water the root zone of

the soil. Examples include tower

gardens nad keyhole beds

•home-gardens

•greywater includes the water used

for bathing, washing, cleaning,

cooking and rinsing.

Water conservation

method

roofwater

harvesting

Collecting water from roofs for

household and garden use is widely

practiced across South Africa. Tanks

and containers of all types – from brick

reservoirs to makeshift drums and

buckets – are a common sight in urban

and rural areas.

•mainly used for domestic supply

•surplus used in home-gardens

•more greywater available

Macro-system – because

it is a large collection

area to storage.

1.3 CATCHMENTS

A water catchment is an elevated area of land from which water drains to a particular endpoint. Each

catchment is separated topographically from adjoining catchments by geographical barriers such as

ridges, hills or mountains; these barriers are called watersheds. A ridge along a mountain, for

example, creates two catchments, each of which faces a different direction. Elevated catchments

drain into lower

catchments, so a large

catchment will include

many smaller catchments

at lowerelevations.

Figure A water

catchment

No matter where you are,

the ground on which you

stand forms part of a water

catchment. The figure

below, for example, shows

an urban water catchment.

The crosses show the high and low points of the plot, while the arrows indicate the run-off water.

Figure An urban water

catchment

1.4 TOPOGRAPHY –ASPECT AND SLOPE

Aspect

The direction which a site or slope faces is called its aspect, and aspect is important to consider when

planning a vegetable garden. Plants need to receive at least 5 hours of sunlight a day, so it is

important to choose a site where plants will get maximum sunshine all day long. Beds which lie in an

east-west direction will get the full benefit of both the morning and the afternoon sun.

The following method can be used to determine the aspect of a site:

Figure 6.1 How to determine aspect(Method 1)

Point with your right hand to where the

sun rises (east), and with your left hand

to where it sets (west). When standing

in this position, you will be facing north,

and south will be directly behind you.

Once you know where north is, you can

determine the direction that the site

faces.

Slope

The slope of the land is the angle it forms with the plane of the horizon. Slope is important to take into

account when planning a vegetable garden as flat sites are are easy to work on and soil erosion and

water loss is minimised. Care should be taken, however, on flat sites with clayey soils as waterlogging

may become a problem.

Slope also needs to be taken into account when planning and implementing most WHC methods,

mainly to ensure that soil erosion does not occur.

Slope can be expressed in the following three ways:

Proportion–this is the ratio of a slope’s horizontal distance to its vertical distance.1 For example, a

1:4 slope rises a vertical distance of one unit for every four units it extends horizontally.

Degrees – this is a measurement used to represent the angle of a slope. Degrees can be measured

with a protractor or with survey instruments. Land that is completely flat (horizontal) is 0°, while a

vertical cliff is 90°.

90°

45°

0°

Percentage – the percentage of a slope can be calculated using the following formula:

Example: A slope of 1:4, where one unit equals 10 metres, has a rise of ten metres and a run of

forty metres. The percentage of the slope (S) can thus be calculated as follows:

The following slopes are expressed in proportion, degrees and by percentage.2

Marking out contour lines on a slope using a line level

Three people are needed to mark out contour lines on a slope using a line level (person A, person B

and person C).

(Not to

scale)

1,Start at the edge of the field.

Person A holds their pole in a vertical position and stands still, while person B moves up and/or down

the slope until the line level, which is read by person C, gives a level reading. Points A and B are then

marked with pegs.

2.Person A then moves to point B, and person B moves further down the field and the process

is repeated.

3.Note that when marking out contours using a line level, it is important that both poles are held

vertically, and that neither pole is placed in a depression or on top of a minor high spot such as a rock

or clump of soil.

Measuring slope using a line level

A line level is another levelling device which is also inexpensive and easy to make by hand (refer to

Section 6 for information on how to construct a line level). Three people are needed to measure the

percentage of a slope using a line level (person A, person B and person C).

S(%) = x 100 = 25%

1:1 = 45° = 100% 1:2 = 26° = 50% 1:3 = 18° = 33.3%

rise

Slope (%) = x 100

run

1000 mm

10 000

450

(Not to

scale)

Figure 6.2Using a line level to measure slope

1.Person A stands upslope of person B and adjusts the string down the

pole until the line level attached between the poles gives a level reading. This

reading is taken by Person C.

2.The percentage of the slope is then calculated using the formula:

rise

Slope(%) =x 100%

run

3.The run is the distance between the two poles, which should be 10 000 mm (10 meters).

The riseis the difference in height of the string, which is calculated by subtracting the height of the

string on pole A (e.g. 450 mm) from the height of the string on pole B (e.g. 1000 mm).

1000 –450

4.Slope(%)= x 100%

10000

= 550

x 100%

10 000

= 5.5 %

5.Note that when measuring slope using a line level it is important that both poles are held

vertically and that neither pole is placed in a depression or on top of a minor high spot such as a rock

or clump of soil.

Table for the conversion of angles and degrees of slope to percentages, with the

recommended distances between the contour lines.

Degrees

Percentage

Recommended distances between contour lines in

metres (m)

1.7

57.3

3.5

28.7

5.3

19.1

7.0

14.3

8.8

11.5

10.5

9.6

Figure 6.3A level

reading on a line level

12.3

8.2

7.2

6.4

17.6

5.8

19.4

5.2

21.3

4.8

23.1

4.5

25.0

4.1

27.0

4.0

28.7

3.6

30.6

3.4

32.5

3.2

34.4

3.1

36.4

3.0

38.4

2.8

40.4

2.7

42.5

2.6

44.5

2.5

46.6

2.4

48.8

2.3

51.0

2.2

53.2

2.1

55.4

2.1

≥30

≥57.7

2.0

2 HEALTHY SOILS

2.1 HEALTHY SOIL IS ALIVE.

Soils supply essential nutrients, water, oxygen (air) and root support to plants.

Healthy soil is living soil. It contains many living organisms. It is deep, loose, and easy to dig and full

of air and water. Healthy soil has aggregates or structures (that look like bread crumbs) that create

air pockets allowing water to infiltrateor move deep into the soil. Healthy soils act as giant moisture

holding sponges, which is very important in times of drought and flooding.

Healthy soils are naturally fertile and able to supply sufficient amounts of nutrients to plants. To do

this the soil needs a continuous supply and build-up of organic matter. Soil health and it’s fertility have

a direct influence on the nutrient content of food crops.

We are what we eat. Healthy soils lead to healthy plants and healthy people

2.2 CARBON AND SOIL ORGANIC MATTER - THE MAIN BUILDING BLOCK OF LIFE AND SOIL

A key element of all living things, carbon, is constantly cycling through nature as either a liquid a solid

or a gas. Soil carbon is sometimes also called organic matter. Because carbon is the main building

block of all organic molecules, the amount in a soil is strongly related to the total amount of all the

organic matter— the living organisms plus fresh residues plus well decomposed residues.

Figure 1: The Carbon cycle (From:

https://commons.wikimedia.org/wiki/File:Carbon_cycle.jpg#/media/File:Carbon_cycle.jpg)

This diagram of the carbon cycle shows the movement of carbon between land, air and oceans in

billions of tons of carbon per year. Yellow numbers are natural flows, red are human contributions and

white numbers indicate stored carbon, usually in liquid or sold form.

More than 90% of the world’s carbon is found in the deep ocean. ON land, around 805 of carbon is in

the soil.

An excess of carbon dioxide (CO2) in the earth’s atmosphere is warming the planet and increasing

the size, number and intensity of extreme weather events. Some of this excess CO2 is dissolving into

the world’s oceans causing them to become acidic.

2.3 WHY SOIL ORGANIC MATTER IS SO IMPORTANT

Organic matter has an overwhelming effect on almost all soil properties, although it is generally

present in relatively small amounts. A typical agricultural soil has 1% to 6% organic matter. It consists

of three distinctly different parts—living organisms, fresh residues, and well decomposed residues.

These three parts of soil organic matter have been described as the living, the dead, and the very

dead.

SOM composition; Carbon = 42%, Oxygen = 42%, Hydrogen = 8%, Ash = 8%, Macronutrients (N, P,

K, S, Ca, Mg),Micronutrients (Fe, Mn, B, Zn, Cu, Cl, Co, Mo, Ni)

Figure 3: Functions of SOM

The living part of soil organic matter

includes a wide variety of

microorganisms, such as bacteria,

viruses, fungi, protozoa, and algae. It

also includes plant roots, insects,

earthworms, and larger animals, such

as moles and rabbits, that spend some

of their time in the soil. The living

portion represents about 15% of the

total soil organic matter.

These different types of organisms:

•Help to control insect

pests, weeds and plant

diseases

•Form beneficial symbiotic

relationships with plant

roots

•Recycle plant nutrients from soil organic matter and minerals back to roots and

•Improve soil structure.

Figure 4: Micro-organisms and small living creatures in the soil (From: Life in the Soil –

www.wunderground.com)

In a teaspoon of healthy soil there are more microbes than there are people on earth.

Microorganisms, earthworms, and insects feed on plant residues and manures for energy and

nutrition, and in the process they mix organic matter into the mineral soil. In addition, they recycle

plant nutrients. Sticky substances on the skin of earthworms and other substances produced by fungi

help bind particles together. This helps to stabilize the soil aggregates, clumps of particles that make

up good soil structure. Organisms such as earthworms and some fungi also help to stabilize the soil’s

structure (for example, by producing channels that allow water to infiltrate) and, thereby, improve soil

water status and aeration. Plant

roots also interact in significant

ways with the various

microorganisms and animals living

in the soil.

Figure 5: A healthy soil has lots of

organic matter, earthworms and

other tiny animals in it.

The fresh residues, or “dead”

organic matter, consist of recently

deceased microorganisms, insects,

earthworms, old plant roots, crop

residues, and recently added manures. This part of soil organic matter is the active, or easily

decomposed fraction and is the main supply of food for soil organisms As these organic materials are

decomposed by the “living,” they release many of the nutrients needed by plants and they also create

humus. Organic chemical compounds produced during the decomposition of fresh residues also

help to bind soil particles together and give the soil good structure.

