Long-Term Conservation Agriculture and Intensified Cropping Systems: Effects on Growth, Yield, Water, and Energy-use Efficiency of Maize in Northwestern India

Conservation agriculture（CA）-based best-bet crop management practices may increase crop and water productivity, while conserving and sustaining natural resources. We evaluated the performance of rainy season maize during 2014 under an ongoing long-term trial（established in 2008） with three tillage practices, i.e., permanent bed（PB）, zero tillage（ZT）, and conventional tillage（CT） as main plots, and four intensified maize-based cropping systems, i.e., maize-wheat-mungbean, maize-chickpea-Sesbania（MCS）, maizemustard-mungbean, and maize-maize-Sesbania) as subplot treatments. In the seventh rainy season of the experiment, maize growth parameters, yield attributes, yield, and water-and energy-use efficiency were highest at fixed plots under ZT. Maize growth parameters were significantly（P < 0.05） superior under ZT and PB compared with CT. Maize yield attributes, including cobs per m2（7.8）, cob length（0.183 m）, grain rows per cob（13.8）, and grains per row（35.6）, were significantly higher under ZT than CT; however, no significant effect of cropping systems was found on maize growth and yield attributes. Zero tillage exhibited the highest maize productivity(4 589 kg ha-1). However, among the cropping systems, MCS exhibited the highest maize productivity(4 582 kg ha-1). In maize, water use was reduced by 80.2–120.9 mm ha-1under ZT and PB compared with CT, which ultimately enhanced the economic water-use efficiency by 42.0% and 36.6%, respectively. The ZT and PB showed a 3.5%–31.8% increase in soil organic carbon（SOC） at different soil depths（0–0.45 m）, and a 32.3%–39.9% increase in energy productivity compared with CT. Overall, our results showed that CA-based ZT and PB practices coupled with diversified maize-based cropping systems effectively enhanced maize yield and SOC,as well as water-and energy-use efficiency, in northwestern India.