Effect of tillage and weed management practices on soil micronutrients availability in post-harvest under aerobic rice-wheat cropping system

The present investigation was carried out at the Research Farm of the Department of Agronomy, CSKHPKV, Palampur during the kharif 2022 to rabi 2023-24 seasons, as part of an ongoing long-term experiment initiated in 2013-14. The study comprised fifteen treatment combinations involving five tillage practices CT-CT, CT-ZT+R, ZT-ZT, ZT-ZT+R, and ZT+R-ZT+R (CT: conventional tillage; ZT: zero tillage; ZT+R: zero tillage with residue retention) and three weed management strategies H-H (herbicide), IWM-IWM (integrated weed management), and HW-HW (hand weeding) within an aerobic rice-wheat cropping system. The experimental soil was silty clay loam in texture, classified under the Alfisol order and Typic Hapludalf subgroup. Post-harvest soil samples were collected from a 0-15 cm depth following wheat harvests in 2022-23 and 2023-24 and analyzed for chemical properties, particularly micronutrient availability. The treatment involving zero tillage with crop residue retention in both rice and wheat (ZT+R-ZT+R) significantly enhanced the availability of micronutrients such as Cu, Fe, Mn, and Zn. In contrast, the conventional tillage system for both crops (CT-CT) recorded the lowest levels of these micronutrients. Among weed management practices, significant differences were observed in DTPA-extractable Fe and Zn content, whereas Cu content remained unaffected.