The well-decomposed organic material in soil, the “very dead,” is called humus. Micro-orangisms

turn the simple sugars or liquid carbon exuded from plant roots into humus. These simple carbon

compounds are joined together into more complex and stable molecules. The formation of stable

humusrequires a large number of different kinds of soil microbes, including mycorrhizal fungi,

nitrogen fixing bacteria and phosphorus solubilising bacteria, all of which obtain their energy from

plant sugars (liquid carbon).

The types of fungi that survive in conventionally managed agricultural soils are mostly decomposers;

they obtain energy from decaying organic matter

such as crop residues. Generally, these kinds of

fungi have relatively small hyphal networks. They

are important for soil fertility and soil structure, but

play only a minor role in carbon storage.

: One principle of nature is that the more

biodiversity there is in a system, the healthier and

more resilient it is

Right: Mycorrhizal fungi grow very closely

associated with plant roots and create networks of

filaments (hyphae) within the soil

(From: http://www.heartspring.net/mycorrhizal_fungi_benefits.html)

Mycorrhizal fungi differ from decomposer fungi in that they get their energy in a liquid form, as

solublecarbon directly from actively growing plants. There are many different types of mycorrhizal

fungi. Mycorrhizal fungi access and transport water - plus nutrients such as phosphorus, nitrogen and

zinc - in exchange for carbon from plants.

Some of this soluble carbon is also channelled into soil aggregates via the hyphae of mycorrhizal

fungi and can undergo humification, a process in which simple sugars are made up into highly

complex carbon polymers. The soil conditions required for humification are reduced in the presence

of herbicides, fungicides, pesticides, phosphate and nitrogen fertilizers - and enhanced in the

presence of root exudates and humic substances such as those derived from compost.

Humus holds on to some essential nutrients, storing them for slow release to plants. Humus also can

surround certain potentially harmful chemicals and prevent them from causing damage to plants.

Because it is so stable and complex, the average age of humus in soils is usually more than 1,000

years. The already well-decomposed humus is not a food for organisms, but it’s very small size and

chemical properties make it an important part of the soil.

Good amounts of soil humus can reduce drainage and compaction problems that occur in clay soils

and improve water retention in sandy soils by enhancing soil aggregation.

Figure 6: Adding organic matter results in many changes in the soil. (From Building soils for better

crops, 2009)

ORGANIC MATTER INCREASES THE AVAILABILITY OF NUTRIENTS . . .

Directly

•As organic matter is decomposed, nutrients are converted into forms that plants can use directly.

•Cation Exchange Capacityis produced during the decomposition process, increasing the soil’s ability to

retain calcium, potassium, magnesium, and ammonium.

•Organic molecules are produced that hold and protect a number of micronutrients, such as zinc and

iron.

Indirectly

•Substances produced by microorganisms promote better root growth and healthier roots, and with a

larger and healthier root system plants are able to take in nutrients more easily.

•Organic matter contributes to greater amounts of water retention following rains because it improves soil

structure and thereby improves water-holding capacity. This results in better plant growth and health and

allows more movement of mobile nutrients (such as nitrates) to the root.

2.4 TURNING AIR INTO SOIL

The process whereby carbon dioxide is converted to soil humus has been occurring for millions of

years. Rebuilding carbon-rich topsoil is a practical and good option for productively removing billions

of tonnes of excess carbon dioxide from the air. When soils gain in carbon, they also improve in

structure, water-holding capacity and nutrient availability.

The formation of healthy soilrequires photosynthesis to capture carbon dioxide in green leaves.

Plants use energy from the sun, carbon dioxide from the air and water and minerals from the soil to

make up their food. Food is usually made in the green parts (often the plants leaves).The process of

making food using chlorophyll and sunlight is called photosynthesis. When plants photosynthesize

and make carbohydrates in their chloroplasts, they use some of those compounds for their cells and

structure, and some they burn for their life energy.

But they “leak” or exude a significant amount of these

compounds as “liquid carbon” into the soil. Microbes

use this energy to create complex stable forms of soil

organic matter, or humus.

One of the more remarkable things that soil scientists

are learning about plants and soil organisms is that

they seem to have co-evolved in a mutually beneficial

relationship. As we have learned more about soil

biochemistry we have discovered that, through root

exudates, plants are able to control their local

environment – to regulate the local soil

microorganisms, to cope with being eaten by

animals, to bring distant nutrients closer, to alter the

chemical and physical properties of nearby soil, and

to inhibit the growth of competing plants.

Figure 7: Photosynthesis (from:

mages.wisegeek.com/photosynthesis-process-

diagram.jpg)

Between 20-40% of the sugars produced by plants

are exuded through their roots to the rizosphere.

The zone of soil around the roots (the rhizosphere) provides an ideal habitat and good supplies of

energy-rich organic matter. In return, microbes around the root release nutrients and plant-growth

promoting compounds, while at the same time providing a level of suppression against plant

pathogens. As microbial activity increases, the conversion of soil organic matter to humus increases

which also results in carbon sequestration. The formation of gum and polysaccharides by microbes

and earthworms promotes the formation of stable soil aggregates and increases the ability of the soil

to retain plant-available water and nutrients.

Everything goes round and round in a continuous cycle

Figure 8: The Nutrient cycle> All the goodness (nutrients) from fruits, leaves, branches, whole plants,

animal manure and dead animals decompose and go back into the soil. The nutrients are taken up by

plants in the soil, with the help of microbes and in this way are recycled (used again and again). The

life of a plant is therefore a cycle and nothing is ever wasted.

(From:http://www.sswm.info/category/concept/nutrient-cycle)

2.5 CHARACTERISTICS OF HEALTHY SOIL

The complex interaction between the physical, chemical and biological properties of the soil has a

major influence on soil fertility

and health.

Figure 9: Soil Health depends

on physical, chemical and

biological characteristics

Although creating a healthy soil is

mostly a biological process, it is

influenced by the interactions that

occur between the physical,

chemical and biological

components of the soil. Biological

activity is driven by temperature,

and requires appropriate levels of air, water and suitable nutrition. The physical properties of the soil

will affect air and water exchange, which will influence biological processes such as respiration. This

in turn will influence the ability of soil organisms to decompose organic matter and release nutrients

for uptake by plants. The activity and diversity of soil organisms is also influenced by soil chemistry

e.g. pH. The growing plant, and more specifically the activity of roots and material released from roots

(exudates etc), also plays a significant part in maintaining microbial activity.

Physical components

The physical properties of soil are determined by the balance between sand, silt and clay particles,

which determines soil texture. These particles combine with various forms of organic matter to form

soil aggregates. The size and distribution of these aggregates through the soil profile determines soil

structure, which influences soil stability, erosion risk, ease of cultivation and compaction. Soil

structure directly affects the movement of air and water through the soil profile, which in turn affects

biological activity, root development, crop establishment and tolerance to environmental stress.

Chemical components

The mineral content of the underlying soil parent material has a major influence on soil chemical

properties of the soil. Of particular importance from a soil health perspective is the impact that soil

chemistry has on the development of plant-microbe interactions. For example, soils that are based on

limestone have a tendency to be rich in calcium, andto also be also alkaline, which can restrict the

uptake of nutrients such as phosphorus and manganese.

This in turn can reduce root mass and root exudate production, restricting both microbial activity and

plant response to microbial growth promotion. Soil pH influences microbial populations, encouraging

bacteria to dominate alkaline soils and fungi to dominate acidic soils. A better balance of bacteria and

fungi can be found at more neutral soil pH values. Bacteria require simple sources of soluble organic

matter and have high multiplication rates, while fungi can utilise more complex insoluble forms of

organic matter and have relatively low multiplication rates.

Biological components

During its conversion from plant and animal residues to humus, soil organic matter has a direct impact

on soil health. Un-decomposed organic material provides a food source for macro-organisms such as

earthworms.

Earthworms mix partially decomposed organic matter with soil minerals as the material passes

through the gut, creating channels for air and water movement as they go.

Microbes thrive in the earthworm

casts, completing the conversion of

organic matter to plant-available

nutrients and humus. This humus

can bind sand, silt and clay into

stable soil aggregates, while at the

same time providing exchange sites

for nutrients and improving water

retention. This results in increased

soil fertility and yield potential.

Figure10; An earthworm in a clod of

soil showing the soil channels,

earthworm casts and soil

aggregates. (From H.Smith, 2015)

2.6 WHAT IS SOIL?

Soil contains abundant plant and animal life, as

discussed above. There are four main components of

soil: mineral matter, organic matter, air and water.Soil

minerals are made through the breaking up of the basic

elements or minerals of the earth. These are initially

found in the form of rocks or ‘parent material’. Over a

very long time, these rocks are broken down into small

particles through rain, wind, sun and soil organisms and

mixed with air and water. This becomes soil that can

support plants and micro-organisms to grow. Like people,

plants cannot live and grow without water, air and food.

Figure 11:: A typcial soil profile (From: FARMESA2003. A

study guide for FFS. Soil and water conservation.)

Parent material breaking down to form 1 cm of soil can

take between 200-1 000 years

The mineral matter (45%) is made of sand, silt and clay

size particles—the basic texture of the soil. The soil

water (25%) contains dissolved minerals and is the main

source of water and nutrients for plants. The air (25%) in

the soil is needed for plant roots and soil microorganisms to obtain oxygen. Organic matter (5%)

includes plant and animal materials in various stages of decomposition and is discussed above.

2.7 CHARACTERISTICS OF SOIL TEXTURE TYPES

Sandy soil

Good things about this type of soil

Bad things about this type of soil

It is easy to dig and work with

It warms up quickly in spring after winter

It is good for root crops

Water and air can get into the soil easily

It gets dry quickly

It does not keep much fertility

It does not hold water well

Loam soil (Mixture of sand and clay)

Good things about this type of soil

Bad things about this type of soil

Holds water well

Best for root growth

Contains organic matter, like …..

This soil can be hard when dry

Clay soil

Good things about this type of soil

Bad things about this type of soil

Holds water well and for a long time

Holds fertility well and for a long time

Hard to work; heavy

Slow to warm up in spring

Sticky when wet

Hard when dry

2.8 HOW TO TELL YOUR SOIL TEXTURE TYPE

You can tell how much sand, silt or clay (commonly called texture) is in your soil by how it feels. Wet

some soil and roll it into a ball between your hands. Then roll this little ball into a sausage

Below is a table that describes how you can tell what type of soil you have.

