Productivity and nutrient uptake of soybean (GZycine max) as influenced by bio-inoculants and farmyard manure under rainfed conditions

A field experiment was conducted at Wadura in Jammu & Kashmir during the rainy (kharif) season of 2004 and 2005 to study the efficiency of Rhizobium, Azotobacter, phosphate-solubilizing bacteria (PSB) and farmyard ma- nure (FYM) on performance of rainfed soybean [Glycine max (L.) Merr.] and soil fertility. Results revealed that sole or dual inoculation of soybean with biofertilizers, application of FYM and recommended dose of fertilizer (RDF) sig- nificantly increased the plant growth, nodulation, seed and straw yields as well as N and K uptake over the control. Application of Rhizobium + Azotobacteri PSB + FYM showed significantly higher number and weight of nodules, but it was on par with that of Rhizobium + PSB + FYM and RDF. The improvement in seed yield over the control was 46.6, 42.2 and 38.8% under RDF, Rhizobium + Azotobacter + PSB + FYM and Rhizobium + PSB + FYM re- spectively. Further, inoculation of soybean with ~hizobium and PSB registered respectively 19.8 and 11.2% in- crease in grain yield over uninoculated control. Maximum N and P uptake, and available P were recorded with RDF, followed by Rhizobium + Azotobacter +PSB +FYM and Rhizobium + PSB + FYM, whereas the highest K up- take, organic C, and the available N and K were observed with Rhizobium + Azotobacter + PSB + FYM. Applica- tion of Rhizobium + Azotobacter+ PSB + FYM increased the available soil N by 31.2 kglha and available P by 2.05 kglha over the initial level.