淮北地区典型人工林地土壤氮磷形态及流失风险分析

发布时间：2018-05-23 23:34

本文选题：人工林地 + 土壤氮磷含量　；参考：《合肥工业大学》2017年硕士论文

【摘要】：以淮北地区蚌埠市怀远县古城镇某一人工林地为对象,在林地、林地排水沟渠采集及毗邻农田采集75个点位土壤样。在分析测试基础上,解析土壤氮磷赋存形态、有机质含量及其空间分布特征,分析土壤氮磷的生物有效性;通过相关性及差异性分析原理,剖析3种用地类型在氮磷含量和有机质、pH值等方面的相关性及差异性;采用氮磷指数法评估林地土壤氮磷流失风险,并在确定土壤磷素淋失临界值的基础上,识别土壤磷素淋失风险及高风险发生空间点位。主要研究成果概述如下:(1)林地土壤总氮和总磷平均值分别为1818.42mg·kg~(-1)和524.384mg·kg~(-1),有机质的范围为2.45%~8.86%,pH值分布于4.26~8.60,平均6.70,大致为中性土壤。与其他用地类型相比,林地土壤氮磷含量,有机质和酸碱度水平大致介于林地排水沟和农田之间。(2)林地土壤生物有效性氮和磷的平均含量分别为204.50mg·kg~(-1)和126.826mg·kg~(-1),分别占总氮和总磷的11.68%和25.73%,其中乔木林的生物有效性氮和磷的平均含量在林地土壤中最高;整个研究区内生物有效性氮、磷平均含量高低排序分别为农田林地排水沟林地、林地农田林地排水沟。(3)相关性分析结果表明,林地土壤三种氮形态之间均不相关,总磷与各形态磷之间相关性较显著,各形态氮磷与有机质、pH值之间也存在一定的相关性,林地土壤各污染指标之间的相关性优于林地排水沟和农田土壤。根据差异性分析结果,林地和农田之间的硝态氮、钙磷和有机质含量差异显著;林地和林地排水沟之间的有机质存在显著性差异,pH值在三者之间均有显著差异。(4)林地土壤氮、磷指数分别为2.79和3.48,氮流失以中等风险为主,磷流失以低风险为主。研究区土壤磷素的Fe/Al-P富集率较高,IP富集率较低,三种用地类型的Olsen-P临界值分别为64.909 mg·kg~(-1)、33.753 mg·kg~(-1)和37.423mg·kg~(-1),超过临界值的土壤样品占各自总样本数的比例分别为23.4%、31.3%和41.67%,相对风险系数平均值分别为0.173、0.426、0.274,林地的相对风险系数不高,低于林地排水沟和农田,因此林地土壤磷素淋失风险水平总体不高。
[Abstract]:Taking an artificial forest land in Huaiyuan County Huaibu City Huaibei area as an object 75 soil samples were collected from forestland drainage ditches and adjacent farmland. On the basis of analysis and test, the forms of soil nitrogen and phosphorus, the content of organic matter and its spatial distribution are analyzed, and the bioavailability of soil nitrogen and phosphorus is analyzed. The correlation and difference of nitrogen and phosphorus content and pH value of organic matter were analyzed, the risk of soil nitrogen and phosphorus loss was evaluated by nitrogen and phosphorus index method, and the critical value of soil phosphorus leaching was determined. Identify soil phosphorus leaching risk and high risk spatial location. The main results were summarized as follows: the average values of soil total nitrogen and total phosphorus in forest land were 1818.42mg kg ~ (-1) and 524.384mg ~ (-1), respectively, and the range of organic matter was 2.45 ~ 8.86 ~ 8.86 ~ 4.26 ~ 8.60 with an average of 6.70, which was approximately neutral soil. Compared with other land types, soil nitrogen and phosphorus content in forest land, The average contents of soil bioavailability nitrogen and phosphorus in forest land were 204.50mg kg ~ (-1) and 126.826mg ~ (1), which accounted for 11.68% and 25.73% of total nitrogen and phosphorus, respectively. The bioavailability of Arbor forest was about the same as that of Arbor forest, which was about 11.68% and 25.73% of total nitrogen and phosphorus, respectively. The average contents of nitrogen and phosphorus were the highest in the woodland soil. The results of correlation analysis showed that there was no correlation among the three nitrogen forms in the forest land, the order of the average nitrogen and phosphorus content in the whole study area was the drainage ditch of farmland forest land and the drainage ditch of forestland forest land, and the results showed that there was no correlation among the three nitrogen forms in the forest land. There was a significant correlation between total phosphorus and various forms of phosphorus. There was also a certain correlation between nitrogen and phosphorus forms and pH value of organic matter. The correlation between soil pollution indexes of forest land was better than that of drainage ditch and farmland soil. According to the results of difference analysis, there were significant differences in nitrate nitrogen, calcium and phosphorus and organic matter content between forestland and farmland, and significant difference in organic matter content between forestland and forestland drainage ditch. Phosphorus index was 2.79 and 3.48 respectively, nitrogen loss was mainly medium risk, phosphorus loss was mainly low risk. In the study area, the Fe/Al-P enrichment rate of phosphorus in soil is higher than that of IP, and the enrichment rate of IP is lower. The Olsen-P critical values of the three land use types were 64.909 mg / kg ~ (-1) and 33.753 mg / kg / kg ~ (-1), respectively. The proportion of soil samples above the critical value to the total samples was 23.443% and 41.67%, respectively. The average relative risk coefficient was 0.1730.4260.274, and the relative risk coefficient of forest land was not high. The risk of phosphorus leaching in forestland is lower than that in forestland gutter and farmland, so the risk level of phosphorus leaching in forestland is not high.
【学位授予单位】：合肥工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S714

【相似文献】