Farmers' knowledge helps develop practically applicable site-specific fertilizer rate recommendations for improving yield and grain quality of malt barley

Many participatory research works in Ethiopia and elsewhere proved that peasant farmers can classify soils according to their fertility/productivity status but these studies did not use this knowledge for developing practically applicable site-specific fertilizer rate recommendations. Experiment comprising factorial combinations of four levels of nitrogen (N) (0, 60, 120, and 180 kg ha(-1)) and two contrasting malt barley varieties (V-1= Miscal-21 versus V-2= Holker) was conducted on 10 sites representing soils of less fertility/less productivity (S-1) and fertile/productive (S-2) according to farmers' classification in 2010-2012. The objectives were to confirm and use farmers' knowledge for developing practically applicable site specific N fertilizer rate recommendations; and generate information for developing malt barley varieties with lower grain protein accumulation and higher productivity in higher N application rates. The results revealed that farmers knowledge could be used to develop practically applicable site-specific fertilizer rate recommendations. Therefore, applications of 110.5, 45.0, 137.5 and 110.5 kg N ha(-1)in S1V1, S2V1, S(1)V(2)and S2V2, respectively, are suggested for production of malt barley having 11.85% dry grain protein content with the relative higher productivity in the highlands of Ethiopia. Results also revealed that there is opportunity to develop malt barley varieties with lower grain N accumulation and higher productivity in higher N rates.