Response of rice to zinc fertilizer in calcareous soils

Three greenhouse experiments were conducted to study the response of rice crop to zinc fertilizer under waterlogged conditions using 65Zn-labelled ZnSO4 in 30 calcareous soils of North Bihar and Punjab having 2 to 36 per cent free CaCO3 content. Application of 5 kg Zn/ha gave significant increase in drymatter yield, total Zn content of rice in the first experiment. The soils differed significantly in drymatter yield, total Zn content, per cent Zn derived from fertilizer (Zndff) and Zn utilization by rice. Application of 5 ton/ha compost with 5 kg Zn/ha gave significantly higher drymatter production over 5 kg Zn/ha treatment but the total Zn content of plant showed significant reduction due to compost application. The per cent Zndff and utilization of Zn by rice remained at par in both the treatments. The soils differed significantly with respect to these characters as well as in the total Zn content in drymatter. The residual effect of Zn fertilizer treatments on the drymatter yield, per cent Zndff and Zn utilization by wheat crop did not differ significantly. The Zn content of wheat showed significant depression due to compost application along with Zn. (author). 11 refs., 3 tabs