Long‐term conservation agriculture improves soil carbon, energy efficiency, weed suppression, and productivity in the rice–wheat cropping system

Abstract

Abstract Sustainable intensification of the rice–wheat cropping system (RWCS) is essential to address increasing weed pressure, soil carbon loss, rising energy demand and declining farm profitability under long‐term conventional management on the Indo‐Gangetic Plain. Therefore, this study assessed the ninth year (2023–2024) impact of different crop establishment methods in a long‐term field experiment initiated in 2015 in eastern Uttar Pradesh, India. The results demonstrated that, compared with conventional practice (CE 1 ), full conservation agriculture (CA) (CE 6 ) significantly reduced weed density and biomass in both rice and wheat, with stronger suppression at later growth stages. These gains contributed to 34.6% higher rice yield (4.78 t ha −1 ) and 17.9% higher wheat yield (4.81 t ha −1 ). Also, CA improved soil physical and chemical properties by lowering bulk density and increasing soil organic carbon, available nitrogen, phosphorus, and potassium by approximately 34, 34.5, 51.7, and 7%, respectively. Carbon stock increased to 23.36 Mg C ha −1 , corresponding to 85.74 Mg CO 2 e ha −1 and a net sequestration of 18.40 Mg CO 2 e ha. Further, energy analysis showed that CE6 reduced input energy by 27.3% while increasing output energy, leading to 49% higher net energy and improved energy‐use efficiency, leading to lower production costs and higher net returns and benefit–cost ratios. Partial CA systems also delivered measurable agronomic and economic benefits, indicating feasible transition pathways for farmers. Overall, the study demonstrates that long‐term CA strengthens weed suppression, soil carbon sequestration, energy efficiency, and crop productivity, supporting climate‐resilient and sustainable cropping systems.