Effects of root nutritional space on absorption,transportation and distribution of nitrogen in 'Fuji' apple trees

摘要

The young trees of Malus.domestica Borkh. cv. Red Fuji/M.hupenensis Rehd were used in the experiment to study efficiency of partial treatment with nitrogen fertilizer. The results showed that there existed optimal N-nutrition space and N reserve of bio-effects in the root system of trees. Numerical values of bio-effects changed with the level of fertilized nitrogen. In absence of N, the apple tree supplied leaves with N first. The N-content in roots increased with applied N, however, decreased if continuing to fertilize N. When N was given excessively, the N-level in leaves and roots decreased relatively because of the quick growth of aboveground parts of the tree.