Natural 15N Abundance in Winter Wheat Amended with Urea and Compost: A Long-Term Experiment

Abstract We investigated 15 N abundance (δ 15 N) of winter wheat ( Triticum aestivum cv. Jinmai 1) plants and soil at different growth stages in a field with a 13-year fertilization history of urea and compost, to determine whether or not the δ 15 N of plant parts can be used as an indicator of organic amendment with compost. Plant parts (roots, leaves, stems and grains) and soil were sampled at re-greening, jointing, grain filling and mature growth stages of winter wheat. There were significant differences between the urea and compost treatments in δ 15 N of whole plants, plant parts and soil over the whole growing season. Determination of the δ 15 N of plant parts was more convenient than that of whole plant to distinguish between the application of organic amendment and synthetic N fertilizer.