Identification of a resource-efficient integrated crop management practice for the rice-wheat rotations in south Asian Indo-Gangetic Plains

Abstract

Conservation agriculture (CA) coupled with the integrated crop management (ICM)-practices based on a whole-farm approach could preserve the agroecosystems to achieve the soil-related Sustainable Development Goals (SDGs). Hence, eight conventional and CA-based ICM practices have been evaluated for 6 years in a direct seeded rice-zero till wheat rotation; wherein, ICM1&2- conventional (CT) rice followed by (fb) flatbed wheat, ICM3&4- CT direct seeded rice (DSR) fb raised-bed wheat, ICM5&6- CA-based zero tilled (ZT) DSR fb ZT wheat with the wheat and rice residues, and ICM7&8- CA-based ZTDSR fb ZT wheat with the wheat, mungbean, and rice residues. The CA-based ICM7–8 practices outperformed the traditional (CT)-based ICM1–4 practices in terms of wheat equivalent yields (WEY) (10.8–14.7%) and sustainable yield indices (SYI) of rice (10.8–21.7%) and wheat (12.9–16.1%) crops, demonstrating the greater sustainability of RWR. Additionally, the ICM techniques led to a substantial (p < 0.05) improvement in the properties governing soil quality throughout 0.0–0.45 m soil depth. The ICM7–8 practices improved the soil quality index (SQI) by 24.7% and 56.2% compared to the ICM5–6 and ICM1–4 practices, respectively. The results showed that the SQI indicators including total carbon (TC), alkaline phosphatase (APA), urease (UA), nitrogen (N), and water-stable aggregates (WSA, 0.2 mm) were all improved. CA-based ICM5–8 practices substantially reduced the carbon footprints in terms of kg CO2-eq. ha−1 ranging from 9.1% to 47% compared to the CT-based ICM1–4 practices. In contrast, carbon efficiency (7.38% ± 0.06), and carbon sustainability index (CSI) (6.38 ± 0.06) were superior in the CT-derived ICM2&4 practices. Thus, the CA-based ICM practices proved to be environmentally more safe and clean and can thus sustain the food and soil security of the extensive rice-wheat rotation under the South Asian ecologies.