Wetar – Indonesia Aug 22nd Mon
Profitable and Sustainable Agricultural Production in lowlands of Eastern Indonesia
‘Food Always in the Home’
Dave Askin
August 2011
Trainee WorkbookTable of Contents
1 Introduction – pictures tell their own story 3
2 Growing a productive and profitable ‘FAITH’ garden 4
2.1 The role of climate – sunshine and water 5
2.2 Water – crucial for life 5
2.3 Soils - garden productivity and sustainability 8
2.4 Soil organic matter 11
2.5 Soil is precious- control erosion 13
2.6 Mulch 15
2.7 Green manure legumes help restore soil fertility 22
2.8 Integrate and control animals effectively 27
2.9 Grow more trees 33
2.10 Grow great fruit trees 35
2.11 Using Fertilizers bought from stores 37
2.12 Calculating amount of fertiliser from the store to use on a plot 41
2.13 Banding fertiliser 42
3 Management and an Action Plan 43
222 Mulch has many benefits
1 Introduction – pictures tell their own story
This manual will guide you with the following images.
Things to discuss? / Questions to consider
Issues to think about/Lessons to learn
P / A walk – take a look at something
Working together on an experiment or task linked to our learning
ý / Learning from those in other places
~ / Danger - beware
2 Growing a productive and profitable ‘FAITH’ garden
FAITH stands for ‘Food Aways in the Home’ garden. Farmers everywhere want profitable, sustainable gardens that produce healthy food for their family and a surplus to sell.
Seven principles for success are outlined along in the diagram below.
Ø Sunshine is the driving force behind soil fertility. Is the sun growing useful plants or just hitting bare soil?
Ø Water is a precious resource- and needs to be managed carefully- coping with too much and too little.
Ø Soil is precious – maintain high levels of organic matter and don’t lose the soil through erosion.
Ø Mulch has many benefits – organic matter is a foundation for soil fertility.
Ø Green manure legumes provide many benefits.
Ø Animals can provide many benefits, but need integrating in a garden.
Ø Trees of many kinds add value.
Figure 1 Keys to successful FAITH gardens, with sunshine and water providing crucially important inputs.
2.1 The role of climate – sunshine and water
Garden productivity is dominated by factors both in and out of a farmer’s control. The first is climate and is mostly out of the control of a farmer. Climates in the tropics tend to fit under two broad headings.
Ø Warm and wet all the time or
Ø Warm and wet for some of the time, while the rest of the year experiences a long dry season.
Ø The sun provides the energy for life on earth.
Ø Plants use the energy from the sun, and turn carbon dioxide gas into green leaves and vegetables, fruit, timber etc. These die and rot creating valuable organic matter.
Ø Don’t waste sunshine by having sunshine hitting bare ground.
Ø Sunshine is your source of income and your renewable fuel.
Ø In a rice paddy there are times when the soil is bare to allow for cultivation and planting seedlings. This is good.
2.2 Water – crucial for life
Water is absolutely crucial to all of life. There is a close correlation between hunger, poverty, and water. Most hungry and / poor people live in areas where drought is common. In many parts of the tropics it is either too wet or too dry. What can we do about this?
Too much and too little rain cause big problems
Ø Too little rain and plants can’t grow. There is also an increased risk of fire damaging a garden or houses. Farmers must also work hard to water crops.
Simple rain shelters in Java, increase crop profitability during wet season.Ø Too much rain is also a challenge. Plants don’t get enough sun during cloudy weather. This means disease and insect pests cause many problems. Plants may rot and die. Pollination may fail, meaning fruit set will be reduced.
Ø Unpredictable seasons are a challenge for farmers. Longer than normal wet or dry seasons make planning and crop scheduling very difficult.
Wet season – too much rain
Ø Nutrients are washed away in heavy rain
Ø Top soil is lost during heavy rain
Ø Roots may rot in soil that is too wet
Ø Plants collapse with disease as they have too little sun to allow them to grow in a healthy manner.
Ø Sometimes we must protect sensitive plants by using plastic covers.
Ø Choose to grow plants that cope with lots of rain – eg Kangkung.
Dry season - Coping with drought – hand water pumps
The long dry season on Pulau Wetar means farmers must irrigate – using wells- either hand lifting water in buckets or making use of petrol/diesel pumps or hand operated pumps.
Key issues with pumps and indeed all outside technologies include construction costs, repair costs and problems with maintenance and of course running cost. Tee pumps are used - refer below
This is one of the two wooden foot valves with heavy rubber that allows water to flow up through it, by suction, but does not allow water to flow down because the heavy rubber flap closes.If the flap is made of soft inner tubing, it will collapse under the weight of water pushing down on it.
Ø Mulch will help to reduce the problems of a long dry season, making any water applied more effective. Mulch and organic matter increase the water holding capacity of a soil, which will also assist in increasing growth of crops, when water is limited.
Ø Drip lines are used by some farmers to increase the effectiveness of water applied. Cost may be prohibitive.
2.3 Soils - garden productivity and sustainability[1]
Introduction
Crop yield is based on soil fertility. Year after year, a farmer wants their gardens to keep producing healthy crops. Productivity and sustainability are largely controlled by soil management. This manual will develop improved soil management skills for each willing farmer.
The best soils have à
Ø Good drainage,
Ø Deep rooting zone,
Ø Easy movement of air, water and roots,
Ø Balanced nutrient supply,
Ø Good organic matter content and stable soil structure,
Ø Erosion minimised.
Healthy soils exist under rainforests so our discussion starts with the characteristics of a rainforest and the soils beneath the old forest trees.
Soils and the rainforest
The soil under a rainforest is healthy, full of life and the starting point for a productive garden.
