AbstractTwo-year field investigations were conducted in West Bengal, India, to evaluate the zinc (Zn) and iron (Fe) sequestration potential of five diverse rice cultivars (IR 64, Satabdi, MTU 1010, GB 1 and KRH 2) under conventional and system of rice intensification (SRI) cultivation methods. The study also assessed the influence of Zn fertilization (basal and foliar) and farmyard manure (FYM) application on yield, yield-attributing traits and micronutrient content in grain and straw. Results showed that the conventional system generally outperformed SRI in plant height, panicle-bearing tillers, straw yield, grain yield and both grain and straw Zn and Fe concentrations. This might be attributed to altered Zn adsorption-desorption kinetics and reduced transpiration rates under SRI’s alternate wetting-drying conditions. Zinc fertilization significantly increased plant height, tiller number and both straw and grain yields (up to 24.76% in grain yield) across both systems. It also substantially increased Zn content in rice grain (up to 25.32%) and straw, with FYM further enhancing grain Zn loading. However, a critical finding was the significant reduction in Fe content (up to 9.01%) in both grain and straw due to Zn fertilization, indicating an antagonistic interaction between these two essential micronutrients. This antagonism likely arises from competition during root absorption, xylem loading and transport within the plant. These findings underscore the effectiveness of Zn fertilization for yield enhancement and Zn biofortification in rice. However, they also highlight the challenge of concurrent Fe depletion. Future breeding and management strategies should, therefore, aim to identify or develop rice cultivars that can maintain or enhance both Zn and Fe accumulation, particularly when cultivated under varying water management regimes, to effectively address the global micronutrient malnutrition challenge.
Biplab Pal (Wed,) studied this question.