Organic crop productivity demonstration using tillage and biofertilizer management approaches at Kulumsa, Southeastern Ethiopia

Organic agriculture assures sustainability of crop production with low or no use of external agricultural inputs. It is practiced under small scale level for high value crop such as coffee in Ethiopia. Although crop rotation as part of organic agriculture is practiced in food security crops like wheat and faba bean, it is not implemented under large scale production schemes. Thus, a field research was conducted to test and demonstrate organic farming and associated tillage and fertility trials at Kulumsa, southeastern Ethiopia. Interventions were deep plowing followed by soil harmonization using alfalfa and lathyrus planting in 2016. Then, all the planted biomass were converted to the soil during the second heavy plowing before setting up the trials. Separate sets of large blocks (20 ha) of field experiments were undertaken in 2017 main cropping season. Tillage experiments using mechanized and oxen plowing treatments were compared in faba bean and tef demonstration fields in 2.28 ha per each crop. Faba bean productivity was higher in oxen than tractor plowed field. Although non-significant, application of bio fertilizer gave better faba bean yield with tractor than oxen plowed field. Tef yield was better in oxen than tractor plowed field. Similarly, five crops (0.75 ha each) were evaluated for their productivity in organic model farm experiment under green manure and with additional decomposed animal manure. Organic based bread wheat (3300 kg/ha) production showed above national average yield. Productivity of potato was 24,444 kg/ha and that of fresh alfalfa biomass was11, 640 kg/ha. Thus, agroecological system approaches such as proper tillage, soil harmonization and crop rotation showed significant effect to reduce weed species composition and increased productivity at last.