Nutrient uptake differences of Jun jujube in different ages

【Objectives】 The objective of this study was to clarify the differences of Jun jujube in annual nutrient demands for the production of unit fruit yield in different tree ages.【Methods】Samples of the 4, 7 and 10-year’s old Jun jujube trees in Aksu Area were tested for the N, P, K, Ca, Mg, Mn, Fe, Zn and Cu contents in aboveground organs, and a proposal was put forwarded in the practical fertilization of the Jun jujube.【Results】There are no significant differences in the nutrient contents in the same organs of Jun jujube trees of different ages, but there are some differences in the percentages of the aboveground organs’ biomass to their total biomass. For the 4, 7 and 10 years’ old jujube trees, the percentages of the fruits in the total biomass are 72.9%, 73.7% and 75.7%, those of leaves are 5.4%, 5.2% and 5.1%, those of flowers are 1.3%, 1.5% and 1.4%, and those of stems are 19.5%, 20.4% and 17.8%, respectively. The biomass with all the 3 ages are in order of fruits stems leaves flowers. As the age increasing, the total biomass required for the production of 1000 kg fruits are increased gradually, the preharvest dropping ratios of fruit are increased, the leaf biomass are decreased, the retained flower biomass shows an upward trends, the dropping flower biomass is first increased and then decreased, and the biomass of pruned and retained stems and branches are also reduced. The orders of nutrient element contents required for growth of the aboveground organs in the three ages of Jun jujube trees are K N Ca Mg P Fe Zn Mn Cu. The nutrient amounts for 1000 kg fruit production in 4 year’s old Jun jujube are N 22.8 kg, P 1.7 kg, K 34.0 kg, Ca 7.5 kg, Mg 5.0 kg, Mn 54.5 g, Fe 916.9 g, Zn 202.8 g, Cu 42.5 g; in 7 year’s old trees are N 22.7 kg, P 1.7 kg, K 33.9 kg, Ca 7.3 kg, Mg 4.9 kg, Mn 53.9 g, Fe 907.2 g, Zn 204.5 g, Cu 42.0 g; and in 10year’s tree are N 22.1 kg, P 1.7 kg, K 33.4 kg, Ca 6.8 kg, Mg 4.7 kg, Mn 51.8 g, Fe 871.3 g, Zn 204.8 g, Cu 40.4 g. 【Conclusions】The ratios of fruit biomass to other aboveground organs’ total biomass in all the three tested ages of Jun jujube trees are about 3∶1. The nutrient uptakes for the 1000 kg of fruit production are almost the same. As the total biomass and fruit yield are increased with the age of trees, which leads to higher nutrient requirement. As the increase of the percentage of fruit in total biomass, the total nutrient requirement should be considered including the other organs’ nutrients uptake.