喀斯特系统土壤厚度下土壤DOC淋失对氮沉降的响应

Response of Soil DOC Leaching to Nitrogen Deposition under Soil Thickness in Karst System

为研究喀斯特系统土壤DOC淋失在不同土壤厚度下对氮沉降的响应过程。以喀斯特石灰土为供试体,采用土柱淋溶法,试验设计3种不同土壤厚度(10、25、50cm)的淋溶管,淋溶管为PVC材质,直径20cm,选择3种不同氮沉降LN(191.08g/m^2)、MN(254.78g/m^2)、HN(318.47g/m^2),土表施予多年生黑麦草为研究对象。结果表明:氮沉降对土壤DOC淋失有一定的促进作用;土壤厚度对土壤DOC淋失有显著影响,土壤厚度越浅,氮沉降越大,DOC淋失越大,反之则越小。该研究可为解决喀斯特系统土壤碳循环问题与土壤质量评价提供一定参考和依据。

In order to study how the response of soil DOC leaching to nitrogen deposition under different soil thickness in karst system,using karst lime soil as the test sample,three different soil thickness(10 cm,25 cm,50 cm)leaching tubes were designed by soil column leaching method.The leaching tube was made of PVC material with a diameter of 20cm.Three different nitrogen depositions,LN(191.08 g/m^2),MN(254.78 g/m^2),and HN(318.47 g/m^2)were selected,and perennial ryegrass was applied to the soil surface.The results showed that nitrogen deposition had a certain effect on soil DOC leaching.Soil thickness had a significant effect on soil DOC leaching.The shallower the soil thickness,the larger the nitrogen deposition,the larger the DOC leaching loss,and vice versa.This study can provide some reference and basis for solving the soil carbon cycle problem and soil quality evaluation of karst system.