A farewell to hunger? Nitrogen-fixing plants boost healthier crops in Ethiopia

24.10.2018
Farmers in Ethiopia have experimented with nitrogen-fixing leguminous plants in order to increase their crop yields. The grain yield results were comparable or even better than the plants receiving synthetic nitrogen fertilizer.

Soil erosion is a major problem for agricultural cultivation in Ethiopia. Many years of intensive cultivation have depleted the soil of the nutrients that are required to produce a plentiful and productive crop. In order to increase soil fertility and improve crop yield, Ethiopian farmers in Hawassa in southern Ethiopia collaborated with the University of Helsinki and Hawassa University in an experiment introducing new cultivation methods that employ nitrogen-fixing bacteria. The research project was carried out over a period of four years (2013 – 2017), and the results are promising.

“When leguminous plants were inoculated with nitrogen-fixing bacteria, it resulted in increased soil fertility and crop yield for the project participants. The bacteria enrich the soil due to their capacity to absorb nitrogen from the atmosphere. As a result, synthetic nitrogen fertilizer is no longer necessary. Besides, small-scale farmers can seldom afford synthetic fertilizer,” says Professor Kristina Lindström at the University of Helsinki.

The nitrogen-fixing bacteria, which are called rhizobia, live in symbiosis with leguminous plants in the plants’ root systems. The bacteria can form a symbiosis with protein-rich plants such as soybean, pea, faba bean, peanut, clover and lupine. The best result is achieved by inoculating the seed with cultivated rhizobia.

 “The challenge for Ethiopia is that very few facilities or laboratories are able to mass produce the rhizobia as biofertilizer for farmers,” says Aregu Aserse, post doc researcher at the University of Helsinki.

“The bacterial strain must be adapted to Ethiopian soil and temperature conditions. You cannot use a strain of bacteria that has been produced in Finland, for example,” Lindström explains. 

In addition, different plants require different rhizobia. In their work in Hawassa, Lindström and Aserse have focused on studying what types of bacteria are suitable for symbiosis with soybean (Glycine max) and common bean (Phaseolus vulgaris).

Two new species of bacteria discovered in Ethiopia

During the course of their work, Aserse and Lindström discovered two new species of rhizobia in Ethiopia: Rhizobium ethiopicum, which lives in symbiosis with the common bean, and Bradyrhizobium shewense, whose host Erythrina brucei is a tree species endemic to Ethiopia.

“Ethiopia’s biological diversity is immense, and there is also an amazing diversity in terms of soil bacteria. The chances of discovering bacteria that are suitable for varying conditions are therefore very good,” Lindström says.

In 2015, Ethiopia was hit hard by drought and famine due to an exceptionally strong El Niño. The researchers hope that their knowledge and methods can be used to avert future famines.

“The greatest success of the project in Hawassa was that the production and grain yield of common bean and soybean were improved as a result of rhizobia inoculation. We discovered that the drought tolerance of the plants was improved during the drought season in 2015 because of the rhizobia inoculation,” says Aserse.

The researchers hope that more and more Ethiopian farmers will be able to benefit from their method in the future.

“Everyone who has been involved in this project, farmers and researchers alike, has seen the benefits. In the first year only four farmers were willing to try the inoculation method using soybean. The following year, nearly everyone in the village had heard about the results and wanted to participate,” says Mila Sell, senior specialist at the Finnish Natural Resources Institute 

The project participants recommend establishing a local soybean cooperative so that the method can be adopted on a larger scale.

“A member-controlled cooperative could enable the farmers to reach a larger market, and this might provide them with the incentive to cultivate soybean instead of khat (Catha edulis), a narcotic plant that is exported in large amounts and is an important source of income. This would have a positive impact on local food supply and on the quality of arable soil, since leguminous plants enrich the soil, whereas khat depletes it,” says Professor Kristina Lindström.

About  the SOILMAN research project:

The aim of the SOILMAN project was to make use of ecosystem services to improve food security, crop productivity and soil health in Ethiopia.

A novel, transdisciplinary approach to implement biofertilizer use by integration of inoculant practices into the local farming system was taken near Hawassa, 270 km south of Addis Abeba.

An innovation platform (IP) was established with farmers from two villages, both male and female members of the households. Local stakeholders, including extension agents, experts from Hawassa University, and representatives of a farmers’ cooperative, where invited to participate in the IP activity.

The platform included farm visits, plot experiments, trainings and monthly meetings facilitated by a local expert from the university who spoke the local language. IP member farmers were offered seeds and biofertilizer for the traditional common bean and the novel crop soybean, and in the meetings they could share their experiences and knowledge.

During annual workshops, based on the needs and wishes of IP members, experts on rhizobia, soil science, nutrition, agronomy and cooperatives shared their knowledge based on questions raised by the platform participants. During the cooking workshop participants baked bread and cooked dishes with soybean, guided by the nutritionist.

An innovation platform is defined as ‘a space for learning and change‘.

Innovation platform. The SOILMAN project use an Innovation platform (IP) as a tool to bring together stakeholders and collect and implement ideas. Picture: Alfred Ombati / ILRI.

The transdisciplinary, participatory approach proved to be an excellent tool for capacity building and empowering IP members, especially women farmers. In the IP, farmers, scientists and other stakeholders share and exchange knowledge and together develop sustainable practices.

SOILMAN was funded by the Academy of Finland and carried out by the University of Helsinki 2013-2017.

Homepage: https://blogs.helsinki.fi/soilman-­uh/

Publication: Sell, Mila & Vihinen, Hilkka & Gabiso, Galfato & Lindström, Kristina. (2018). Innovation platforms: a tool to enhance small-scale farmer potential through co-creation. Development in Practice. 1-13. 10.1080/09614524.2018.1510473.