Correlation of Available Copper Values Obtained By Different Methods to Copper Uptake by Maize

Abstract

For determining the availability of copper in soils of Tarai region of U. P., extractions were made from 10 different soils of this region by five different reagents viz. (a) Water, (b) 0.1 HOI, (c) 0.05 M EDAT, (d) N ammonium acetate (pH 4.6, and (e) N ammonium acetate (pH 7.0). Maize plants were grown in pots containing all significant correlations between neutral ammonium acetate (r=+0.812) and 0.05 M EDTA (r=o+0.993) extractable copper and copper uptake by maize plants were obtained. Simple correlation coefficients were also worked out between each of several soil factors and extractable copper. The results showed no significant correlation of extractable copper with soil pH, clay, organic matter and calcium carbonate except between neutral ammonium acetate extractable copper and per cent clay in soil.