Impact of crop establishment and residue management on soil properties and productivity in rice-fallow ecosystems in India

The degradation of agricultural land, both chemical and biological, is a big concern all over the world. Crop cultivation practices that are distinctive to each location have negative consequences for agricultural production. Therefore, there is an urgent need for better crop and soil management techniques. This experiment was conducted for 5 years (2016-2020) to identify the best crop establishment-cum-residue management (CERM) practices and suitable crops for succession after the rice harvest in rice-fallow ecosystems of India. Experimentation was conducted in the split-plot design and each treatment was replicated thrice, having CERM in main-plot and post-rainy season/winter crops in sub-plot. All the CERM treatments had two variants, with crop residue (R+) and without crop residue (R-). Rice yields were markedly higher (19.1%-32.2%) in transplanted puddled rice with residue (TPR-R+) over conventional-till direct seeded rice (CTDSR) and zero-till DSR (ZTDSR) treatments. However, TPR adversely impacted the performance of all the post-rainy pulses/oilseed crops. Post-rainy season crop yields under ZTDSR/CTDSR were 14.9%-45.8% higher leading to higher system productivity as compared to TPR. ZTDSR with residue retention showed higher soil aggregation. The practice of ZTDSR increased the soil dehydrogenase activity (46.2%), urease activity (29.8%), soil microbial biomass carbon (65.4), and fluorescein diacetate activity (9.0%) in the crop root zone with 3.3- and 4.47-times higher earthworm population and earthworm biomass, respectively. The rice-pulse system showed 1.74-times more earthworm population over rice-oilseed sequences. Total soil organic carbon (SOC) stock in ZTDSR was 21.8% higher over TPR in 0-45 cm soil profile. Thus, the adoption of ZTDSR practices and diversification of rice-fallows with pulses crops is recommended for enhancing the crop productivity, increasing SOC stock, and improving soil biological properties in the rice-fallow ecosystems of India.