¹⁵N Distribution in Wheat and Chemical Fractionation of Root-Borne¹⁵N in the Soil

Abstract

Abstract Spring wheat plants were grown in split-root containers and labelled with 15N by fertilizing one compartment of the container with 15NH4 15NO3 (95 at.-% 15N exc.). After the harvest, approx. 90% of the 15N incorporated by the plants were found in the shoots and 3% in the roots; approx. 7% had been released into the soil of the unlabelled compartment. The 15N in the soil of the unlabelled compartment was extracted with KCl and hydrolysed with HCl. Approx. 60% of the 15N was found in the hydrolysable organic N pool of the soil and 9% in the fraction of the soluble and exchangeable inorganic nitrogen.