Table 1 : Different soil texture types

oSand makes the soil loose.

oSilt is very fine sand. It holds water and plant food better than rough sand, but it is easily

washed out of the soil.

oClay is the sticky part of the soil that holds it together. It holds water like a sponge.

The best soils according to texture class are called loams and they are an equal mixture of sand, silt

and clay.

It is important to know which soil type you have. Crumbly and loose soil holds the most water and the

most air, which is what plants need to grow. To make your soil more crumbly (whether it is sandy,

loam or clay) you need to keep adding lots of manure, compost and mulch. Never walk on the planted

areas, especially if they are wet.

All types of soil need organic matter to increase their fertility, or plant food. Sandy soil needs to be

given organic matter to increase its ability to hold water and plant food or nutrients. Clay soil needs to

be given organic matter to increase its ability to hold air in the soil and to release the plant foods that

are there.

Another method of identifying the proportion of soil participles in a soil is to conduct a “bottle test”.

To do this, take a bottle and fill a third of it with soil. Pour water into the bottle until it is almost full,

place a lid on and shake it vigorously for a few minutes

in order to separate the soil particles. Leave the bottle to

settle, and note what happens over the next few hours.

You will see that the substances settle in layers, the

heaviest at the bottom and the lightest on top.

The layer of water above the settled material remains

cloudy for a long time because it contains clay particles

which are so small that they stay suspended in the

water. Substances which are lighter than water (organic

matter like leaves, seeds, spores, and insect and

animal waste) float on the surface.

Heavy particles such as gravel, pebbles and sand fall

quickly to the bottom of the bottle.

The finer elements then accumulate – first the silt,

followed by humus and then the fine and very fine clay.

These layers vary in colour and consistency.

Below: Using the bottle test to estimate the proportion of soil components in a sample

Right: Bottle test showing proportion of soil

separates (From: WHC Manual, WRC, 2010)

2.9 SOIL STRUCTURE

Soil structure describes the grouping or arrangement of primary particles (sand, silt, clay and organic

matter) into larger, secondary particles called aggregates. It is the shape that soil takes, determined

by the way in which individual soil particles clump or bind together.

Aggregates are the fundamental unit of soil function and play a role similar to that of root nodules in

legumes, creating a protected space. The aggregate is helped to form by hyphae of mycorrhizal fungi

that create a “sticky-string bag” that envelops and entangles soil particles. Liquid carbon exudates

from plant roots and fungi enable the production of glues and gums to form the aggregate walls.

Inside those walls a lot of biological activity takes place, again fuelled by the carbon exudates. Most

aggregates are connected to plant roots, often fine feeder roots, or to mycorrhizal fungal networks too

small to be seen. The moisture content inside an aggregate is higher than outside, and there is lower

oxygen pressure inside. These are important properties enabling nitrogen-fixation and other

biochemical activities to take place.

Soil structure affects the movement of water and air in the soil, as well as root penetration and

biological activity. For example, a dense

structure greatly reduces the amount of air and

water that can move freely through the soil and

it is difficult for roots to penetrate such soil.

Right: The dispersed soil participles are

clumped together into aggregates

http://www.soilandhealth.org/01aglibrary/010117attrasoilmanual/Soilmgt3.gif

Micro-organisms play an important role in soil aggregate formation and structure. Soil aggregates

protect the soil against wind and water erosion.

Figure 12: Soil aggregates are groups of soil particles that are glued together by microbial and fungal

by products. Very small aggregates group together to form larger aggregates.

Figure 13: Roots, fungal

hyphae, and their secretions

stabilize soil aggregates and

promote good soil structure,

thus preventing compaction.

2.10 IDENTIFICATION OF SOIL STRUCTURE

The structure of the surface layer of the soil is usually weak to strongly granular or blocky, but a

degraded surface layer can be crusted, platy, or structure-less (massive or single grained). This is

important as soil crusting reduces water and air infiltration, destroys soil life and increases run-off and

erosion.

Figure 14: The

different

structures that

soil can take

http://ecomerge.blogspot.com/2010/05/what-soil-aggregates-are-and-how-its.html

The more soil organic matter (SOM) there is in the soil, the more macro-aggregates can form and the

better the soil structure becomes.

Left: The difference in colour and structure caused in a soil by increasing the soil organic matter. And

cover crops growing through a thick layer of organic matter.

http://thegrowingclub.com/2015/02/article-moving-beyond-drought-in-mind-

space/,https://iowaenvironmentalfocus.files.wordpress.com/2014/12/15127396042_c1b408b873_k.jpg

2.11 SOIL DEGRADATION

Degradation most commonly occurs when erosion and decreased soil organic matter levels initiate a

downward spiral resulting in poor crop production. Soils become compact, making it hard for water to

infiltrate and roots to develop properly. Erosion continuesand nutrients decline to levels too low for

good crop growth.

Tillage or ploughing usually starts this degradation process. Fields that have been ploughed a lot tend

to crust, seal and compact more than non-till fields with lots of crop residues and a living plant cover

with active roots and fungi. Tillage also reduces infiltration and the water holding capacity of the soil

due to poor structure and thereby increases water run-off and erosion.

Figure 15: Changes in soil surface and water-flow pattern when seals and crusts develop

It can also reduce the germination of seeds and root growth. It makes the soil a lot more prone to

wind erosion when it is dry.

Right: A dust storm on the farms around

Bloemfontein in the Free State in October

2014.(From: GSA, 2015)

Right: Soil crusting caused by ploughing and

breakdown of soil structure (From:

http://cropwatch.unl.edu/archive/-

/asset_publisher/VHeSpfv0Agju/content/should-

you-apply-uan-and-residual-herbicides-in-a-tank-

mix-on-emerged-corn-

Figure 16: The downward spiral of soil health due to

intensive tillage or continuous ploughing

3 TURNING RUNOFF INTO 'RUN-ON'

This innovative technology is based on the work and experimentation of MaTshepo Khumbane, who

has a beautiful working system at her present homestead near Cullinan. The remnants of a similar

system in her former homestead plot near Tzaneen of some 20 years ago, still nourishes the fruit

trees there, even though the present owners are unaware that there is a system at all! This system is

the product of years of experimentation with practises in rainwater harvesting and storage.

MaTshepo's run-on system has been studied and documented, so that it could be used as an

innovation that could be introduced to other householders in their circumstances.

Compare this photo to the diagram overleaf.

Run-on is ‘automatic irrigation when it rains.’ The soil in the garden is shaped to catch rainwater

runoff, slow it down and lead it gently to where it is needed. The water dams up in pathways between

deep-trenched planting beds, giving it time to seep into the planting soil. The layout allows excess

water to escape before it can erode the planting beds or the pathways themselves. Such excess

water can either run further down-slope to a storage structure (tank or dam) for future use, or be

released into the veld to continue on its natural course downstream to the river.

Interestingly, the run-on system works with water flows above and below ground.

In its simplest form, the run-on system concentrates surface runoff from adjacent areas into the root

zone of the planting beds. This in itself dramatically increases the effectiveness of rainfall – even in

high rainfall areas, where a large percentage of rainfall may run off unutilised once the top soil layers

are wet.

MaTshepo’s run-on &

trench bed garden

Further, as people’s understanding deepens on what happens to water below the soil surface in their

own conditions, they can start manipulating these flows –with cut-off trenches and by creating

strategically placed impermeable layers in their deep-trenched beds

A A trench (the top ditch) is dug across the runoff slope of the land to catch rainwater.

Below the top ditch, the vegetable beds are dug 1m deep and filled with organic matter —

grass, leaves, manure, and ash —and mixed well with topsoil. These trench beds are fertile

and absorb and retain moisture.

The trench beds are edged with ridges. Some are re-enforced with stone to stop the soil

washing away and to reduce evaporation.

Between the trench beds a network of depressions (rainwater flow paths) connect the top

ditch to a second one at the bottom edge of the garden. The rainwater flows and pools in

these channels/depressions during rain.

These rainwater flow paths are also the footpaths to access the trench beds.

In the rainwater flow paths the gradient is flat so that the water has more time to soak into the

trench beds.

If it rains too much, the bottom ditch is breached to avoid flooding of the trench beds.

A water catchment area: concrete paving around the house is lipped and slopes down to

pipes which lead to further ditches and deep trenches downhill of the house.

Lower down a 2 x1m hole (open pond) catches and stores more run-off.

Fruit trees are planted along the lower edge of a ditch so that their deep roots can benefit

from the extra soaking.

3.1 SOIL FERTILITY

All living things are composed of the basic elements of the earth. Plants consist mainly of hydrogen,

oxygen, carbon, nitrogen, phosphorus, potassium and smaller quantities of magnesium, sulphur and

calcium as well as many other elements in very small amounts (these are called trace elements).

Plants need three main kinds of nutrients:

Nitrogen (N)– for healthy leaf and stem growth;

Phosphorus (P)– for healthy roots and fruit formation;

Potassium (K)– for general health and healthy flowers and fruit.

The capital letters in brackets (N, P, and K) are called the chemical symbols. If you buy fertilizer or

other chemicals, they may use these letters instead of writing out the name in full.

All three of these foods are found in good compost or manure. You can also increase the amount of

these foods in the soil by mulching with leguminous leaves like beans, peas, pigeon peas and Acacia

(thorn tree leaves) or comfrey, using liquid manures, earthworm castings and effective micro-

organisms. You will need to make the earthworm castings and effective microorganism brews and

add them to your soil.These are different ways of improving fertility that you will need to be shown.

3.2 NITROGEN

1.How do you know if your soil needs more nitrogen?

You will know your plants need nitrogen when the leaves are turning

yellowish, instead of a strong bright green.

2.How can you add nitrogen to your soil?

This element is found in most manures (cattle, sheep, pig, goat,

chicken and rabbit). There is more nitrogen in chicken and goat

manure. These must be dried before being used in the garden.

Otherwise they can be too strong and ‘burn’ the plants.

3.Nitrogen is also found in legumes

These are plants that form nodules or little knots on their

roots. These nodules ‘fix’ nitrogen from the air, so that the

plant can take it up through its roots. There are

microorganisms (bacteria) in the roots that help to ‘fix’ the

nitrogen. After the roots of the plant die the nitrogen is

released into the soil and can be used by surrounding

plants.

