Vol. 12, Issue 4 (2023)

Author(s):
PK Singh, RK Naresh, Rajan Bhatt, Himanshu Tiwari, Aashu Rajput, Lavudya Sampath, Smruti Ranjan Padhan and Goyal Akash M

Abstract:
Rice–wheat cropping system in north-western Indo-Gangetic Plains performed a crucial role in the national food security. However, the widespread and intensive cultivation of this system has led to serious problems such as declining groundwater table with sharp increase in number of districts under over-exploitation category, higher greenhouse gases emission and herbicide resistance in weeds, causing stagnant crop productivity and lesser profitability. In this review article, an attempt has been made to discuss the major issues pertaining to intensive rice–wheat cultivation amidst climate vagaries and futuristic approach to address these challenges. Intensive tillage operations, indiscriminate use of irrigation water, chemical fertilizers, and pesticides and crop biomass burning have made the conventional rice–wheat (RW) system highly energy-intensive and inefficient. In the recent past, portfolios of climate-smart agricultural practices (CSAP) have been promoted as a potential alternative to improve the energy efficiency in conventional RW system. Therefore, to evaluate the energy input–output relation, energy flow and economic efficiency in various combinations of crop management options, a review study was conducted. The net energy, energy use efficiency and energy productivity were 11–18, 31–51 and 29–53% higher under CSAP in RW system than conventional tillage without residue, respectively. However, renewable and non-renewable energy inputs were 14 and 33% higher in conventional tillage without residue compared to CSAP, respectively, it showed that conventional tillage without residue practices mostly dependents on non-renewable energy sources whereas CSAP dependents on renewable energy sources. Similarly, the adoption of CSAP improved the biomass yield, net farm income and economic efficiency by 6–9, 18–23 and 42–58%, respectively compared to conventional tillage without residue. Greenhouse gas emissions were also ~63% higher in conventional practices compared to CSAP. The energy input of under traditional method was 85.4 GJ/ha, and the energy output was 59.7 GJ/ha. Among all energy input elements, mineral fertilizers accounted for the highest proportion of energy input, accounting for 48.31%. Under water-saving irrigation, the energy input and output are 72.3 GJ/ha and 62.3 GJ/ha; the highest energy input is also mineral fertilizer. The total input energy for rice-wheat cultivation as 63825 and 50799 MJha^-1 respectively. Main contributors are electricity, fertilizer and diesel for both crops; however irrigation water is also a significant contributor in rice. The yield per unit energy use is relatively low and warrants better crop management practices to reduce the environmental footprint of the rice-wheat cropping system. Overall, the adoption of CSAP could be a viable alternative for improving energy use efficiency, farm profitability and eco-efficiency in the RW system.