干旱区生态环境知识资源中心

Soil nutrient contents were determined in 802 surface soil samples (0-15 cm deep) collected from farmers’ fields that support extensive cultivation of soybean (Glycine max L.) and finger millet (Eleusine coracana G.), spread across three districts, in the semi-arid regions of Karnataka, India. Following soil analysis, on-farm crop trials were conducted during 2005-2007 to study the crop response to the soil application of nitrogen (N), phosphorus (P), sulfur (S), boron (B), and zinc (Zn) fertilizers. Analyses of soil samples revealed that 4-83% fields were deficient in N, 34-65% in P, 83-93% in extractable S, 53-96% in B, and 34-88% of farmers’ fields were deficient in Zn. On-farm trials conducted during the three rainy seasons (2005, 2006, and 2007) significantly (P <= 0.05) enhanced crop productivity indices such as yields of grain, stover, and total biomass in soybean and finger millet crops. Integrated management of deficient nutrients in finger millet and soybean crops significantly enhanced the grain and straw uptake of N, P, K, S, and Zn.