ZINC STATUS OF PADDY SOILS OF MALAYSIA IN RELATION TO SOME PHYSICO-CHEMCAL PROPERTIES

Abstract

The micronutrient zinc is required by rice in a small quantity, but its deficiency has an adverse effect on healthy crop growth and the yield may decrease up to 30%. The states of Kedah and Kelantan of Malaysia are the main paddy growing areas of the country. Fifteen soil series from these states were selected for the determination of Zn²⁺, Cu²⁺, Mn²⁺ and Fe²⁺ status and some other physico-chemical properties. Soil samples were collected from three different locations of same soil series at the depths of 0-15, 15-30 and 30-45 cm. All the soils were acidic and low in organic carbon and P, while their texture varied from clay loam to silty clay. Copper (Cu²⁺) and manganese (Mn²⁺) were moderate in status, and iron was high. Available soil Zn²⁺ varied at different depths and locations for all the soil series (P<0.05); the top soils contained as high as 2.03 mg kg^-1 and the subsoils as low as 0.22 mg kg^-1. Zinc concentration had negative correlation with Cu²⁺ (r= -0.77*), P (r= -0.65*), Fe²⁺ (r= -0.54*), Mn²⁺ (r= -0.23*) and pH (r= -0.21*) and positive correlation with organic carbon (r = 0.41). This study shows that Zn²⁺, Cu²⁺, Mn²⁺ and P status  of paddy growing soils of Malaysia is low, and this could possibly be one of the main reasons of low rice yield.