Frequency and Rates of Zinc Application under Hybrid Rice – Wheat Sequence in a Mollisol of Uttarakhand

Field experiments were conducted on a Typic Hapludoll to evaluate the efficacy of different rates and frequency of Zinc (Zn) application on yield, zinc concentration and uptake of hybrid rice-wheat sequence. Zinc application significantly increased the grain yield, concentration in as well as uptake by both the crops. The concentration of Zn was more in wheat grain as compared to straw while the reverse was true for rice; however, total zinc removal by hybrid rice was more than twice as compared to wheat. Application of zinc sulphate significantly increased the DTPA-extractable Zn in soil but the effect decreased with subsequent crop removal. Evaluation of different rates and frequencies of Zn clearly indicated that application of 10 kg Zn ha−1 to rice in the first year and 5 kg Zn ha−1 to rice in the second year was most economical combination to sustain the productivity of hybrid rice-wheat sequence in the tarai region of Uttarakhand.