| Using the stable isotope 15N-labelled urea the experiment was carried out in Shandong Binzhou research institute of winter jujube from 2002 to 2005. The characteristics of 15N absorption, distribution and remobilisation in different fertilizer stages under the condition of pot cultivation and the distribution of nitrogen from urea applied to different type of shoots leaves during fruit development period and post-haverst in the field experiment were studied. The main results were as follows:1. All the treatment contributed to building up N in the perennial woody organs, but fruit core-hardening stage treatment was very helpful to increase tree N storage and its partitioning to new growth organs. The largest amounts of 15N were detected in the roots and trunks in the winter. With the delay of 15N-urea application time, 15N increased the partitioning to roots. Coarse roots were the'long-term sink'of N storage in the growth of winter jujube trees. FCH and FRS treatment resulted in the similarly N partitioning into the organs of winter jujubes trees.2. The largest amount of 15N was detected in the roots and trunks in winter. In all treatment the partition rates were highest in coarse roots. 15N stored in roots and trunks were used by jujube trees to sustain new growth in the following full bloom. 15N applied before budding resulted in lower Ndff% in perennial organs (trunks and coarse roots) sampled in the following full bloom, but fine roots had highest Ndff% (1.28%). Other organs recovered similar amount of Ndff%. In contrast, fruit core-hardening stage and fruit rapid-swelling stage treatment led to higher Ndff%(4.01~5.25%) in the new growth organs (new growth branches, deciduous spurs, leaves and followers), but lower in perennial branches(1.49~2.89%).With the delay of 15N-urea...
|
PDF Full Text Request