Effect of Conservation Agricultural and Nitrogen Management Practices on Productivity, Profitability, Nutrient-uptake and Response Functions of N-fertilization in Wheat

A field experiment was carried out at ICAR-Indian Agricultural Research Institute, New Delhi for two consecutive years to evaluate the effect of conservation agricultural and nitrogen management practices on productivity, profitability, nutrient-uptake and response functions of N-fertilization in wheat in maize-wheat cropping system. There were six main-plot treatments of tillage and crop establishment techniques, i.e. conventional tillage-flat-bed (CT-F), CT-raised-bed (CT-B), zero tillage-flat-bed with crop-residue (ZT-F+R) and without crop-residue (ZT-F), ZT-raised-bed with crop residue (ZT-B+R) and without crop-residue (ZT-B), and four sub-plot treatments of nitrogen (N; 0, 60, 120 and 180 kg N/ha). Results showed that leaf area index, relative growth rate, spike length, grains/spike, 1000-grains weight, biological yield, nutrient uptake and gross returns were recorded relatively high under ZT practices along with or without crop-residues over the CT practices, though difference among the treatments were non- significant. The biological yield, nutrient uptake (NPK) and gross returns were improved with CA practices (ZT-F+R/ZT-B+R) by 5.3-8.1, 4.8-10.1 and 7.3-10.9 %, respectively over the CT practices. The B:C ratio was recorded the maximum under ZT practices (ZT-F/ZT-B) which was significantly higher by 18.3-24.0 % over the CT practices. Significantly higher values of most of the growth, yields, nutrient uptake and economic parameters were recorded at 120 kg N/ha. Nevertheless, ZT-F+R/ZT-B+R resulted the maximum response of wheat to N-fertilization (169-172 kg/ha) and also produced the maximum grain yield (4.81-4.86 t/ha) which signifying the importance of crop-residues and ZT technology in realizing the highest yield of wheat. Therefore, the study recommends that CA (ZT-F+R/ZT-B+R) systems along with additional 50 kg N/ha in addition to the presently recommended dose of N (120 kg/ha) should be promoted among the farmers of the Indo Gangetic Plains for improving productivity, profitability and long-term sustainability of the wheat in maize-wheat cropping system.