The decline in the availability to plants of applied copper fertilizer

Abstract

The availability of copper sulfate for uptake by wheat plants declined linearly with time over 13 years of contact between the soil and the applied copper for a yellow brown lateritic sandy earth in a semiarid mediterranean environment. A steady decline in both the copper concentrations of the youngest emerged blade (YEB) and copper content in shoots of wheat plants resulted with increasing time of soil contact. For all copper additions, a linear model was fitted to the decline in YEB copper concentrations with time. This model predicts that copper deficiency would be observed 18, 30 and 44 years after the application of the 2.75, 5.5 and 8.25 kg copper sulfate/ha at this site.