Conservation agriculture and nitrogen management in maize–wheat cropping system: effect on growth, productivity and economics of wheat

A study was conducted at ICAR-Indian Agricultural Research Institute, New Delhi to assess the effect of six combinations 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) in combination of four levels of fertilizer-nitrogen (N; 0, 60, 120 and 180 kg N/ha) on growth, yield and economics of wheat (Triticum aestivum L. emend. Fiori & Paol) in conservation agriculture based maize (Zea mays L.)-wheat cropping system. The performance of the wheat in terms of growth, yield and net returns was observed statistically similar under different tillage and establishment techniques but it was differed significantly (p ≤ 0.05) due to different levels of N. Crop-residue applied treatments (ZT-F+R/ZT-B+R) improved the grain and straw yields over without crop-residue applied ZT (by 5.2 and 3.6% under flat-planting; and 7.7 and 4.1% under raised-bed planting systems, respectively) and CT practices (by 12.0 and 5.4% under flat-planting and 8.1 and 3.4% under raised-bed planting systems, respectively). The ZT technology reduced the cost of cultivation by 9.8% and improved the net profits by 9.0% over the CT practices. Further, recycling of crop residue under ZT practices (ZT-F+R/ZT-B+R) not only produced the maximum grain yield (8.0-12.0% higher) but also generated either equal or higher net profits over the CT practices. The growth, yield attributes, grain yield, straw yield and net returns were increased significantly up to 120 kg N/ha, though the maximum values of most of these parameters were recorded at 180 kg N/ha. Therefore, it can be concluded that ZT practices along with crop residues and 120 kg N/ha could be adopted to make the wheat cultivation more remunerative and sustainable.