Management of zinc fertilizer under pearl millet–wheat cropping system in a typic ustipsamment

Field experiments were conducted with pearl millet-wheat cropping system on a Typic Ustipsamment to assess the direct, residual and cumulative effect of Zn application on crops with or without use of organic manure. The residual effect of 10 kg Zn ha⁻¹ applied to first crop on grain yields was noted up to the sixth crop. Better yields were obtained with the application of 10 kg Zn ha⁻¹ every year or at least in alternate years. Combined application of 2.5 kg Zn + 5 t FYM ha⁻¹ in alternate years gave significantly higher concentration of Zn in flag leaf, its uptake by crops and higher content of DTPA-extractable Zn in soil at the end of three years’ cycle. Apparent Zn fertilizer use efficiency under combined application of 2.5 kg Zn + 5 t FYM ha⁻¹ applied in 1^st and 2^nd years or 1^st and 3^rd years was about ten-fold higher than application of 10 kg Zn as ZnSO₄ ha⁻¹ in 1^st and 2^nd or in 1^st and 3^rd years.