Influence of integrated nutrient management on the productivity, quality and soil health of maize (Zea mays)-wheat (Triticum aestivum) cropping system

A field experiment was conducted at New Delhi during the kharif and rabi season of 2006-07 and 2007-08 with maize (Zea mays L.)-wheat [Triticum aestivum (L.) emend. Fiori & Paol] cropping sequence to evaluate influence of four organic sources viz., control, Sesbania green manure, wheat straw and their combination and three levels of fertilizer N viz. 0, 60 and 120 kg /ha in maize and four levels of N viz. 0, 40, 80 and 120 kg/ha in succeeding wheat. Direct and residual effect of organic sources significantly affected the system productivity, quality, nutrient uptake, and soil quality of maize-wheat cropping sequence. Sesbania green manure in combination with wheat straw followed by Sesbania green manure alone recorded significant improvement in system productivity (12.5 tonne/ha), protein content of maize (8.51%) and wheat (10.24%) and N, P and K uptake of both the crops and the system. Addition of Sesbania green manure along with wheat straw improved the available N, P, K and organic carbon in soil to the tune of 25.3, 49.3, 5.9.and 11.9 % over control, respectively. A significant response of fertilizer N up to 120 kg/ha was recorded on the system productivity, quality and nutrient uptake of maize and the residual effect of that also influenced significantly the NPK uptake by wheat and system as a whole. Wheat also responded significantly to direct application of fertilizer N for N and protein content in grain up to 80 kg/ ha and up to 120 kg/ ha in terms of nutrient uptake. It was concluded that integrated use of organic and inorganic sources of N is es- sential to achieve high productivity and quality of maize-wheat cropping system and to maintain soil fertility.