Effect of applied. phosphorus, sulphur and zinc on yield and uptake parameters of wheat(Triticum aestivum) and soybean (Glycine max) grown on a loamy sand

Abstract

A study iiilllS conducted during 1995-96 on the effect of phosphorus, sulphur and zinc application on yield and uptake parameters of creps, a greenhouse experiment on wheat (Triticum ueativum L. emend. Fiori & Paol.) and. soybean [Glycine max(L,) Mm.] on Typic Ustochrept(Inceptisol) with 4 levels ofP (0,13.4,26.8 and40.2rogPlkg) and S (0, 4.46,8.92 and 13.38 rug Slkg) and 2 of Zn (0 and 12.7 mg Zn/kg). ChemiCally pure salts were used as the sources of nutrients and the crops were irrigated with distilled water. The crops were harvested at maturity and plant samples were analysed for nutrient uptake following di-acid digestion. Ailalysis ofvariance was carried out ~ing split plot design. Uptake ofN, P and S was significantly enhanced by appliedP and S in botJi"wheat and soybean crops. Phosphorus applied at 26.8 and 40.2 mg P/kg and S applied at all levels increased the grain of soybean but Zn had no eff~. Application ofS @8.92 and 13.38 mg/kg also increased the oil content in soybean grain. The most effective combinations appeared to be 40.2 mg P along with 13.38 mg Slkg for grain yield of wheat, 26.8 mg P along with 13.38 rug S/kg for grain yield of soybean, and 8.92 rog S/kg for oil content in soybean grain. A dose of26.& mg P and 8.92 mg S preferably with 12.7 mg Znlkg soil appeared to be optimum for overall yield and quality ofwbeat and soybean crops.