Examples of legumes that we often grow:

Ground nuts, peas, cowpeas, beans (including

soya beans)

Nodules on the roots that fix

nitrogen

The bacteria in the root knots binds free nitrogen from air

in the soil and release nitrogen after the plant dies

There are less common crops and also many long living plants and small

trees that also fix nitrogen. Some examples are chickpeas, mung beans,

lentils, pigeon peas and tree lucerne.

Some legumes are grown only as green manures, and are not used for food.

These include lucerne, clover, hairy vetch and lupins. These give a lot more

nitrogen to the soil than our food plants, because we dig them into the soil

when they are still green. This is why we call them green manures. We can

also plant our food crops in between these legumes.

3.3 PHOSPHOROUS

1.How do you know if your soil needs more phosphorous?

You will know your plants need more phosphorous when they do not grow fast, as they should. The

leaves may also start to show unusual red or pinkish colours, especially around the edges. If your

plants are small and will not grow, even when compost is added, then you almost certainly have a

severe phosphorous deficiency. This can also be caused by acidity in the soil.

2.How can you add phosphorous to your soil?

Many soils are poor in phosphorous. It is also a bit difficult to add phosphorous to the soil in an

organic way, as most of the sources of phosphorous are tricky to work with. They include urine,

bones, hair, feathers and blood. Usually ,we add these as ingredients to compost

Natural rock phosphate can be added directly to the soil. This is also not easily available. Another

good source of phosphorous is bone meal. You can usually buy this from an agricultural supply store

– but it is not cheap.

One other way of adding phosphorous is to place bones in a fire, for a few hours. You can then grind

them into a powder more easily. This powder can be spread on your garden beds or your compost

heap.

The manure from animals grazing in areas where there is not much phosphorous will also have little

phosphorous. You may need to bring in phosphorous in the form of chemical fertilizer. The usual

source is called Superphosphate. Another chemical fertilizer known as DAP (Di-ammonium

Phosphate) can also be used.

Soya

beans

3.4 POTASSIUM

1.How do you know if your soil needs more potassium?

You will know your plants need potassium when the plants become brittle and the leaf edges become

brown and dry. When fruit do not form properly, you should also suspect a lack of potassium. Other

signs can be hard to distinguish. One of these is a yellowing around the veins of the leaves. This

could also be caused by diseases – so it is difficult to know.

2.How can you add potassium to your soil?

Good sources of potassium are chicken manure and

fresh woodash. Never use ash from coal, as this is

very poisonous to the soil and plants. Another good

source of potassium is a plant known as comfrey. This

plant has large hairy leaves and grows in wet shady

places. The leaves contain a lot of potassium. These

can be used to mulch your vegetable beds and also to

make liquid feeds for your plants (We will look at liquid

feeds later in this section).

The other elements or minerals needed in smaller

quantities, such as Magnesium, Zinc and Iron, are

found in most manure and in compost.

Comfrey is also a good medicine. A tea made from the leaves is good for high blood pressure and

arthritis.

3.5 OTHER IMPORTANT NUTRIENTS:

Calcium (Ca) Promotes plant life and strong plant tissue, promotes early root formation and seedling

growth, aids in the uptake of nutrients, balances pH

Magnesium (Mg) Essential for the formation of Chlorophyll and formation of sugars, a carrier of

phosphate and starches through the plant, promotes the formation of fats and oils, vital for healthy

growth.

Sulphur (S) Increases root development, helps maintain the dark green colour, stimulates seed

production, necessary for protein production, flavor and odour in many fruits and vegetables.

3.6 MICRO OR TRACE ELEMENTS (NUTRIENTS NEEDED IN SMALLER QUANTITIES)

Iron (Fe) Is an oxygen carrier, enhances chlorophyll formation, metabolizes RNA, enhances green

color of produce

Boron (Bo) Promotes early root formation and growth, improves health and sturdiness, increases

yield and improves quality of fruits and vegetables.

Zinc (Zn) Essential for enzymatic reactions in cells and promotes plant growth.

Copper (Cu) Is needed for Chlorophyll production, catalyzes several plant reactions and necessary

for making protein.

Manganese (Mn) Activates many metabolic reactions, increases absorption of calcium, magnesium

and phosphorus, speeds germination and plant maturity.

From: Useful Plants for Land

Design, Pelum

Comfrey

Molybdenum (Mo) Enhances absorption of nitrogen by plants

Chlorine (Cl) Involved in photosynthesis and chlorophyll production, stimulates enzyme activity, helps

control water loss and moisture stress.

Cobalt (C) Is needed in nodules of legumes for nitrogen fixing bacteria

Sodium (Na) Helps in water regulation and photosynthesis

These nutrients are important to plants for health and survival. They are equally important to animals

and human health. This is because we get our nutrients from plants who take up essential nutrients

from the soil. If our soil is healthy our plants benefit by being healthy and we in turn benefit from the

variety of nutrients available.

3.7 SOIL ACIDITY

1.What is soil acidity?

Soil acidity is can influence plant growth and limit crop yield. Minerals or nutrients needed by plants to

grow are dissolved in the water inside the soil. This is a bit like salt or sugar dissolved in a glass of

water.

Soil acidity is when the soil is sour. It is a bit like a glass of water that has vinegar dissolved in it. In

places where it rains a lot, some of the minerals can be washed out of the soil. The soil then becomes

acidic. The use of chemical fertilizers over a long period of time, can also make the soil acidic.

If there is too much acid in the soil, some minerals or plant food will dissolve too quickly and the

plants cannot use them. Other minerals will not dissolve at all, so again, the plants cannot use them.

Phosphorus is one of the minerals that cannot be used by plants when the soil is acidic –even if it is

in the soil.

What causes of acidity?

Acidic parent rock material, high rainfall and leaching elements like calcium (Ca), magnesium (Mg),

and phosphorous (K), decay of organic matter leading to release of organic acids into the soil,

harvesting high yields (therefore removing plenty of Ca, Mg and K from the soil), widespread use of

nitrogen (N) fertilizers.

2.How do you know if your soil is acidic?

You will know your soil is acidic if you provide compost or manure and water for your plants, but they

do not grow. The plants remain small and stunted. This is a common problem.

3.How will you solve the problem of acidity?

The only practical way of dealing with soil acidity is to add lime to the soil. Lime can be bought and is

a white powder, or grey granules.

It needs to be dug into your soil, at least as deep as the roots of the crop you are growing. For

vegetables this is between 30 - 60 cm. This is the width of 1 or 2 spades. You will need to add 1 kg of

lime for every square metre of soil. 1 Kilogram of lime is a spade full. It needs to be heaped high.

For field crops like maize and sorghum that have deep roots this is from 60 cm to 1 meter deep. 1

meter is the length of a spade.

Usually Lime is added 2 or 3 months before planting, as it is slow acting in the soil. If you add Lime at

the same time as you are planting your crop, you will only see the main effect of the Lime in the next

season.

4.Advantages and disadvantages of Liming

Other (easily available) ways of naturally improving soil quality and balancing pH: bone meal, dried

and crushed egg shells, finely crushed sea shells

Advantages

Disadvantages

It is easy to apply, stays in the soil for a

few years, combats soil acidity by

reducing metals’ toxicity, makes P more

soluble and microbes more active,

supplies Ca, Mg to plants, improves soil

structure and water infiltration (reduces

energy needed by roots to penetrate the

soil), improves harvest

It is not easy to determine soil pH,

might not be easy to get, costs

money,

30 cm

Two meters

One meter

4 SOILENRICHINGMETHODS

4.1 TRENCH BEDS

Introduction

A trench bed is a way to increase soil fertility and water holding in your beds and garden. It is an

intensive way of providing good soil for vegetables production on a small scale. It involves digging a

hole and filling it with organic matter, so that your bed can be fertile for a long time (around 5 years).

You will need:

A spade, water, tins, old bones, plastic (if your soils are sandy),

dried grass, wood ash, manure and organic matter.

4.The method

1. Dig a hole 60cm or deeper. It is usually about 1m wide (to

provide easy access, without having to step on the bed) and can

be as long as one likes.

2. Separate the topsoil and subsoil in piles while you are digging.

If your sub-soil is very in fertile it is not used in the trench.

Spread this soil around the garden to help channel water

towards your bed.

3. Place a layer of tins or branches at the bottom of the trench to

help with aeration and also with supply of some nutrients.

The tins need to be squashed before putting them in the

hole. Make a layer of tins about 3 tins deep. If there are

no tins use thin branches instead.

4. Fill the trench with a range of organic materials and

topsoil.

- First add dry grass or weeds (about 10 cm deep)

- Then add manure (about 2 cm deep)

Mandla (in Phuthadjithaba) is digging his trench

bed and placing the topsoil on one pile

(darker soil with more organic matter) and the

subsoil on another (usually lighter soil with

little or no organic matter).

Layer of tins at bottom of trench

- Add also some wood ash (a thin layer, less than

1cm deep).

- Then add a layer of sop soil (about 5cm deep)

Mix these layers with a fork. Stamp them down by

walking on them. WATER the mixture well! Then

start the process again.

You can also add other organic matter like green

and dry weeds and vegetable peelings, card board,

paper and bones.

5. Continue to place the organic materials into the

trench until it has reached ground level again.

6. Now build up the trench bed to about 10-15cm above

soil level. Use a good mixture of topsoil and manure and

or compost.

The organic material in the trench needs to decompose

for about 2-3 months before planting.

7. The other option is to use your trench bed as a seed

bed. In this way, when your seedlings are ready to be

transplanted, the trench bed will be ready to be planted.

Growing seedlings from seed needs a well

prepared bed. The roots of the small plants do not

go down too deep. The materials in the trench can

decompose while the seedlings grow on top.

Above, Carrot and onions seeds are being planted

in a seed bed in Potshini. This trench has just

been prepared.

Note; Fine soil is being used to cover the seeds in

the rows. This is because the seeds are small and

in this way they can germinate better.

A trench bed in Potshini being filled and mixed. Here

the top soil is being added back into the trench Notice

the yellow subsoil on the one side. It is not being used.

A trench bed in Phutaditjhaba being filled, mixed

and stamped down. Notice the mixture of manure,

grass and soil.

Left: In this picture carrot seeds were planted in the smaller trench

bed in the far corner. There are also two tubs of seedlings being

produced. In the foreground is a recently completed trench bed

into which bought cabbage seedlings have been planted. Again

these grew well and did not show any negative effects from the

decomposing material in the trench.

