中文摘要：

针对我国北方典型潮土区苗圃育苗过程中水肥利用效率不高的现状,选取北京市昌平区速生杨种苗培育基地为研究对象,开展不同施肥处理条件下0-100cm土壤剖面氮素养分垂向运移过程的田间定位监测试验。监测结果表明,3种施肥处理条件下的0-100cm土壤剖面中各土层硝态氮含量以表层土体为最高,由表层向底层土壤硝态氮含量呈逐渐减小的趋势,其中处理3条件下0-100cm土壤剖面中硝态氮含量均高于处理1条件和处理2条件下的;0-100cm土壤剖面硝态氮平均累积总量排序依次为处理3〉处理2〉处理1,其中处理3条件下土壤硝态氮平均累积总量高达307.85kg/hm2,表明过量施肥导致土壤中硝态氮大量累积,使得硝态氮极易随土壤渗漏水下移淋失。研究结果进一步揭示了北方典型潮土土壤水、硝态氮淋失的垂向迁移与渗漏损失机制,可为制定科学的苗木施肥方案、提高肥料的利用效率、完善林木抚育管理技术等提供有力的理论支撑和科学指导。

英文摘要：

According to the current status of the lower use efficiency of water and fertilizer on seedling cultivation in typical alluvial soil district of northern China,the seedling fostering base of fast-growing poplar in Changping district of Beijing was chosen as the research object in this paper.Field location monitoring experiments were carried out to study the vertical transport process of soil nitrate nitrogen in 0-100 cm soil profile under various fertilizer treatments.Monitoring results indicated that soil nitrate nitrogen content in the surface soil was higher than that of the other soil layers in 0-100 cm soil profile under three fertilizer treatments.Soil nitrate nitrogen content reduced gradually with the depth of soil profile and soil nitrate nitrogen content with treatment 3 was higher than those of treatment 1 and treatment 2.The average amount of nitrate nitrogen of 0-100 cm soil profile from high to low could be ordered as： Treatment 3 treatment 2 treatment 1.Among them,the average amount of nitrate nitrogen of 0-100 cm soil profile with treatment 3 was up to 307.856 kg/hm2.This showed that excessive fertilization led to nitrate nitrogen accumulation in the soil profile and it also increased the risk of nitrogen leaching loss by soil percolating water.Research results can reveal the mechanism of soil water and nitrate nitrogen vertical transport and leakage loss.This paper is helpful to provide powerful theoretical support and scientific guidance for making scientific fertilization scheme of seedlings,increasing fertilizer use efficiency and improving forest tending and management technology.