Ethiopia: Crop rotation, intercropping, and mulching help farmers improve soil fertility and productivity
Suzan Mathias can barely remember the last time her family of seven went hungry. But unpredictable rains and the high cost of farming have significantly affected her crop yields of late.
The 36-year-old mother lives in Mchemwa village, near Dodoma, the capital of Tanzania. She owns more than 40 hectares of arable land and grows many crops, including maize, millet, sorghum, and vegetables.
Agriculture is the backbone of the region’s economy, although worsening droughts are affecting farming. The changing climate and infertile soil have strongly affected production in the area.
Mrs. Mathias’ millet yields, for instance, have fallen to less than two sacks per hectare, down from five in the early 2000s. She says, “The greatest roadblock was ignorance,” referring to her lack of knowledge about practices to protect the fertility of her soil. She says, “Most of my fields were dry, failing to hold moisture for long after it rains.”
Mrs. Mathias participated in a training conducted by the Diocese of Central Tanganyika. Through the training, she learned about conservation agriculture, which is a farming practice that protects soil by minimizing plowing and other practices that disrupt the soil. Conservation agriculture protects the soil from erosion and degradation, improves soil quality, and contributes to the preservation of natural resources, while often raising yields. Since the training, Mrs. Mathias prepares her field with a tape measure, rope, machete, and ashes—rather than a tractor and plow.
She divides her land into fields which measure 20 metres square. In this way, she can more easily rotate her crops between fields. Then Mrs. Mathias harrows the soil surface slightly, leaving dead weed and crop residues on the soil surface. She uses the residues to cover the soil, which protects it from wind and rain erosion, and helps the soil retain moisture.
When planting, she digs planting basins of identical sizes, at least 15 cm deep. After the field is ready, she adds a teaspoon of ash to the planting hole, followed by a little soil and a teaspoon of organic manure. Next she adds a little soil to the hole, plants the seed, then adds a little more soil, leaving a shallow depression.
The ash helps to reduce soil acidity and protects against ants that might threaten the plant. The shallow depression retains rainwater for the growing plant.
Farmers in Dodoma district are also planting cover crops, another conservation farming practice. They intercrop sorghum or millet with cover crops that suppress weeds and add organic matter to the soil. Legumes are particularly useful cover crops. Farmers like Mrs. Mathias plant legumes such as cowpeas, pigeon peas, lablab, green gram, and jack bean as cover crops.
Samwel Elinuru is an extension officer in Dodoma district. He promotes conservation agriculture in six villages. He says that the number of farmers who practice conservation agriculture in the area has increased from 62 in 2015 to 850 this season.
He adds, “Farmers are happy [because], when using cover crops, they also get additional crops for food and for selling.”
Lawrence Lwanje is a monitoring and evaluation officer with the Diocese of Central Tanganyika, which trains farmers on conservation farming. He says, “Farmers have shown interest in adopting conservation farming. We receive endless calls from areas where we have not reached…. They want such education to convert their farming practices.”
Donald Mangwela farms in nearby Chihanga village. He says that one good reason to practice conservation farming is because it is less expensive. Mr. Mangwela explains: “In conventional farming, we use a tractor, power tiller, or plow. It’s more expensive than conservation farming, where we use only plant residues to prevent weeds. Even with a small piece of land, you are assured of more yields.”
However, he says, “For beginners, [conservation agriculture practices] need early preparation to avoid a last minute rush.” This is because beginners need more time to remove weeds and learn the new planting practices. But Mr. Elinuru says it’s worth the effort, as conservation agriculture can be less costly than conventional farming.
If you take a quick look at the farms, you can notice a difference. The crops planted with reduced tillage have grown taller and healthier than those planted with conventional methods.
Photo: Donald Mangwela in his field
This work was created with the support of Canadian Foodgrains Bank as part of the project, “Conservation Agriculture for building resilience, a climate smart agriculture approach.” This work is funded by the Government of Canada, through Global Affairs Canada, www.international.gc.ca