Right: In this picture a number of

trench beds have been prepared

in a garden in Potshini. The owner

has used two of his trenches as

seed beds. They are covered with

grass to hold the moisture in the

soil while the seeds are germinating. This grass will be removed when

the seeds come up.

The middle bed is shaped like a horse shoe. This is a nice design that

makes it easy to reach all sides of the bed. It also allows run-off water

to run into the middle of the shoe and soak into your bed. Here the

owner has planted swiss chard seedlings. They grew well; despite our

fears that the decomposition of the organic matter in the trench bed

may interfere with their growth

8. It is very important that the trenches are watered well while they are being made and afterwards.

The organic material in the trench cannot decompose if it is dry.

Different ways of watering are possible; as long as a lot of water is given!

Advantages and disadvantages of trench beds

In this picture, drip irrigation is going to be used to water a trench bed.

Shallow trench

Shallow trench beds are shallower version of the deep trenches. This trench is dug to about 30cm

deep. The bottom of the trench is filled with sticks and branches. This is covered by a layer of dead

leaves or green leaves and grass (depending on what is available). Then the rest of the hole is filled

with compost and finally it is covered with the topsoil that was dug out.

(from WRC; Homestead water Management Manual, 2009)

Advantages and disadvantages of shallow trenches

Advantages

Disadvantages

Easy to make, takes less energy than a deep

trench, it also takes a shorter amount of time to

create

This is a difficult method if you live in an area with

hard soils and many rocks

Eco-circles

An Eco-circle is a unique, productive way of gardening. Eco-circles are (small) raised, circular garden

pits beds.

1.What you will need to make an eco-circle:

String and a stick, a spade, compost and mulch, seedlings or

seed to plant, a candle and matches, a piece of wire and

used 2l bottle with a lid.

2.How to make an eco-circle:

Advantages

Disadvantages

This method really works as the soil is rich in

nutrients, it is a good method for sandy soils (low in

nutrients)

Difficult to dig trench beds in hard soils, it takes time

and effort, some people are scared of this method

because the trench looks like a grave.

Mark out a circle (using a stick and some string) on the ground where you intend growing food.

Remove the first 20-30cm of topsoil and put it in a pile next to the circle. Remove another 20-30cm

and put it in a separate pile, next to the circle. The hole should be knee deep now (about 50cm)

Light a candle and heat up the wire (careful not to burn

yourself). When the wire is hot, burn 16 tiny holes in the

sides of the 2l bottle. (4 holes, in 4 vertical rows - going

down the side of the bottle).

Place the bottle (upright) in the center of the circle. Now

add a 2cm layer of compost, or decomposed kraal manure,

kitchen waste or dry grass, into the base of the hole. Cover

this with 8cm (4 fingers) of subsoil. Water the 2 layers well.

Continue replacing the subsoil layering it with compost

(grass and or whatever organic material you have) watering

each layer as you go. Having added all the subsoil replace

the top soil. The surface of the bed will be higher than the

surrounding ground. Scoop the soil from the center of the

circle to the outside to create a basin with the top of the

bottle in the center. The basin shape funnels water into the

center where it sinks into the soil. So it can’t run off carrying

precious topsoil with it. Mulch and plant.

Fill the bottle with water once a week. The water will slowly

drip out the bottle into the soil.

3.Practical notes and tips:

The compost creates a sponge which retains water and the mulching prevents evaporation. In areas

of high rainfall the surface of the bed should be flat to prevent water-logging.

You can make the eco circle bigger for example 1m by 1m

Advantages and disadvantages of eco-circles

Advantages

Disadvantages

Easy to make, effective method, small enough to

maintain, saves labour once the circle has been

dug, simple method, not much space needed, can

grow lots of food in the small space, low tech, water

saving method of gardening (there is a saving of up

to 70% in water usage), A good method to use in

dry areas

Could be hard to dig in hard soils

4.2 LIQUIDMANURES

1.Brews for plant nutrition

One way of improving plant nutrition is to make liquid teas or brews that will add fertility to the soil. In

this method nutrients (from plant matter or animal dung) are leached out (drawn out) into water and

applied to the soil. This should be used as an additional soil fertility technique rather than the only

one. Brews provide extra nutrients in case of small deficiencies, but cannot rectify major nutrient

deficiencies.

Liquid manures/brews/ teas are a simple way of giving your plants a boost. The aim is to provide

plants with natural plant foods quickly during their growing season. It is useful for heavy feeders like

cabbages and to give seedlings a boost.

2.How to make liquid manures from plants

A good plant for liquid manure is comfrey. Most soft green leaves and stems can also be used and

weeds are ideal. Avoid plants which are very strong smelling. Plants are made of different quantities

of nutrients and take up different nutrients from the soil. It is best to use a range of plant materials to

make your liquid. Make sure you only use healthy plants.

Make sure your container is clean before you use it. Collect the plant material and fill up the container.

You must keep on adding material to the container every week.

Place a rock on top of the plant material in the container and put the lid on. Do not add water. The

plant material will make its own liquid. If you are only using weeds, and no comfrey or banana stems,

you may need to add a little water, to just cover the compressed plant material.

Place it in a sunny position and two weeks later check to see if the leaves have turned black. If you tilt

the container you should find a black juice. This is the concentrated plant liquid manure.

This liquid is very strong and should be diluted as follows:

Seedlings: 1 tin of liquid manure for every 4 tins of water.

Bigger plants: 1 tin of liquid manure to 2 tins water. If you make the mixture too strong it can

burn the leaves of plants.

Every two weeks pour the mixture on the soil around your plants, after you have watered them. You

should pour at least one tin of this diluted mixture around each seedling or plant. The tin should be the

size of a big jam tin.

3.How to make a foliar spray

This is brew made from a mixture of plant and animal material. It is used by spraying onto the leaves

of plants from where it is absorbed. This brew contains antibiotics, microbes and plant hormones as

well as plant nutrients (potassium, phosphate and trace elements). (from :EMBRAPA; Brazilian

Agriculture Research Institute)

Place the following ingredients in a container with a lid:

30kg of fresh cow manure

50-60liters of water

5litres of milk (without salt)

5liters of sugar cane juice/ 15kg of chopped sugar cane/2kg of brown sugar (personal

variation)

4kg of wood ash (not coal ash!!)

4kg crushed bones or bone meal (fish bones are ideal if available. If possible do not use

chicken bones) (We use bone meal bought from a gardening shop)

3-5x 20l buckets of chopped weeds

2-3kg of agricultural lime/ crushed eggshells

Leave this mixture for 10-15 days. Dilute 2-10litres of this mixture in 100 liters of water.

This spray is highly effective. It is possible to keep the brew going for a period of time, by adding more

weeds and manure and fermenting the mixture again for about 10 days.

Advantages and disadvantages of foliar sprays

Advantages

Disadvantages

Foliar sprays are very effective and act quickly

in the plants.

If diluted properly, these foliar sprays do not

harm plants

Foliar sprays increase disease resistance in

crops

Foliar sprays provide a quick and cheap plant

booster food

Plant hormones and antibiotics are also

supplied through the fermentation process in

the making of foliar sprays

Some inputs for foliar sprays need to be

bought; such as agricultural lime and potentially

wood ash, sugar and milk

This mixture is exceptionally smelly while it is

fermenting

Foliar sprays can “burn” plants if they are too

strong

4.GOOD PLANTS FOR LIQUID MANURES

Comfrey

This plant has large hairy leaves and grows in wet shady places. The leaves contain a lot of

potassium. These can be used to mulch your vegetable beds and also to make liquid feeds for your

plants Comfrey is also a good spinach and medicine. A tea made from the leaves is good for high

blood pressure and arthritis.

ComfreyFrom: Useful Plants for Land

Design,Pelum

A brew made from comfrey leaves can be diluted

as mentioned above and sprayed on plant leaves

to protect against downy and powdery mildew.

Mildews are a problem mainly on cucurbits,

pumpkins and peas.

A brew made from comfrey and stinging nettle can

be sprayed on plants to protect against early and

late blight, which attacks tomatoes and potatoes.

In these cases, the brews are sprayed onto the

leaves of the plants.

1.Stinging nettle

This is one of the best plants you can use in plant brews. It contains a wide variety of nutrients and

trace elements and is a well-balanced plant food. It is best to collect these plants in the natural forests

where they occur and plant a few in your garden. They do not survive frost, but otherwise grow

almost anywhere.

2.Banana stems

These are chopped up and placed in the container with other plants and leaves. The stems have a

high concentration of potassium and water and make a good liquid base for the brew.

3.Weeds

Black Jack, Amaranths, Chickweed, Galant Soldier. All fast growing weeds, with soft dark green

leaves are good. Avoid using grasses and sedges.

Advantages and disadvantages of plant brews

Advantages

Disadvantages

Plant brews are easy to prepare and use

If diluted these brews do not harm plants

Plant brews increase disease resistance in crops

Plant brews provide a quick and cheap plant booster food.

Plant brews provide mainly potassium, phosphorus and trace

elements.

Nitrogen can be provided if the brew is used early in the

fermentation cycle (after 1 week) and care is taken to avoid it’s

evaporation by keeping the containers closed and cool

Plants drink their nutrients so nutrients immediately available,

easy quick method.

These teas are excellent to use on newly transplanted

seedlings to help them recover from transplanting shock.

Useful method for rainy season when there is lots of leaching.

You can prepare fertilizer teas from animal manure, plant trees

from parts of plants.

Resources such as containers with

lids are required

Plant brews can burn plants if they

are too strong

Effects of the brews on plant

growth are only visible after 3-5

days.

It is not possible to know exactly

which nutrients these brews

contain.

Some people do not like the smell

of these brews, which can smell

very rotten

Nitrogen is volatile and is lost from

the brews quite early in the

fermentation cycle

5.HOW TO MAKE LIQUID MANURE FROM ANIMAL MANURE

Manure can be used from chickens, rabbits, cows, goats and sheep. A mixture of manures is best.

Put your fresh manure mixture into an orange packet and tie the top of the bag.

Put the bag in the container and attach it to a stick or a rope. Then fill the container with water. For

every 1kilogram of manure you will need 5 liters of water. This means an orange sack full of manure

in a large bucket (50l), or half the bag in a normal sized household bucket (20l). This is a way of

keeping the manure and the water separate, because you should not put the wet manure on your

plants.

