Worldwide, challenges for subsistence farmers have increased. Harvest production may be down leading to reduced incomes and reduced staples for family consumption. These challenges can be due to depleted soils, lack of funds for purchasing fertilizers, changes in the beginning and end of the rainy season, unpredictable rain during the rainy season, and increased soil erosion and crop damage during extreme weather events.
|Adding Organic Material to Your Soil
|There are simple, low-cost/no-cost activities that subsistence farmers can adopt that can increase harvest production by restoring soil, reducing the need for chemical fertilizers, buffering the effects of variable rainfall, and protect valuable topsoil from erosion—increasing family nutrition and agricultural income.
What Is Soil?
Soil is a living, breathing organism of sand, clay, organic matter, earthworms, microbes, beneficial flora and fauna, nutrients, minerals, water and plant roots. It can suffer from being too wet, too dry and too sandy, too clayey, too exposed and too steep.
Moisture in the soil is a chief determinant in crop growth and in agricultural production both by providing water for the soil, improve soil chemical processes in the soil and also acts as a transport mechanism for getting nutrients to the plants. The presence of organic material greatly improves soil’s ability to retain moisture. Moisture stored in the soil provides a buffer during dry periods or during periods of unpredictable rain. Sufficient organic material in the soil and mulch is on the surface of the soil can help rainwater percolate into the soil in order to build up soil moisture.
Organic material decomposes in the soil and releases vital nutrients for the plants—reducing the need to purchase expensive fertilizer. Increased organic material in the soil also helps to retain soil moisture for longer periods of time—buffering against unpredictable rain or an early end to the rainy season. Organic material in the soil is a benefit for root penetration, drainage, aeration, nutrients nutrient availability, soil structure—and can neutralize pH imbalances.
Looking at organic material samples collected from around the village.
In the first year, farmers may not have organic material. Let them know that they can begin by spreading whatever chopped-up organic material (OM) they can find on top of their field. This can be leaves, manure, chopped-up corn stalks, vegetable-based kitchen scraps. Explain how many freely available types of OM are available around their village; have participants discuss other materials that they might be able to use.
Incorporating Organic Material into Your Soil during Soil Preparation.
Farmers can spread organic material on top of their field as they prepare their fields prior to telling. The organic material will mix in with their soil at different depths. After planting farmers can lay another layer of finely chopped material on top of the freshly planted field.
Mulching for Increased Organic Material, and Reduced Erosion and Evaporation.
The addition of mulch to the top of the soil can reduce the soil temperature, keep weeds down, improve drainage, attract earthworms, reduce both wind and water erosion, and can be an excellent method of adding organic material to the soil as the mulch decomposes during the course of the growing season. It is excellent for water conservation—it reduces moisture evaporation: it can help protect garden plants by retaining soil moisture when water is scarce.
Adding mulch to your field is very simple. Use the same materials that you used for making compost: leaves, dry grass, rice stalks, straw, and other agricultural residues. Simply place a thin layer on the soil after planting seeds. As the plants begin to grow add another layer until you have 5 to 10 cm.
Mulching will conserve restored soil by reducing moisture loss through evaporation, will contribute organic material and nutrients to the soil, and will prevent the loss of valuable topsoil by protecting the soil from wind and water erosion.
A consciousness raising workshop for the communities demonstrating how mulching can reduce evaporation.
1. Till and lightly moistened a small area of soil exposed to direct sunlight.
2. Mark off four small plots no more than half a meter square each.
3. Cover the first plot with a pane of glass raised about 10 cm above the soil surface.
4. Carefully and completely cover the second plot with chopped vegetation (straw, leaves, grass).
5. Loosely cover the third plot with chopped vegetation.
6. Leave the fourth plot uncovered.
Return to the test plots after one hour. Moisture should have begun to collect on the underside of the glass pane. Have the participants discuss where the moisture came from. This would be a good place to talk about soil evaporation and its effect on soils—and plants. Remove the glass and have the participants feel the soil beneath—it should still be moist.
Then have participants remove the mulch from test plots two and three. The soil should still be moist and plot two but less moist in plot three. Plot four, which was left uncovered should be even less moist and perhaps completely dry.
Compost is the earthy, dark crumbly material that results from the geek opposition of plant residue. It is rich in nutrients and organic matter and can be used as a plant fertilizer. To make compost you need the right mix of organisms, air, water and plant wastes such as grass clippings, food scraps, manures, leaf litter and straw.
Compost can be made in a bin or simply as a pile approximately a meter square and meter high. Find a location for the compost pile that is well-drained and sunny. Unless you’re lucky enough to have the materials that you need to make an instant compost pile, begin adding materials as you collect them to the top of the pile. It’s good to alternate layers of dry things like leaves and straw with layers of green grass clippings and kitchen waste. A compost pile should be turned every week or two to allow more air into the compost pile. Show the participants examples of matured compost so they know what it should look like.
Compost can be added to the field’s surface before preparation for planting—in this way it will mix in with the field’s soil during killing and be accessible to the plant’s roots. It can also be added to the surface of the field after planting and before the application of mulch. Its nutrients can then percolate into the soil with rainwater.
Even highly depleted soils can over the course of a year or several years be restored to a vital condition. The addition of organic material and compost will increase the soil’s ability to retain moisture, increase nutrients stored in the soil, increase beneficial microbes and soil flora and fauna and will improve the structure of heavily compacted soil.
Copyright © 2012, Tim Magee