Soil bacteria help Ethiopian farmers grow more nutritious and higher yielding crops

from International Development Research Centre
Published on 25 Jan 2013 View Original

Researchers from Canada and Ethiopia are testing, adapting, and promoting practical solutions to grow pulse crops in poor regions of Ethiopia. Pulses — such as chickpeas, lentils, and beans — can fight malnutrition and release the soil’s potential for growing high-yield, healthy pulses.

The opportunity: Locally enhanced pulse seeds

A Canadian International Food Security Research Fund (CIFSRF) project led by scientists at the University of Saskatchewan in Canada and Hawassa University in Ethiopia has found a way to feed the depleted soil and add protein to people’s diets. Their efforts are critical to Ethiopia, which has one of the highest rates of malnutrition in the world. The problem is particularly acute in Southern Ethiopia, where livelihoods and diets are heavily dependent on high-yield cereals like wheat and teff and root vegetables like cassava. These crops deplete the soil of nitrogen, are high in carbohydrates, and contain minimal protein.

The researchers have identified local and abundant nitrogen-fixing bacteria that, when spread onto the seeds of improved pulse varieties, can increase crop yields up to 60% and leave valuable nutrients in the soil for the next season's crop.

These microorganisms — called rhizobia — are creating new incentives for Ethiopian farmers to supplement staple crops with high-protein pulses. The peas, lentils, and beans can be eaten (or sold for additional income), thus reducing widespread malnutrition, particularly among children and women in rural areas. They also provide an accessible, effective, and affordable alternative to inorganic fertilizers, which few smallholder farmers can afford.

“Good soil fertility is critical to increasing crop yields, which can make a real difference for food security and the incomes of smallholders, especially women and their children,” says Sheleme Beyene Jiru, a soil scientist at Hawassa University.

Finding the right seeds and bacteria

Until this project, researchers had no idea such diversity of rhizobia existed in Ethiopia. Rhizobia are able to extract atmospheric nitrogen found in the soil and convert it into a usable form for plants. These microorganisms provide ample nitrogen for growing protein-rich pulse crops, and may leave some left over for the next growing season of cereal and root crops.

“If your goal is to grow protein, you need nitrogen,” explains Fran Walley, an expert in soil fertility at the University of Saskatchewan and a member of the CIFSRF project team. “Given that nitrogen fertilizers are fairly expensive, there is tremendous potential to exploit a resource that is abundant in Ethiopian soil, and well adapted to the region’s harsh growing conditions.”

First, researchers needed to identify which strains of rhizobia — of the many indigenous strains in the country — work best with specific pulses in the four agricultural areas of this project. Of the 150 chickpea and 165 lentil rhizobia collected, laboratory studies identified 80 top strains for each crop. The study moved next to farmers’ fields where preliminary results indicate that several of these local rhizobia perform as well, if not better, than the commercially available strains imported from Canada. Further tests are underway.

Researchers are also working closely with farmers to identify and field test high-yield chickpea and lentil varieties that are drought tolerant, disease resistant, and rich in micronutrients. The trials compared the performance of these other varieties from across the country with those traditionally grown by farmers to see how each performed with or without local rhizobia. The results surprised both the researchers and the local farmers.

For example, 15 farmer field trials determined that these newly introduced chickpea varieties (treated with indigenous rhizobia) produced significantly higher yields compared to local varieties. In fact, one improved chickpea variety produced 62% higher yields than the variety farmers traditionally grow (3.4 versus 2.1 tonnes per hectare).

Higher incomes and exports

“Some of these regions grow only one major crop per year. We have shown there is potential to put chickpeas in rotation after cereal crops, which means more income for farmers,” says Bunyamin Tar'an at the University of Saskatchewan’s Crop Development Centre. “They are very interested in this at the national level because they see the opportunity to expand chickpea production to other regions.”

The results could help the country boost its national chickpea production from a low of 1.3 tonnes per hectare (even lower in Southern Ethiopia) to its potential yield of 4.5 tonnes per hectare. These higher yields would support the government’s goals of expanding export markets for pulse crops, and reducing widespread malnutrition.

In addition, the project is testing the potential of snap beans under rain-fed conditions. Preliminary observations suggest that, when coated with rhizobia, they produce beans similar in quality to those grown using irrigation and inorganic fertilizer. Snap bean is an export commodity crop that has only been recently introduced in Ethiopia, yet has a great economic potential. In 2008, the country’s snap-bean exports generated more than CA$15 million in revenue.

Next Steps: Ensuring future supplies

Researchers have identified the best-performing rhizobia strains and the best crop varieties for specific regions of Southern Ethiopia. The next goal is to ensure an adequate supply of both rhizobia and seed to meet farmers’ needs.

“Quality seed supply is one of the key challenges for scaling up this research,” Tar'an says. In the short-term, seed produced in the current trial was distributed to another 30 farms participating in more field trials beginning in September 2012. Once that trial ends, the plan is to have each of those 30 farmers supply seed to three or four more farmers for the next growing season. Over the coming year, more experienced farmers will receive training as seed growers at agricultural research centres to ensure a sustainable local supply once the project ends.

Researchers are also exploring opportunities to manufacture rhizobia locally. At one point in Canada they were made at the University of Saskatchewan. Likewise in Ethiopia, they could be made by a university and distributed to farmers through local farm cooperatives.


Lead researchers: Dr. Sheleme Beyene (Hawassa University, Ethiopia)
Dr. Bunyamin Tar’an and Dr. Fran Walley (University of Saskatchewan, Canada)
Country: Ethiopia
Funding: CA$999,935 Duration: September 2010 to March 2013

For more information on this project, contact Pascal Sanginga, Senior Program Specialist, Nairobi, Kenya ( or Kevin Tiessen, Senior Program Officer, Ottawa, Canada (