Cover the container with a lid. Stir every few days.

After two weeks the mixture will be ready to be used. It should look like weak tea. Before using the

liquid, stir the mixture well.

This liquid will be very strong and

should be diluted:

Seedlings: 1 tin of liquid to 8 tons of

water (or buckets or bottles)

Bigger plants: 1 tin liquid to 4 tins of

water

If you make the mixture too strong it

can burn the leaves of plants.

Every two weeks pour the mixture on

the soil around your plants, after you

have watered them. Again, use at

least one big jam tin full for each

seedling or plant. Avoid applying

your mixture in the middle of the day

or on very hot days.

6.Good sources for animal liquid manures

Kraal manure (cattle)

Either use fresh manure or use manure that has been collected in a kraal. In this way you can ensure

that the manure contains as many nutrients as possible and that the nutrients have not been lost into

the air through baking in the sun and drying out. This is especially important if you need your liquid

manure to contain some Nitrogen.

Chicken manure

With chicken manure it is important to collect the droppings while

they are fresh. Again this keeps the nitrogen and other plant food

concentrated in the dry droppings. It is possible to collect the

droppings daily and keep them in a sack in a cool dark place, until

you have enough to make a brew.

Liquid manure made from chicken manure can burn plants, as it can

contain a high level of Nitrogen. It is important to dilute this brew properly before use. If you are

unsure, test the brew on a few plants only and come back the next day. If the edges of the leaves

have gone brown and crinkly overnight, the brew is too strong and has “burnt” your plants.

Goat manure

This is very mild manure and is well balanced. It is unlikely to “burn” plants, but may also be a little

low in phosphorus, depending on the diet of the goats.

Plastic cover

Stick to stir

Sack with ± 40 kg

manure and/or plants

200 litre drum

filled with water

Nutrients

dissolve into

water

Other manures

Manure from rabbits can also be safely used. It is suggested not to use the manure from pigs, due to

the possibility of carrying worm eggs that can infect people. Do not use manure from dogs and cats

for the same reason.

Urine

Human urine is an excellent garden tonic. Urine (from healthy people who are not on medication) is

collected, diluted and watered onto the soil around plants. Like plant based liquid manure, it should be

diluted to a weak tea colour. Avoid using it in the same place regularly.

Advantages and disadvantages of animal liquid manures

Advantages

Disadvantages

Liquid manures are easy to prepare and

use

If diluted properly, these liquid manures do

not harm plants

Liquid manures increase disease resistance

in crops

Liquid manures provide a quick and cheap

plant booster food

Liquid manures provide mainly potassium,

phosphorus and trace elements.

Nitrogen can be provided if the liquid

manure is used early in the fermentation

cycle (after 1 week) and care is taken to

avoid it’s evaporation by keeping the

containers closed and cool

The liquid manure is only as good as the manure of

origin. If the animals are suffering from deficiencies

these will be transferred into the manures. As an

example, there is likely to be a lack of phosphorus in

cattle manure, where cattle have only been grazed

on veld. This means the liquid manure made from

this source will also lack phosphorus.

Liquid manures are generally low in nitrogen. Using

chicken manure drastically increases the nitrogen

content.

The source manures have to be handled well to

retain their nutrients before using as liquid manures.

Effects of the liquid manures on plant growth are

only visible after 3-5 days.

It is not possible to know exactly which nutrients

these brews contain.

Some people do not like the smell of these liquid

manures, which can smell very rotten

Agroforestry Leaf tea Recipe

This is an excellent nitrogen boosting liquid manure.Collect fresh leaves from trees such as

Leucaena, thorn trees and wattle. Put about 30-40kg in a sack and tie securely. Suspend the sack

from a stick across the top of a 200l drum filled with water. Cover the drum with a lid. Stir every 2-3

days by moving the stick gently up and down. This will release the nutrients into the water. Soak the

leaves for about 2 weeks and be sure the sack is kept underwater the whole time. Remove the sack

of leaves (add the leaves to the compost or use as a mulch) then dilute the tea by mixing 4parts of

water with one part of the tea. It should look like weak tea. Apply by pouring it on to the soil around

the plants or sprinkling over the leaves of plants.

4.3 MANURE AS A NATURAL FERTILIZER

Manure is an excellent fertilizer containing nitrogen, phosphorus, potassium and other nutrients. It

also adds organic matter to the soil which may improve soil structure, aeration, soil moisture-holding

capacity, and water infiltration.

Nutrient content of manure varies depending on source, moisture content, storage, and handling

methods. The management of manure can also affect its value. For example; nitrogen is present in

manure and gradually converts to ammonium and nitrate nitrogen. The ammonium form can be lost to

the air if not contained and the nitrates can be leached by rainfall.

Table : Nutrient availability in different types of manure

Nitrogen

Phosphorus

Potassium

Calcium

Magnesium

Organic

matter

Moisture

content

(N)

(P2O5)

(K2O)

(Ca)

(Mg)

FRESH

MANURE

Cattle

0.5

0.3

0.5

0.3

0.1

16.7

81.3

Sheep

0.9

0.5

0.8

0.2

0.3

30.7

64.8

Poultry

0.9

0.5

0.8

0.4

30.7

64.8

Horse

0.5

0.3

0.6

0.3

0.12

7.0

68.8

Swine

0.6

0.5

0.4

0.2

0.03

15.5

77.6

TREATED

DRIED MANURE

Cattle

2.0

1.5

2.2

2.9

0.7

69.9

7.9

Sheep

1.9

1.4

2.9

3.3

0.8

53.9

11.4

Poultry

4.5

2.7

1.4

2.9

0.6

58.6

9.2

Advantages and disadvantages of using manure

Advantages

Disadvantages

Manure helps to maintain the organic matter

content of the soil, improves soil structure and

water infiltration.

However, manure is quickly decomposed under

warm, moist soil conditions. Composting and

stockpiling manure can reduce the number of

viable weed seeds.

Composting manure increases the nutrient

content and safety for use considerably.

Manure is cheap and readily available in rural

areas.

Weed seeds are common in some manure..

Poultry droppings typically have fewer weed

seeds surviving the digestive processes..

With the manure rates used for most crops,

organic matter content in soil is only temporarily

increased.

Manure can cause a build up of salts in soils

that are already highly saline or very badly

drained.

Fresh manure can burn young plants.

Zinc deficiency can be induced or increased

with repeated high rates of manure, especially

on sandy soils.

5 NATURALPESTANDDISEASECONTROL

5.1 ENEMIES OR FRIENDS

Plants, animals and micro-organisms can influence the productivity in your garden. About 99% of all

plants, animals and microorganisms are beneficial to agriculture and the general economy. It is only

1% of all living creatures that causes so much trouble in gardens around the world. If left undisturbed,

natural enemies could mostly keep this troublesome 1% under control. Modern agriculture techniques

generally do not consider the relationship between organisms, or the balance between different

populations that keep pest explosions in check.

Small scale farmers may attempt to grow crops in poor soils under less than ideal conditions. Plants

stressed in this way are easily susceptible to pest and disease attack.

5.2 PLANTS

Unwanted plants are called weeds. Weeds can cause damage to crops in several ways:

−They take up water and nutrients from the soil, in competition with the crop.

−They can shade crops from the sun. Sunlight is very important for the growth of crop plants.

−They can host insect pests that can damage the crops.

−They can reduce the quality of the produce, e.g. weed seeds found in cotton would reduce the

price considerably.

Weeds aren’t always pests

They can be used to your advantage:

-Weeds can be slashed and used as a green manure to feed the soil.

-They cover the soil and can prevent soil erosion.

-They can attract and host very valuable beneficial insects (predators and parasites).

-They can act as wind breaks.

Animals

Birds

Birds can be divided into two large groups:

the meat-eaters and the plant/seed eaters.

The plant/seed eating birds can damage

your crops by eating the seedlings, fruits

and seeds of the crop. Such birds are:

crows, sparrows, pigeons and finches.

Not all birds are pests

The meat-eating birds can be very beneficial in your lands, as they will reduce the numbers of insects

and rodents in the crops. Such birds are owls, swallows and hawks.

Slugs and snails

These creatures can cause considerable

damage to your crops if they are not

controlled.

Insect Pests

Insect pests can be divided into two

categories:

Sap-sucking pests

Examples are aphids, scale insects, mealy

bugs, leaf and plant hoppers, whiteflies, thrips,

mites and red spider mites.

Plant-eating/chewing pests

Examples are caterpillars (armyworms, leaf-miners,

cutworms), beetles, locusts and crickets.

➢Not all insects are pests

Some insects are beneficial to your crops, such as:

−Bees that pollinate crops,

−Predators that feed on insect pests (e.g. wasps)

and

−Insects that help to decompose organic material

(e.g. dung beetles).

Nematodes

Nematodes are very small worms that can hardly be seen

with the naked eye. These tiny worm-like creatures feed

mainly on the roots of plants. At first the damage will not

be noticed, but as the numbers of these little creatures

increase, the plants will decline and could eventually die.

➢Not all nematodes are harmful to plants.

Only a small percentage of nematodes are plant eaters, the

rest live on organic material in the soil or feed on small

animals in the soil.

5.Micro-organisms

Micro-organisms are tiny creatures that can usually not be

observed with the naked eye. They can, however, be seen

when they occur in large numbers. Micro-organisms are

responsible for diseases and can be classified as fungi,

bacteria and viruses.

Fungi

There are quite a variety of fungi that can influence

our lives. Fungi that cause plant diseases are

usually tiny parasitic organisms that grow on or

inside plants. A mass of these usually consists of

tiny threads (called hyphae), which infect the cells

of the plant. Fungal spores can disperse through

the air or with water or with the help of other

organisms and cause new infections. They can lie

dormant in the soil for several years, as sporing

structures. Most fungi prefer moist, warm weather.

Fungi can be devastating in a crop. Fungi cause

diseases such as blights, mildews, and certain root

rots.

Fungi are not always disease causing.

