炼山和遮阳网覆盖对马尾松人工林土壤全氮及矿质氮格局的影响

Effects of Controlled Burning and Sun-shading Net Covering on Soil Total Nitrogen and Mineral Nitrogen in Pinus massoniana Plantations

以炼山和不炼山马尾松人工林采伐迹地为研究对象,采用遮阳网地表覆盖的方法,在炼山后覆盖60,150,300d动态采集不同土层的土壤样品,研究土壤全氮和矿质氮及其格局的动态过程。结果表明:炼山表现出降低土壤全氮含量的趋势,但能显著增加覆盖60d和150d铵态氮和硝态氮的含量。遮阳网覆盖可以一定程度上改善炼山对土壤全氮含量的减小趋势,且明显增加炼山环境下土壤铵态氮和硝态氮含量,在炼山和覆盖60d和150d内保肥作用明显。相对于遮光率100%的遮阳网,遮光率85%的遮阳网覆盖可以更为有效地促进土壤矿质氮的增加;同时,炼山和遮阳网覆盖显著改变并提高土壤矿质氮占全氮的百分比。

Taking Pinus massoniana plantations with and without controlled-burning as the research object, using sun-shading nets in broadcast burning and covering after 60 days, 150 days and 300 days, soil samples in three different layers were collected to study the soil total nitrogen and soil mineral nitrogen dynamic process and pattern of dynamic. The results showed that controlled burning reduced the total nitrogen content of soil, but it could significantly increase soil ammonium nitrogen and nitrate nitrogen content in the burning after 60 days and 150 days, sun-shading net covering could significantly increase soil ammonium nitrogen and nitrate nitrogen content in the burning condition. There was obvious fertilizer retention effect in controlled burning and covering 60 days and 150 days. With respect to the shading rate of 100% sun-shading net, shading rate of 85 ; sun-shading net promoted more effectively to increase soil mineral nitrogen. At the same time, controlled burning and sun-shading net covering significantly increased the percentage of soil mineral nitrogen and soil total nitrogen.