Sustainable Intensification of Rice Fallows with Oilseeds and Pulses: Effects on Soil Aggregation, Organic Carbon Dynamics, and Crop Productivity in Eastern Indo-Gangetic Plains

Abstract

Climate-smart agriculture (CSA) practices are becoming increasingly important due to their better adaptability to harsh climatic conditions (in general) and the unpredictability of monsoons in India (in particular). Conventional rice cultivation (e.g., PTR) involves intensive tilling followed by intensive puddling in standing water that destroys the soil aggregation and depletes carbon pools. Therefore, alternative crop establishment methods need to be devised for the sustainability of system productivity, and the suitabilities of potential oilseeds and pulses need to be tested for cropping intensification in rice-fallow regions. Hence, an ongoing experiment (implemented in 2016) was evaluated to identify the appropriate CSA management practices in restoring soil C and physical health under diversified cropping systems in the rice-fallow system of eastern India. Six tillage and crop establishment methods along with residue management were kept as the main plots [zero-till-direct-seeded rice (ZTDSR), conventional-till-DSR (CT-DSR), puddled transplanted rice (PTR), ZTDSR with rice residue retentions (ZTDSRR+), CTDSR with rice residue retention (CTDSRR+), PTR with rice residue retention (PTRR+)] while five winter/post-rainy crops (oilseeds and pulses) were raised in a subplot. In the ZTDSRR+ production system, soil macro-aggregate (%), macro-aggregate-associated C, MWD, and GMD of aggregates increased by 60.1, 71.3, 42.1, and 17.1%, respectively, in comparison to conventional tillage practices (PTR). The carbon management index (CMI) was 58% more in the ZTDSRR+ production system compared to PTR. Among the winter crops, chickpeas recorded higher values of soil structural indices and C content. In the PTR production system, system productivity, in terms of rice equivalent yield, was comparable to ZTDSRR+. ZT with residue retention in rice followed by post-rainy/winter pulses led to higher C content and structural stability of the soil. Thus, CSA management practices can improve the crop productivity as well as soil health of rice-fallow production systems of eastern India and comparable agroecotypes of South Asia.

Management of soil cover and tillage regimes in upland rice-sweet corn systems for better system performance, energy use and carbon footprints

“…Factors such as soil health, water usage, GHG emissions, and long-term sustainability should be evaluated to make more comprehensive conclusions about the benefits and trade-offs of different tillage methods. Taking those into account, MT emerges as the superior tillage approach since it maintains soil health, is cost-effective, and yields outcomes on par with those of CT practices in the short term while after stabilization ZT can potentially improve the system's performance [ 26 , 39 ]. This experiment showed that live mulching had the highest net energy and energy output.…”

Fallowing Strategy and Its Impact on Surface Water and Groundwater Withdrawal, and Agricultural Economics: A System Dynamics Approach in Southern New Mexico

“…Some research is descriptive in nature rather than constituting a thorough critical analysis of the studies under examination [18][19][20][21][22]. Other ones are quantitative, but there is no comprehensive approach in terms of combining the multiple aspects of the problem, including hydrology, social, and economic aspects [23][24][25][26][27].…”

Intensification of Rice-Fallow Agroecosystem of South Asia with Oilseeds and Pulses: Impacts on System Productivity, Soil Carbon Dynamics and Energetics

“…Rice (Oryza sativa L.), largely cultivated by transplanting in rainfed conditions during the southeast monsoon season, is a staple food crop of the eastern region of India. Puddling, i.e., tillage in standing water, is extensively practiced for rice transplanting, which minimizes percolation losses, suppresses weed growth and improves plant nutrient availability [5]. However, puddling is known to degrade the soil health by the formation of hardpan in the sub-soil, destroying soil aggregation and decreasing the population of beneficial microorganisms, thus reducing crop yields of subsequent post-rainy crops in ricefallows [6].…”