Some fungi are very useful and even crucial for life

on earth. Some of these fungi are bigger and can be

seen with the naked eye. For example the

mushrooms and bracket fungi that are found on

fallen trees. These fungi help with the decomposition

of the wood and the nutrients in the wood are made

available to other organisms. Other fungi are used by

ants and other small insects as a food source

Bacteria

Bacterial diseases are caused by minute

organisms that reproduce rapidly by

division. Bacterial diseases in plants are

difficult to cure. The best way to prevent

serious damage is to destroy affected

plants. Bacteria cause diseases such as

soft rots and some leaf spots.

Viruses

Viruses are amongst the smallest of all

living organisms. They cannot be seen with

the naked eye. Only the symptoms can be seen on the plants. Viruses cannot reproduce without the

help of another organism. They also need

a vector to infect a plant. Many sap-sucking

insects act as vectors. Generally there are

no cures for virus diseases and affected

plants should be destroyed.

➢Not all micro-organisms are

pests

Many species of micro-organisms can help

plants by feeding them. Such beneficial

micro-organisms are encouraged by

healthy soils.

5.3 DIAGNOSING PLANT PROBLEMS

Before symptoms can be treated it is important to have an idea of the

cause of the problem. Damage to plants can be caused by insects,

animals, micro-organisms, natural causes (such as drought and

nutritional disorders), or by chemical injury.

It is not always easy to identify the cause of a problem immediately from visual symptoms. There are

hundreds of causes of plant problems and two or more of the causes might produce the same

symptoms. A single visual symptom can also be caused by a number of different problems.

Identification of the cause of a particular symptom requires years of experience, but guidelines can be

given to make it easier.

Ways to identify insect damage

SYMPTOMS

CAUSE

Ragged leaves, holes in wood, fruit or seed.

Mining on leaves. Wilted or dead plants. The

presence of larvae

Chewing insects

Foliage and fruit are off-colour and sometimes a bit

distorted

Sucking insects removing sap and cell

contents from the plant and injecting toxins

into the plant

Black sooty substance covering the leaves, twigs,

branches and fruit. The sooty cover can easily be

removed by rubbing the leaves.

Honeydew excreted by certain insects leads

to the growth of sooty mould. Leaves

suffocate and plants do not grow well.

Galls on leaves, twigs, buds and roots

Gall forming insects

Scars on stems, twigs, bark and fruit. Fruit is

sometimes infested with larvae

Insects laying their eggs in or on the plants.

Ways to identify disease damage

SYMPTOMS

CAUSE

Wilting, root rots and stunting

Clogging of water-conducting cells of the plant

Blotching, scab, black spots on leaves

Destruction of the chlorophyll in the leaves

The symptoms of

diseases are often

similar to nutrient

deficiencies and can

easily be confused.

It is important to

note that the

following are

rough

guidelines

Unusual growths on flowers, twigs and roots

Gall forming bacteria that disrupt normal

cellular organization

Flower and seed rots

Fire blight and bacterial rots

Wilting, dwarfing and off-coloured foliage, usually

patchy in appearance, leaves become distorted

Viral diseases carried from one plant to

another by aphids and other sap sucking

insects

Soft rotting of fruit, foul smelling.

Bacterial soft rots; usually in a wet

environment

5.4 BIO-INDICATORS

Pests and diseases can be helpful in a way too. When these are spotted in the garden, they are

indicators that something is wrong. In order to fix the problem, you need to know what the indicator is

telling you. By just killing off the pests and diseases with chemicals, you will never fix the problem.

The solution would be to make the plant and its environment healthy enough to fix itself. Healthy

plants have a natural resistance against pests and diseases.

Weeds can also be used as bio indicators. They can tell us a lot about the soil

they are growing in. Weeds with very strong taproots indicate soil compaction.

The weeds grow there to break up the soil and improve the soil structure. Ferns

and Oxalis indicate acidic soils, while nutgrass and sedges indicate that there is

not enough air in the soil, because of compaction or water logging. Amaranthus

(shown alongside) indicates fertile soil with bad structure, but very rich in

nitrogen.. Weeds also take up minerals from the soil and keep them from

washing away or leaching into the soil. Blackjack has the ability to take up

nutrients that are not available to crop plants. If you take out the weeds from

your land and bum them or just throw them out, you are losing vital minerals. Try

to incorporate them back into the soil, so that the minerals can be used by your

crops.

5.5 BIOLOGICAL PEST CONTROL

Beneficial insects

A relatively small number of insects can be regarded as pests.

The majority of insects are harmless or do insignificant damage

to crops.

Some insects are beneficial to the farmer in various ways. It is

important to encourage the activities of these beneficial insects.

The beneficial insects can be divided into three major

categories:

−Natural enemies

Many insects eat other insects that are possible pests of crops. In

this way the numbers of the pest insects are kept down.

These insects include:

Dragonflies - Feed on insects and worms.

Mantids- Feed on insects.

Ground beetles - Some species feed on aphids and caterpillars,

snails, fly larvae, eggs or pupae, white others are vegetarian,

living on seeds or green plants.

Ladybirds - Feed on aphids, leafhoppers, plant hoppers, scale

insects and mites.

Lacewings - The adults and the larvae prey upon many pest

species such as: plant hoppers, leafhoppers, aphids, scale

insects, larvae of moths and mites.

Ant-lions - Feed on small crawling insects trapped in their pits.

Maggots of hover flies - Feed on aphids. The flies feed on

pollen and nectar.

Robber flies - Feed on small flying insects and small

grasshoppers.

Parasitic wasps- Parasites of pest species like caterpillars.

They can also parasitise the eggs of pest species.

Advantages of biological control

−The agent targets the pest species and are non-toxic to

other species and to human beings.

−Once the population of biological control agents are

established, it normally retains itself.

Robber fly

Lady bird

Dragonfliy

Praying mantid

Lacewing

−The development of genetic resistance is minimised,

because the pest and the predator develops together.

Disadvantages of biological control

−Biological agents are slow to react. You will not get

immediate protection from pests.

−Predators will have to be protected from pesticides

sprayed elsewhere, because most pesticides kill all

insects.

Pollinators

Bees are the main pollinators, but insects like butterflies, moths,

several fly species and some wasps can also assist in the

pollination process.

Scavengers

Some insects live on dead organic material and help in the

breakdown of plant debris in compost heaps and in gardens.

Animal wastes and dead animal tissue are also broken down in

this manner, e.g. dung beetles.

6.Encouraging predators

It is important to recognize other predators of insects as well.

The encouragement of predators can help control pests and

diseases. A soil with a good structure can host a number of

beneficial soil organisms.

Birds - Some birds feed on insects and can help in protecting

your crop. Seed-eating birds will damage your crop.

Chickens feed on insects, but can damage seedlings.

Geese are used for weeding of orchards. They will eat fruit that

has dropped from the trees, preventing them from rotting and

contaminating other fruit.

Hover fly

Parasitic wasp

Bee

Diadem butterfly

Chameleon

Chameleons - Feed on insects that can damage your crops.

Lizards - Predators of insects.

Frogs are good for controlling insect pests.

Snakes eat rodents and insects.

Spiders eat insects. The majority of spiders are harmless to

human beings and they can be very helpful in keeping pests

away.

Physical control methods

This is the use of physical methods to prevent

or control the outbreak of pests or diseases.

Physical control methods include barriers,

traps and artificial guards. Some physical

crop protection methods are still in use, but

are mostly not regarded as important. Fly

traps and sticky yellow insect traps are

commonly used and very effective.

Right: A home made fly and fruit fly trap and

Far right; a sticky yellow insect trap.

Protective borders and barriers

Set up boards about 10cm high around your crop and paint them with fuel or oil, or

use bands made of cloth or board on larger stems or trees. These boards or

bands will discourage crawling insects from getting into the crop.

A tin can open at bothends, or toilet roll centers, can be placed over seedlings as

collars to keep cutworms away from the seedlings. They should be pushed firmly

into the soil (Shown alongside).

Traps

−Snail and slug traps

−Stale beer in a shallow plate or container, dug into the

ground. The slug or snail will crawl into the liquid and

drown. Other liquids containing yeast will also act as

baits.

Spider

−An inverted cabbage leaf placed on the ground will attract

snails, slugs, cutworms and other pests that hide during

the day and forage at night.

Right: A beer trap for snails and slugs.

Ants can be lured into containers baited with sugar water, fats or

any other food residue.

Grasshoppers are attracted by all kinds of scents: citrus fruit,

lemon or vanilla extracts, beer, vinegar, salt, soap and smoke.

Cockroaches can be trapped by greasing the inner neck of a

bottle baited with a raw potato or stale beer.

Some flying insects can be attracted by light. Red, orange and yellow lights are avoided or ignored

by almost all insects.

Aphids, wasps and all kind of flies are attracted to the colour yellow. A

trap can be made with a shallow yellow-painted bowl, filled with soapy

water.

Many insects are attracted to different colours. Try experimenting with

different colours. The collected pests can provide food for fish and

chickens.

Rodents can be trapped in several ways. It is important to place the traps

in the regular paths of the rodents, and they must be attractive to the

rodents, so that they will investigate and not avoid the trap.

Rodents can be trapped and drowned when a large bucket is dug into the

soil and almost filled with water. About 3 cm below the top edge a line of

peanut butter is smeared. The animals fall into the trap and drown when

trying to eat the peanut butter.

Artificial guards

Black cotton threads can be used to scare birds away from crops. The threads

should be spread wide and loosely between the branches of fruit trees or around

crops. The birds will fly into the threads and be scared away, without being

trapped.

Scarecrows, cans and aluminium foil strips on strings,, as well as old cds’ can be

very effective in scaring birds and other animals away shown alongside). Care

should be taken to move them on a regular basis so that the animals don’t

get used to them.

Rodents and seed-eating birds can be scared by cutting out cardboard

silhouettes of owls or other birds of prey and suspending them over the

ground by attaching them to a rope and on top of a high pole. The shadow

is cast on the ground and is mistaken for the real thing (shown alongside).

Other physical control methods

Burning of infected plant material, ploughing back, etc., can be regarded as

physical control.

Pupated maize stalk borers can be destroyed by

making animal feed or fuel out of the maize stalks.

Stored beans can be protected by storing them in

sand.

Weeds should be slashed before they flower to

reduce reproduction by seeds.

Ants can be controlled by constantly destroying

their nests and re-mixing the soil.

