Effects of nitrogen sources and copper levels on yield, nitrogen and copper contents of wheat (Triticum aestivum L.)

Abstract

A pot experiment was conducted, in a greenhouse, at Hisar, India, using a sandy soil deficient in nitrogen and copper, to study the effects of various levels of N and Cu on the dry matter yield and the N and Cu contents of wheat (Triticum aestivum L.). The sources of nitrogen used were Ca(NO3)2, NH4Cl and NH4NO3 applied in amounts necessary to establish 120 ppm of soil nitrogen and using a control (0 ppm N). Copper was applied, as copper chloride, to give soil Cu levels of 0, 5, 10 and 20 ppm. In general, dry matter yields, N and Cu concentrations in shoots and roots and available soil-N after harvest of the plants, followed the order Ca(NO3)>NH4NO3>NH4Cl. Up to a level of 5 ppm Cu, the dry matter yields of shoots and roots increased, but decreased at higher levels of Cu. Increasing Cu levels significantly decreased the available soil-nitrogen after harvest and also the concentration of N in the plants. At the same time the concentration of Cu in shoots and roots and available Cu in the soil was increased. Nitrogen and copper were found to have a mutually antagonistic effect on each other's concentration in the plants. The antagonism was greater with NH4 + sources than with NO3 − compounds.