Study on nitrogen absorption, utilization and accumulation in grape tree

Aim to find out the nitrogen absorption, utilization and accumulation in grape tree, and to provide a reasonable fertilizer rate and application periods, field experiments were conducted to analyze the yearly biomass, nitrogen content and its accumulation at different parts of grape tree (Red globe), which are cultivated about 7 years. The results show that yearly biomass increase is about 12369 kg/ha. Nitrogen content order in the organs was: leaves>fruits> new branches> roots> branches>stems. Nitrogen content of cortex is larger than that of xylem. Total nitrogen absorption rate is 97.1 kg/ha in one year of the growing period, in which 39% is absorbed during the new shoots flourishing period and 30.5% for fruit growing period. To attain 1000 kg economic yield, grape tree should uptake N 5.4 kg. Nitrogen carried off by leaves, fruits and pruned branches were 35.09, 32.27 and 5.11 kg/ha, about 36 %，33 % and 5 % of the gross, respectively. Nitrogen loss carried away by leaves, fruits and pruned branches should be made up by fertilization.