Ø Rainforests protect soil from heavy rain.
Ø Rainforests hold heavy rain, allowing it to move to rivers slowly, reducing the size of floods.
Ø Rainforests protect soil from hot sun.
Ø Village gardens that have features similar to a rainforest will be better than those with bare soil or weeds.
Before we consider management we need to know something about soils.
What is a soil?
Soils are made up of à
Ø Varying amounts of clay, silt and sand.
Ø Microbes -such as fungi, bacteria and many kinds of worms, tiny insects and plants. Many of these are helpful in a soil, but they may be killed when farmers use insecticides (an insecticide is a poison that kills insects)
Ø Air spaces – (there is lots of air in sandy soils and very little air in wet clay soils).
Ø Organic matter - Dead plant material and living and dead microbes. This is sometimes called humus.
Ø Water – amounts vary greatly depending on weather and soil type.
A soil that is made up of just clay will be very sticky in the wet season and is likely to crack badly when dry- see photo. That soil becomes very hard to dig when either too wet or too dry. Add organic matter to this soil to help improve it.
A soil that is very sandy is never too wet or too hard, but it is easily eroded and holds very little moisture. It rapidly dries out after rain. Add organic matter to this soil to improve moisture holding capacity.
Soil profile showing different layers called horizonsHealthy soil is alive, teeming with millions of tiny living organisms and animals. Farmers need to care for these tiny soil creatures, beneficial worms and plants in the same way that you look after your bigger animals such as pigs, buffalo or chickens.
Soils have layers and these are important for village farmers
Explaining soil layers
Soils are arranged in horizontal layers called horizons. These layers are named A, B, and C.
Above the A-horizon - Sometimes called the O horizon
Ø Most nutrients are stored above the A-horizon in tropical soils. In the forest and leaf litter.
Ø When cut and burnt these nutrients behave just like artificial fertiliser- they are very susceptible to rain and erosion.
A-horizon
Ø Surface soil or topsoil which is often 15 to 20 cm deep.
Ø The upper part of the A-horizon is rich with organic matter.
Ø Easily eroded after fire.
The B-horizon
Ø Lower fertility, often with impeded drainage. It may be coarse sand and river gravels.
The C-horizon
Ø This is part of the bedrock from which soil is formed.
It takes many, many years to form a soil. Don’t let the topsoil wash away through poor management.
Assessing soil texture
For at least two kinds of soil (preferably old garden and rainforest soil) -Ø First - assess the amounts of material that can rot (organic matter) in each of the two soils.
Ø Now, place in the palm of your hand about a teaspoon of soil, add some water, (spit works) and rub the soil into a wet paste. Now with your other thumb rub hard on the soil and water mixture.
Ø Does it feel slippery, indicating lots of clay, and an ability to store lots of water?
Ø Or is it rough, with lots of sandy material in it? If so, you have a coarse textured soil which is likely to be well drained. However, during dry spells, your plants are likely to be affected by drought.
Ø If your soil is very finely textured, with lots of clay, the soil is likely to be poorly drained, but may also hold lots of water when wet)
How do plants take up soil nutrients?
Plants take up nutrients from the soup we know as soil solution. This solution is water mixed with nutrients. Nutrients in soil water come from à
Ø rotting plant material,
Ø fertiliser from a store,
Ø added materials like animal manure or ash from fires,
Ø and to a lesser extent the weathering of rocks (parent material) in the soil.
As organic matter rots, nutrients in the leaves and twigs are released. Moisture makes those nutrients available for plant roots to take up. The plants don’t mind where the nutrient comes from – eiither from fertiliser or rotting material BUT the fertiliser from the store doesn’t add any of the physical and living benefits that rotting organic matter provides.
However, rain can often be excessive and storm events cause nutrient loss in two ways.
1. Firstly there is flooding and overland erosion where soil and nutrients are physically washed away in a flood.
2. Secondly, rain can move through the soil to below ground layers and carry with it the fertility that was in soil solution.
Organic matter releases fertility only slowly which is good for plant growth. Chemical fertilisers tend to release nutrients very quickly and they may be lost if there is heavy rain when the plants are small.
So, wherever possible, choose to increase garden yields with organic forms of nutrients such as animal waste and mulch.
2.4 Soil organic matter
Why is soil organic matter important?
Ø It acts like a sponge holding moisture and nutrients for plants,
Ø It keeps the soil open, letting water and air into the soil. (Stops the soil surface sealing over),
Ø It reduces soil cracking,
Ø and it provides fertility for plant growth as it rots. It therefore has a large influence on garden yields.
Soil organic matter is like a battery or bank account
Ø It has taken many years to charge up the organic matter ‘battery’ with plants capturing solar energy (sunshine), growing, dying and rotting.
Ø Its easy to lose but it takes a long time to recharge organic matter in the soil
Ø Soil microbes use soil organic matter as their main food, energy or fuel source.
Ø Take soil from an old garden and soil from under a rainforest.Ø Look for small insects in both
Ø Look at both - feel the difference in both soils. Which would be easier to dig?
Soils without organic matter become hard – especially when dry.
How is organic matter lost?
Ø Hot temperatures, combined with moisture (the conditions on Wetar) allow organic matter to be rotted and lost quickly,
Ø Fire destroys soil organic matter,
Ø Cultivation rapidly depletes soil organic matter levels,
Ø Heavy rain causing erosion.
So, try to always have useful plants / roots growing in the soil, capturing solar energy.
Keep your soil covered- in the way a rainforest covers the soil.Bare soil is ‘degrading’ soil
How does soil organic matter increase?
Ø When plants grow (using sunshine) they accumulate carbon and this is the way organic matter increases.