Quantifizierung des Stickstoffs in Wurzeln und Wurzelausscheidungen von Soja

Summary

The below ground N allocation of organic soybean was examined in two experiments conducted in Eastern Austria. During early development, individual soybean plants were labelled with a 15N-enriched urea solution by the petiole-feeding method. The 15N enrichment of these plants and surrounding soil relative to their natural 15N abundance was determined at plant maturity. The proportion of soil N derived from roots was calculated from root and soil N isotope data. Total below ground plant N, including rhizodeposits, amounted to between 6 to 48 % of total plant N. The proportion of total plant N allocated below ground was inversely related to shoot N content.