Effect of tank silt application and integrated nutrient management on growth, yield and soil enzymatic activity in rainfed maize based cropping system

A field experiment was conducted during kharif and rabi seasons of 2010-2015 with maize-horsegram sequence to study the combined effect of application of tank silt, conjunctive use of chemical fertilizers and organic manure, and biofertilizers on growth and yield of maize and horsegram and soil enzymatic activity. The experiment was laid with 12 treatments with various combinations of organic - chemical nutrient management, with and without biofertilizers. Significantly higher leaf area index was observed with application of 75% recommended dose of fertilizer (RDF) + tank silt with and without biofertilizers, while significantly higher plant height was observed in 75% RDF + FYM @ 5 t/ha without biofertilizer application, followed by 75% RDF + FYM @ 5t/ha with biofertilizer application. Higher total chlorophyll (5.98 mg/g) was observed in 100% RDF, while higher carotenoids (4.41 mg/g) were observed with 75% RDF + FYM + biofertilizers. This study indicated that 25% of RDF can be substituted with locally available FYM or tank silt for higher yields. The activities of soil enzymes viz., dehydrogenase, aryl sulfatase and urease were also influenced by application of tank silt or FYM along with biofertilizers. Besides, short duration rabi horsegram was grown in the field on residual fertility in the post rainy season which increased the overall system yield by up to 5.4 t/ha, which otherwise will be kept fallow.