Sustaining Soil Health Using Biodigested Organic Manures and Inorganic Manure in a Rice-Based Cropping System.
Maragatham Narayanan, Tamil Nadu Agricultural Univ, TNAU, Coimbatore , Tamil Nadu, AZ, India
Integrated nutrient management involving judicious use of various sources of plant nutrients such as chemical fertilizers, organic sources and biofertilizer helps to maintain or improve soil fertility and sustain crop production. In this context, resource like organic and biodigested organic manures are tried for groundnut-rice cropping system at TNAU, Coimbatore ,India with the objective of evaluating the effect of integrated nutrient management in groundnut - rice cropping system. Well decomposed cow dung manure, poultry manure, goat manure and their respective biodigested manures were used in combination with and without recommended dose of fertilizers for the Kharif crop of groundnut. The substitutions were done to the tune of 25 and 50% on N basis. To study the residual effect in the rabi rice crop, no manuring was doneAfter the harvest of the second crop of rice the soil fertility status was analyzed.Whenever organic manures (OM) or boigiested organic manures (BOM) were used , there was an improvement in the soil available N content. Slow decomposition of OM or BOM leads to steady N release to meet the requirement of rice crop at critical stages. Even after the growing period, mineralization of N continued and added to the soil pool. This helped in maintaining the soil available N, inspite of the depletion by the rice crop and this was well pronounced with the incorporation of OM or BOM along with recommended NPK. Soil available N balance after the crop sequence indicated that 50% of N as BCMS (biodigested cattle manure slurry ) or BPMS (biodigested poultry manure slurry 0 + 50% as N as in inorganic fertilizer during first season as well as application of 100% recommended NPK to second season improved the soil available N status when compared to pre experimental level. Yield also followed the same trend.