渭北旱塬不同树龄果园土壤营养状况演化趋势

[目的]为了探明果园土壤质量的演化趋势,探讨果树可持续生产的理论基础。[方法]对渭北旱塬不同树龄果园土壤有机质、有效氮、速效磷以及钙的剖面分布特征和变异状况进行了研究分析。[结果]研究得出,果园土壤深层有机质含量显著降低,8~15龄果树的果园土壤有机质随生长年限的增加而减少;不同园龄土壤在40 cm以上土层有效氮和速效磷含量尽管有所增加,但氮和磷的供给能力仍在中下等水平;即使在富钙的石灰性土壤果园里,其土壤上层交换性钙含量变化幅度不大,而60 cm以下土壤交换性钙明显递减,土壤剖面有酸化趋势。[结论]渭北地区果园养分管理的关键问题在于施肥深度欠佳,旱塬地区土壤墒情欠缺的情况下,必须适度深施肥料,才能充分发挥肥效。

Research on the Evolution Trend of Soil Nutrient of Different Tree Ages in Weibei Dry Plateau

[Objective] The evolution tendency of the orchard soil quality was verified and the theoretical basis of sustainable fruit tree production was discussed.[Method] The distribution characteristics of soil organic matter,available N,available P and Ca in soil profile on orchard of different tree ages in Weibei Dry Plateau were analyzed and studied.[Results]The results showed that the content of organic material in orchard soil in-depth was obviously reduced.With the age-increasing of the tree from 8-15 tree ages,the content of organic matter in orchard soil was reduced.Even though the available N and available P above 40 cm layers in the soil with different orchard ages were slightly increased,the capacity of N and P-providing was not high.The variation of exchangeable calcium content in soil upper layers was not obvious in the calcareous orchard soil which was rich in calcium.There was obvious reduction trendy in the exchangeable calcium content under 60 cm soil layers,which showed there was an acidification trend in soil.[Conclusion] In the Weibei area the key issue of nutrient management in orchard is the poor fertilization in depth dryland.Under the bad soil condition, the fertilizer efficiency could be given full play in the moderate deep fertilization.