Influence of Organic Manures on Growth and Yield of Soyabean and on Soil Quality.

Abstract: A field experiment was conducted during kharif seasons of 2013, 2014, 2015 and 2016 on red sandy loam soil to evaluate the impact of organic production practices on growth and yield of soybean under Cauvery Command Area of Karnataka. The experiment was laid out in RCBD design with three replication. There were totally 11treatment combinations comprising different levels of compost (equivalent to 75%N, 100%N and 125%N) with recommended FYM, beejambrutha and jeevamrutha. The results indicated that, application of 100% N equivalent compost + recommended FYM (10t/ha) + beejamrutha(seed treatment) + jeevamrutha (500 liter/ha) recorded significantly higher grain yield during all the years of experimentation(1174, 1173, 1258 and 1325 kg/ha, respectively) and in their pooled data (1233 kg/ha) followed by application of 100 % N equivalent compost + beejamrutha + jeevamrutha and 125 % N equivalent compost + beejamrutha + jeevamrutha. The pH reduced significantly and became closure to neutral (6.76) as compared to initial value (7.34). The bulk density was also reduced due to application of organics as compared to initial values. The organic carbon content of the soil (0.46%) increased to the extent of 35% as compared to initial values (0.34%). This enhanced organic carbon content improved the CEC of the soil and soil available nitrogen, phosphorous and potassium content. The soil available N increased from 229 kg/ha to 289 kg/ha, soil available P2O5 from 19 kg/ha to 36 kg/ha and soil available K2O from 135 kg/ha to 186 kg/ha. This increased availability of major nutrients was the main reason for increased seed yield in organic treatments. All the organic treatments also recorded significantly higher seed protein content in soybean as compared to RDF. Among the organic treatments, application of 100% N equivalent compost + recommended FYM + beejamrutha + jeevamrutha found feasible and economically viable with higher net returns (Rs. 8570) and B:C ratio (1.49) as compared to other treatments.