The Use of Biofertilizer by Smallholder Farmers and its Impact on Productivity of Pulse- Cereal Cropping System in Arsi Zone, Oromia Regional State, Southeastern Ethiopia

Abstract

Commercial production and distribution of biofertilizer for increasing yields of pulse crops in Ethiopia started as recently as two decades ago after the agricultural research system began working on biofertilizer. Consequently, farmers have been inoculating seeds of pulse crops with rhizobium bacteria to get higher yields using rhizobium strains disseminated by the research system. Similarly, smallholder farmers in Lemu Bilbilo and Digelu Tijo districts (woredas) of Arsi Zone of the Oromia Regional State in southeastern Ethiopia have been inoculating faba bean and field pea seeds with rhizobium bacteria for increasing yields of the crops since 2010. However, there is no empirical evidence for agronomic and agroecological benefits that the farmers obtain from using the technology. Therefore, a methodical assessment was done to investigate the effects of biofertilizer (seed inoculation with rhizobium) on the productivity of faba bean and subsequently grown wheat and barley  crops and the benefits that farmers obtain in terms of yield and sustainability of the farming system. Both qualitative and quantitative data were collected from four kebeles in the two
woredas through focus group discussions (FGD) and key informant interviews (KII) involving 150 farmers, agricultural experts, development agents, researchers, and community leaders. The results revealed that smallholder farmers who planted rhizobium-inoculated faba bean seed gained additional yield benefits of 79%, 66%, and 42% for faba bean, wheat, and barley, respectively, over farmers who planted uninoculated seeds. In addition, farmers reported that they derived a range of other benefits which included improved soil fertility, need for lower amounts of nitrogen fertilizers to produce cereals, low faba bean disease incidence, more biomass production for returning to land as a crop residue, and larger-sized
faba bean seeds that take shorter time to cook. The farmers also reported an opportunity to grow faba bean profitably on less fertile land. It is concluded that planting rhizobiuminoculated faba bean seed significantly increased the yields of all three crops grown in the rotation system, with significant implications for enhanced agroecological benefits and sustainable pulse-cereal production system.