Evaluation of amounts, methods and sources of zinc application to wheat in flood plain soils

Abstract

SUMMARYField experiments were conducted in a zinc-deficient flood plain alluvial soil to study the effect of amounts, methods and sources of zinc application on the yield and uptake of zinc by wheat. Zinc was applied at 0, 5 and 10 kg Zn/ha as zinc sulphate and zinc oxide either broadcast and mixed in the soil or drilled below the seed. Spray application of zinc was also tested. Irrespective of the source, grain yield and zinc uptake significantly increased up to 10 kg Zn/ha. Soil-applied zinc was highly correlated with yield and zinc uptake in the two field experiments. Grain yield was also found to be significantly correlated with zinc content of grain (r = 0·78), straw (r = 0·72) and flag leaf (r = 0·66). When applied at the rate of 10 kg Zn/ha, broadcasting of zinc sulphate and drilling of ZnO below the seed were equally effective in increasing grain yield of wheat. Foliar spray of zinc sulphate was an effective emergency method, but in highly zinc-deficient soils it did not compare well with soil application of zinc.