Effect of levels of zinc and iron and their chelation on yield and soil micronutrient status in hybrid rice (Oryza sativa)-wheat (Triticum aestivum) cropping system

A field experiment was conducted during rainy and winter seasons of 1999–2000 and 2000–2001 to evaluate the levels and mode of application of zinc and iron on grain yields of hybrid rice (Oryza sativa L.) and wheat (Triticum aestivum L. emend. Fiori & Paol.) crops and also the changes taking place in the micronutrient status in the soil. The levels and mode of application of zinc and iron considerably increased the growth, yield attributes and yield of rice-wheat cropping system and also improved the soil status of these micronutrients after harvest of each crop over the control. Application of 30 kg ZnSO₄+ 5 kg FeSO₄/ha through chelating with FYM was found to be the best combination for rice. However for hybrid rice-wheat cropping system, application of 40 kg ZnSO₄ + 10 kg FeSO₄ was found to be the most appropriate combination to maximize the grain yields of this system and improve the zinc and iron status of soil.