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以7年生嘎拉苹果/平邑甜茶为试材,利用15N示踪技术,研究了苹果生产体系中氮素年周期的利用、残留、损失及在土壤中的迁移动态。结果表明,对春季土施尿素的利用率盛花期较低,为11.38%,至采收后达到最高。土壤氮素残留率盛花期最高,为57.10%,果实采后残留率最低。年周期中各土层氮素残留量不同,盛花期20～40cm土层残留量最高,采收后最低,0～20cm土层在新梢旺长期残留量最高,果实成熟期最低,而40～60cm土层在果实膨大期残留量达到最高,在采收后0～20cm土层残留有所增加,其余各土层残留量均达到最低值。氮素损失与土壤残留呈相反的变化趋势,氮素损失率在盛花期最低为31.53%,随物候期的推迟逐渐升高,在果实采后高达58.40%。
Using 7-year-old Gala apple / Phyllostachys praecox as test material, the 15N tracing technique was used to study the annual nitrogen utilization, residuals, losses and the dynamics of migration in the soil of apple production system. The results showed that the utilization of spring soil urea was low at 11.38%, reaching the highest after harvest. Soil nitrogen residual rate of the highest flowering, was 57.10%, fruit postharvest residue rate lowest. The annual residual nitrogen content of different soil layers was the highest in the 20-40 cm soil layer during the full bloom period and lowest after harvesting. The soil residues in the 0-20 cm soil layer had the highest residues in the shoots and the lowest fruit ripening stage, The residue of 60cm soil layer reaches the maximum in the period of fruit enlargement, and the residue in 0 ~ 20cm soil layer increases after harvesting, while the rest of soil layers reach the minimum value. The nitrogen loss showed the opposite trend with the soil residue. The lowest nitrogen loss rate was 31.53% in full flowering stage and gradually increased with the postponement of the phenological stage, reaching as high as 58.40% after harvesting.