Response of rice (Oryza sativa) to zinc sulphate incubated and blended with organic materials in sodic soil

In a field experiment on rice (Oryza sativa L.) in sodic soil, ZnSO4 @ 20 a nd 30 kg/ha incubated and blended separately with pressmud and farmyard man ure (each at 0.25 tonne/ha) was compared with the recommended dose of 40 kg /ha alone. Zinc sulphate at 20 kg/ha incubated or blended either with press mud or farmyard mannre was at par with ZnSO4 at 40 kg/ha alone in respect o f grain and straw yields of rice and N and Zn contents and their uptake by the crop. incubation or blending of ZnSO4 at 20 kg/ha with either of the or ganic materials also maintained almost equal amounts of available Zn in soi l and recorded high recovery of applied Zn compared with ZnSO4 at 40 kg/ha alone. Further, high available P in soil and hence in plants caused signifi cantly more uptake of P with ZnSO4 at 20 kg/ha incubated or blended with ei ther of the organic materials than ZnSO4 at 40 kg/ha alone. Thus, by incuba tion or blending of ZnSO4 at 20 kg/ha prior to its incorporation into the s oil under rice, 50% of the recommended dose of ZnSO4 may be saved.