Availbale zinc, copper, iron and manganese status of the acid rice soils of Kuttanad, Kerala state

Abstract

Determination of available zinc, copper, iron and exchangeable manganese in the [Cari, Karapadom and Kayal soils of Kuttanad region, Kerala State, revealed that all the three soil types are highly deficient in available copper (90%). Available zinc was deficient in 50% of the Kayal soils studied. High amounts of available iron in the Kari soils suggest the possibility of iron toxicity to rice in these soils. Significant and positive correlations existed between available copper on the one hand and organic carbon (r= + 0.400) and CEC (r= + 0.566! on the other. Available iron was significantly and positively correlated with organic carbon (r= +0689) and CEC (r= -f 0.566) and significantly and negatively correlated with pi! (r= - 0.425) and exchangeable Ca + Mg (r= - 0.408). The results warrant application of copper in all the three types of Kuttanad soils and of zinc in the Kayal soils.