Conservation Tillage and In-Situ Rice Residue Driven soil Temperature Moderation and Wheat Productivity under Terminal Heat Stress in North-Western Indo Gangetic Plains of India

Rice-wheat cropping system facing serious issues in terms of scarcity of resources (water, labour, land and energy), escalating cultivation cost coupled with frequent climatic anomalies in South Asia. Generally, farmers following in-situ burning for easy disposal off of rice residue and timely seeding of succeeding wheat crop. Timely sowing of wheat under full rice residue load has become possible with the help of efficient seeding machineries. Therefore, an experiment was conducted to study soil temperature fluctuation, weed dynamics and crop productivity under different tillage and rice residue management options in wheat during rabi 2020-21 and 2021-22. Zero tillage with rice residue showed thermo-moderating effect by lowering afternoon soil temperature by 1.8 to 3.59 ℃ and 0.88 to 4.66 ℃ under normal (2020-21) and terminal heat stress (2021-22) conditions, respectively compared to conventional till wheat from 5 to 14^th standard meteorological weeks. Lower soil temperature found under zero tillage scenario compared to conventional tillage and difference was more pronounced in heat stress conditions. This congenial environment also reflected in wheat yields as zero till wheat under full rice residue retention with (4891–5238 kg/ha) and without waste decomposer (4950–5264 kg/ha) resulted in higher grain yields as compared to conventional till wheat (3740–4244 kg/ha). Sowing of wheat under residual soil moisture (irrigation is to be applied 10–14 days before super straw management based combine harvesting of rice) and residue driven reduction in soil temperature may facilitate early sowing and moderating soil temperature against terminal heat stress, besides saving of pre-sowing irrigation in wheat.