A Comparative Study of the Direct and Residual Effect of Zinc Carriers on the Response of Crops in Calcareous Soil

In a field experiment conducted in a silt loam calcareous soil, the direct effect of zinc sulphate and zinc oxide was relatively better than zinc frits on barley. Similarly the available Zn in post-harvest soil samples was significantly higher in plots receiving the former two carriers than the latter one. The response due to zinc frits though was not so apparent on barley, the residual effect of it on the succeeding rice and wheat crops was quite distinct with respect to yields, Zn uptake and available Zn status of the soil. The availability of Zn from zinc frits progressively increased with time. Zinc oxide and zinc frits were found to have longer lasting effect than zinc sulphate.