Organic Fertilizer and Cover Crops Prove their Value in Kenya

The war in Ukraine has led to a rapid rise in fertilizer prices.  This has raised the price of food as exports of wheat, corn and other commodities from Ukraine constrained.   All of this threatens welfare and social stability in countries around the world.

Sustainable agriculture that relies on diverse crops and organic fertilizer and pesticides is an important buffer for family farmers in low-income countries.

International development organization World Neighbors runs agriculture programs in Kenya’s Busia and Simumu Counties.   These programs involve 22 villages and about 1800 households. World Neighbors has introduced horticultural crops such as tomatoes, watermelons, cowpeas, onions, green pepper, butternuts, eggplants and amaranth.

These crops, alternatives to corn and wheat, use far less water.   They can also be grown with minimal or no chemical fertilizers, pesticides or herbicides.

One sustainable technique is the use of cover crops, often called “green manure.”

When plants, grasses and legumes that conserve water and protect the soil are ploughed back into the soil to fertilize it, they are referred to as green manure. Common cover crops in Africa include glyricidia sepum, piliostigma reticulatum, calliandra, canavalia insiformi, and different types of legumes.

Green manure benefits include: 

*Soil erosion control. Cover crops provide protection against soil erosion as surface runoff is slowed by the cover, allowing improved moisture through increased infiltration.

*Pest and weed management.  Cover crops tend to reduce infestations by insects, diseases, nematodes and weeds.  Cover crops and their residues can also be used as mulches, suppressing the germination and growth of weed seeds and lowering soil temperatures.  

 *Pollination. Flowering cover crops support the pollination of fruit trees and, increasingly, beekeeping facilities.   These provide extra sources of income for rural farm families.

*Reduced input costs. Cover crops are a very inexpensive source of fertilizer. They absorb nitrogen from the air and fix it in the soil to be used by other crops. Periodically ploughed into fields as “green manure,” they increase carbon. This costs farmers virtually nothing. And unlike chemicals fertilizers, there is no health risk with cover crops and green manure.

*Increased soil fertility. Cover crops improve overall soil health usually within a year or two, and increasingly over time. They encourage the growth of earthworms and other insects that improve soil quality and increase nutrient availability. This increases fertility, which improves yield per unit of land.

Green manure is just one of the sustainable techniques introduced by World Neighbors to increase climate change resilience, minimize use of chemical inputs and increase output.  These techniques are proving especially important now as food and fertilizer exports are disrupted.