氮磷添加对天童常绿阔叶林根际和非根际土壤碳氮库的影响

发布时间：2018-02-06 03:21

本文关键词： 氮添加磷添加根际土壤非根际土壤常绿阔叶林　出处：《华东师范大学》2017年硕士论文　论文类型：学位论文

【摘要】：根际通过根际活动影响植物生长、土壤环境,与植物根系发生着水分和养分的转换,使得根际和非根际土壤的养分特征存在较大的差异。氮磷添加后土壤养分状况改变,植物根系养分、生长及根际活动将受到影响,根际和非根际土壤的碳氮库特征以及与二者的差异也因此会发生改变。本研究选取浙江天童木荷林(Schima superba)氮磷添加样地,探究了氮磷添加对根际和非根际土壤碳氮库的影响。该样地设置4种施肥类型:对照(CK:0kgN/hm~2/yr)、氮添加(+N:100kgN/hm~2/yr)、磷添加(+P:50kgP/hm~2/yr)和氮磷添加(+NP:100kgN/hm~2/yr+50kgP/hm~2/yr)。研究开展了为期1年的季节性土壤取样,分析了不同施肥处理下根际和非根际土壤碳氮库的变化特征。结果如下:(1)氮磷添加对根际和非根际土壤碳库的影响不同处理下,不同季节根际土壤有机碳(SOC)、可溶性有机碳(DOC)、易分解有机碳(LOC)含量普遍大于非根际土壤,但LOC/SOC小于非根际土壤;对根际土壤而言,+N处理下DOC含量和LOC/SOC显著减小,但+P和+NP处理下DOC含量显著增加;对非根际土壤而言,+P处理显著增加了 SOC、DOC和LOC含量,显著降低了 LOC/SOC;+NP处理显著增加了 SOC和LOC含量;+N处理下根际和非根际土壤LOC/SOC的差异显著增大,+NP处理下根际和非根际SOC的差异显著减小。(2)氮磷添加对根际和非根际土壤氮库的影响不同处理下,不同季节根际土壤氮库各组分含量普遍大于非根际土壤;对根际土壤而言,+N处理下铵态氮(NH4+)含量显著增加,+P和+NP处理下全氮(TN)含量显著增加,+NP处理下NH4+和硝态氮(NO3-)含量显著增加;对非根际土壤而言,+N处理下NH4+含量显著降低,NO3-含量显著增加,+NP处理下TN和NO3-含量显著增加;+N和+P处理下根际和非根际土壤NH4+的差异显著增大,+NP处理下根际和非根际土壤TN、NH4+和可溶性氮(TSN)差异显著减小。总体而言,P添加比N添加对碳库的影响大,而N添加比P添加对氮库的影响大。
[Abstract]:Rhizosphere affects plant growth and soil environment through rhizosphere activities, and changes water and nutrients with plant roots. The nutrient characteristics of rhizosphere and non-rhizosphere soil are different. The soil nutrient status changes after nitrogen and phosphorus addition, plant root nutrient, growth and rhizosphere activities will be affected. The characteristics of carbon and nitrogen pool in rhizosphere and non-rhizosphere soil and their differences will also change. In this study, the nitrogen and phosphorus addition plots of Schima superba in Zhejiang Province were selected. The effects of nitrogen and phosphorus supplementation on carbon and nitrogen pool in rhizosphere and non-rhizosphere soil were investigated. Nitrogen added (N: 100kg / N / hmr 2 / yr). Phosphorus addition (P: 50kgP / hmmt2 / yr) and NP:100kgN/hm~2/yr (NP:100kgN/hm~2/yr 50kgP / hmmc2r). The study carried out a 1 year seasonal soil sampling. The changes of carbon and nitrogen pools in rhizosphere and non-rhizosphere soil under different fertilization treatments were analyzed. The results were as follows: 1) the effects of nitrogen and phosphorus addition on carbon pool in rhizosphere and non-rhizosphere soil were studied under different treatments. The content of organic carbon in rhizosphere soil was higher than that in non-rhizosphere soil, but LOC/SOC was lower than that in non-rhizosphere soil. For rhizosphere soil, DOC content and LOC/SOC content decreased significantly under N treatment, but DOC content increased significantly under P and NP treatments. For non-rhizosphere soils, P treatment significantly increased the content of DOC and LOC, and decreased LOC / SOC significantly. NP treatment significantly increased the contents of SOC and LOC. The difference of LOC/SOC between rhizosphere and non-rhizosphere soil increased significantly under N treatment. The difference of SOC between rhizosphere and non-rhizosphere under NP treatment was significantly reduced. 2) the effect of nitrogen and phosphorus addition on nitrogen pool in rhizosphere and non-rhizosphere soil was significantly decreased under different treatments. The content of nitrogen pool in rhizosphere soil in different seasons was higher than that in non-rhizosphere soil. For rhizosphere soil, the content of ammonium nitrogen (NH _ 4) increased significantly under N treatment, and the total nitrogen (TNN) content increased significantly under P and NP treatments. The contents of NH4 and NO3-nitrate increased significantly under NP treatment. For non-rhizosphere soil, the content of NH4 decreased significantly under N treatment, and the contents of TN and NO3- increased significantly under NP treatment. Under N and P treatments, the difference of NH4 between rhizosphere and non-rhizosphere soil was significantly increased, and TN in NP treated rhizosphere and non-rhizosphere soil was significantly increased. The difference between NH4 and TSNs was significantly decreased. In general, the effect of P addition on carbon pool was greater than that of N addition, and that of N addition was greater than that of P addition.
【学位授予单位】：华东师范大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S714

【参考文献】