Direct seeded rice in sequence with zero-tillage wheat in north-western India: addressing system-based sustainability issues

Resource conserving and eco-friendly interventions through improved crop establishment are the need of time to produce more with less resources, and mitigating climatic vulnerabilities and protecting environmental quality in the rice–wheat cropping system (RWCS) of India. In this context, seven years (2010–2017) field experimentation at Karnal, Haryana, India revealed that the weed infestation was more intensified and diversified in direct seeded rice (DSR) than puddled transplanted rice (PTR), and even eliminating puddling in rice-induced more infestation of Phalaris minor in succeeding wheat crop. Residue retention in zero-till (ZT) DSR and rotating conventional till (CT) DSR with PTR reduced weed pressure compared to continuous DSR. Root knot and plant parasitic nematodes were less in DSR than PTR but reverse was true for saprozoic nematodes in DSR and ZT situations. CTDSR, ZTDSR (with or without residues), and ZT/CT machine-transplanted rice (MTR) produced grain yields at par (P = 0.05) with PTR. The grain yield of ZT wheat (5.03–6.90 t ha−1) in sequence with CT/ZT rice establishment (DSR/MTR) was 0.3–0.6 t ha−1 higher than what it was attained after puddled rice systems. Net returns from DSR/MTR-based cropping systems were higher than PTR, with 22–31% saving of labor. Irrigation water productivity was also higher under DSR (27.5–29.9 kg ha-cm−1) than PTR (23.7 kg ha-cm−1), with 17.5–22.8% reduction in irrigation input. There was also improvement in soil health under ZTDSR/MTR (higher OC, N, P and K, and lower bulk density) compared to PTR. Overall, the resource conservation and soil health improvement through these planting methods signaled toward system stability over trade-offs in RWCS.