Botanical remedies

Spraying with herbal poisons or plant teas can

control pests and diseases to a large extent. Some

of the most widely used insecticides originally

came from plants. The flowers, leaves, or roots

have been finely ground and used in this form, or

the toxic ingredients have been extracted and used

alone or in mixtures with other toxicants. The

active chemical from the plant was then identified

and reproduced as a synthetic chemical in the

laboratory and sold as a chemical. These synthetic

chemicals have the same properties as the natural

chemicals but do not break down as easily as the

natural chemicals and can thus damage the

environment.

Another advantage of natural or organic remedies

is that they are cheap. But it must be realized

that some organic remedies are as poisonous as some chemicals and that some chemicals are

less poisonous than some of the organic remedies.

Many plants with control possibilities are known and probably many others are yet to be discovered.

Leaves of many strong-smelling, bitter-tasting plants like gums, lantana, khaki weed, tomato or any

other herbs have great potential for insect sprays. Plants that do not get attacked while in among

affected plants are also potential remedies.

Hot water seed treatment to eliminate seed borne

diseases

Seed can be treated using the following process:

- Place 250g of seed in a cotton back

-Soak the seed for 30 seconds in cold water and for

20 minutes in water heated to and maintained at

50°C (just too hot to touch)

-Cool the seed in fresh cold water

-Spread immediately in the shade to dry

Most plant material such as bulbs, rhizomes, tubers

and cuttings can be treated in this way to reduce or

eliminate disease.

General points regarding aromatic plant sprays

Sprays can be made up from the chopped up leaves of different strong smelling plants. Plants like garlic,

chilli and onion work well.

The sprays have to be re-applied after rain or irrigation as they are washed off with water

Green bar soap can be added to make the spray stick to the plants and the insects

Generally the sprays are made up in 1 liter of water. They are diluted from there; 1 part solution to four

parts water before being applied

Most botanical insecticides are contact poisons. Spraying has to be done rather intensively to ensure all

insects have been covered by the spray.

Sunlight breaks down the sprays, so they should be prepared and stored out of direct sunlight

Some crops are damaged by sap from other plants and it is possible for some of these remedies to ‘burn’

the leaves of plants they are applied to. Always test a new remedy on a small number of plants first

For most applications against insects the best time of day to spray is in the late afternoon

6 MIXEDCROPPING

Diversity in our gardens is important for family nutrition and for continuity. We also want to create as

much diversity n pour gardens as possible to ensure a natural balance in the garden. We want to

create a living soil, use water efficiently and minimize pest and disease attack on our crops.

To attain mixed cropping, corps can either be inter-planted (different crops in the same bed at the

same time), or crops can be rotated (different crops are planted in the same place at different times).

Using both practices in your garden is a good idea.

6.1 INTER-PLANTING

When planting a number of different crops together we need to consider the following:

•Nutrient consumption: We mix crops together that consume different amounts of nutrients.

Some plants are heavy feeders and need a lot of nutrients. Other plants are light feeders and

some even add nitrogen to the soil. A good example is the traditional practice of planting

maize and beans together. Maize is a heavy feeder, while beans are light feeders as well as

fixing nitrogen in the soil.

•Root depth: Plant deep and shallow rooted plants together to ensure that they do not compete

for nutrients and water. A good example is planting maize and pumpkins together. Maize is an

upright plant that has a deep rooting system and pumpkin is a creeping plant with a shallow

rooting system. They do not compete for space either below or above the ground.

•Insect repellent plants: There are some crops which have a unique smell that repels some

kinds of insects. For example, onion has a specific smell that butterflies dislike. If onions are

inter planted with cabbage, this will reduce the attack from insects (worms). Combinations like

onion and cabbage are called companion plants. Companion planting is an effective pest

prevention measure.

•Timing: Some crops have a longer life cycle than others. It is possible to plant crops that

mature quickly in-between crops that take longer to mature. In this way one crop can be

harvested while the other crop is still growing and competition is reduced. An example is

planting radish, mustard spinach and potatoes together. Radish matures quickly and is

harvested within 6 weeks of planting. The leaves of the mustard spinach are harvested for 2-3

months. This reduces competition with the potato plants that are now growing large. Potatoes

are harvested after 3.5-4 months. A combination such as this also includes that aspect of

rooting depth, nutrient consumption and insect repellent properties.

•Shade tolerance: This becomes important when tall crops and perennial plants are also

grown in the garden. These include fruit trees. Some crops such as comfrey, lettuce and

strawberries are shade tolerant.

Examples of inter-cropping in a vegetable garden

The following combinations work well together in the same bed:

Plant carrots and onions together: Carrots protect against onion fly and onions protect against carrot

fly. Carrots root more deeply than onions and are harvested earlier; giving the onions the space they

need to mature.

Plant cauliflower or cabbage, lettuce, fennel and onion together: This combination

gives complete control of aphids and diamondback moth (shown on the right) on the

cauliflower. It takes into account nutrient consumption, rooting depth, insect repellent

properties (onion and fennel), timing and shade tolerance.

Plant tomatoes, onion or garlic and carrots together: This combines insect repellent properties,

nutrient consumption, rooting depth, timing and disease control. Tomato plants are scattered so that

they do not touch each other, which reduces the incidence of early and late blight.

Plant swiss chard (spinach) and beans together: this combination takes into account nutrient

consumption, rooting depth and disease control on the chard. Planting the chard in alternate rows

with beans reduces the incidence of bacterial spot on the chard.

Many different combinations are possible. Below are two more examples:

Left: Swiss chard inter-

planted with fennel and

garlic chives

Right: A bed with

onions, cabbage, lettuce

and swiss chard planted

together.

There are a number of crops that grow well together and some that do not. When planting a bed, use

the diagrams below to choose combinations of crops that suite each other.

Some plants which grow well together:

Beetroot- onions

Carrots- peas, lettuce, onions, tomatoes

Onions - beetroot, strawberries, tomatoes, lettuce

Eggplant - beans

Cabbage - potatoes, beetroot, onions

Green Pepper- all vegetables

Lettuce - carrots, radishes, strawberries, cucumbers

Pumpkin - mealies

Swiss Chard - strawberries

Tomatoes- onions, carrots

Mealies - peanuts, peas, beans, cucumber, pumpkins, potatoes

Sunflowers - cucumbers

Beans - potatoes, carrots, cabbage, most other vegetables

Plants that do not grow well together:

There are some plants which do not grow well together. Try to avoid putting them in the same beds.

Try and experiment for yourself.

Beetroot- pole beans

Onion - peas and beans

Cabbage - strawberries

Pumpkin - potatoes

Tomatoes- potatoes and cabbage

Beans - onions

Sunflowers - potatoes

Advantages and disadvantages of inter-planting

Advantages

Disadvantages

Efficient use of space below and above ground

Looks “untidy”

Reduces and avoids pest and disease build-up

in the soil and in the garden

Can make harvesting of crops more time-

consuming

Reduces weeds. Covers the soil and uses

nutrients in an effective manner. Building of a

healthy, living soil is possible.

Weeding can be more time consuming initially,

as crops may be scattered, rather than being

planted in rows

Plants support each other in a synergistic

relationship that protects against pest and

disease attack and increases vigour and growth

Some shading may occur if plants are not

spaced well

Efficient use of water

Some plants may be over or under watered

depending on their life cycle. For example, some

plants may be seeding while others are still

growing.

6.2 CROP ROTATION

The same crops are not planted in the same areas, fields or beds season after season. Different

crops are planted in a 2-4 year rotation. These crops are chosen to have a mutually beneficial effect.

Effects of crop rotation

It prevents or stops the accumulation of insects and diseases. If the same crop is planted some

insects and diseases will become more every year!

•Different crops use different nutrients or plant food stored in the soil. In this way you do not

overuse some of the plant foods, while not using others.

•The soil can be covered all year round.

•Some crops add nutrients or nitrogen to the soil. Examples are beans, peas, broad beans,

soya beans, peanuts, cowpeas, lucerne and clover.

•It prevents the soil from building up bad or negative

reactions to specific plants. An example here is

nematodes on tomatoes and swiss chard.

Nematodes are very small worms that we cannot

see with our eyes. They live in the soil and feed on

the roots of your plants.

•There is no buildup of specific weeds.

There are a number of different crop rotation systems that

can be used. Below is an example of a system that is easy

to use and remember.

A 3 year rotation for vegetable and field crops:In the first

season after applying compost and or manure heavy

feeders or nitrogen consumers are planted.

In the second season light feeders are planted and

In the third season legumes are planted. This is followed by

another application of compost or manure and the cycle is repeated.

In trench beds, where the organic matter is decaying slowly in the soil, you may want to start with

legumes, move on to heavy feeders or nitrogen consumers and then move on to light feeders. This is

because during the decaying process plant nutrients will take a while to become available for use by

plants. The legumes can fix most of their own nitrogen and are thus a better starting point.

Preparing the bed well:

This would mean trenching, or

double digging or addition of a lot

of compost/manure forked into the

top 40cm of soil. You will need at

least 4 full spades for every

square meter.

A general recommendation is to

place 30 tons of compost to a

hectare of land. This comes to

about one half of a wheelbarrow

load for every square meter (which

is about the same as 4 full

spades!)

A 4 year rotation for vegetables.

Nitrogen fixers

E.g.: Beans, broad

beans, soyabeans,

peas, cowpeas,

lucerne, vetch

Light feeders

Examples: beetroot,

carrots, parsnips,

onions, leeks

Heavy feeders

Examples: Potato,

maize, pumpkin,

tomato

Nitrogen consumers

Examples: cabbage,

cauliflower, broccoli and

mustard

Prepare the land or bed well. Put a lot of compost or manure in your bed (4 full spades/ square

meter). Then:

Start by planting a fruiting crop. These plants need the most food.

Leaf crops need less and can follow fruit crops.

Then root crops can follow leaf crops without much addition of plant food. Root crops like fertile soil,

but do not like fresh manure or compost. It has to be well rotted.

Then, nitrogen fixers can follow, with addition of little or no plant food. Then you need to prepare the

land well again. Start once more with fruiting crops.

Advantages and disadvantages of crop rotation

Advantages

Disadvantages

No build up of pest and diseases

Soil nutrients are used effectively

Soil moisture is used effectively

A healthy living soil can be built up over time

Without a plan, either drawn or written on paper,

it is difficult to remember which crop is to follow

It can be tricky to decide which rotation to follow

when inter-planting is also used