Effects of different nitrogen-fertilizers on the rhizosphere biochemistry of winter wheat (Triticum aestivum) var. Fredrick.

Abstract

Wheat growth appeared to be similar with the different N-fertilizers. However, a tendency for more growth was observed under nitrate and a mixed nutrition. The supply of ammonium, a mixture of ammonium and nitrate or urea resulted in an acidic pH in the rhizosphere. Nitrate uptake by plants resulted in a pH increase of the rhizosphere. The amounts and types of amino acids in the rhizosphere were significantly (P 0.05) different under the various N-fertilizers. In the wheat rhizosphere supplied with nitrate the total amino acids were less than those of plants supplied with the other N-fertilizers. The greatest total amount was observed under ammonium supply. In the case of nitrate-fed plants there were more basic amino acids in the rhizosphere whereas, plants supplied with other N-fertilizers exuded more acidic amino acids. The amount of amino acids decreased with time. The different forms of N-fertilizers also produced different effects on the amounts and types of both soluble and insoluble sugars in the rhizosphere. (Abstract shortened by UMI.)