农业环境科学学报2012，Vol.31Issue(6)：1172-1179,8.
黄土丘陵区几种退耕还林地土壤固存碳氮效应
Soil Carbon and Nitrogen Sequestration Under Several Different Forest Lands Converted by Farmland in Loess Hilly Area
摘要
Abstract
This research was conducted lo determine the change of soil organic carbon and nitrogen in 0-60 cm soil layers under four types forested lands: Caragana, robinia, Chinese pine and orientals, which has been converted by farmland for 10 years and 30 years in loess hilly area. The results showed that, compared with sloped farmland, either content or density of soil organic carbon and nitrogen in different soil layers were significantly increased in Chinese pine and onentalis forest land after 10 years forestation. Compared with 10 years forestation, the soil organic carbon and nitrogen was further increased after 30 years forestation, with the order of organic carbon: onentalis >Chinese pine>robinia>caragana, and that organic carbon sequestration rate(0~60 cm soil layers) reached 1.06, 0.71, 0.43, 0.36 mgC·hm-2·a-1, respectively. In contrast, the rate of nitrogen sequestration was the highest by 0.051 mgN ·hm-2·a-1 under planting robinia, and was nol significantly different among other forest lands by 0.014-0.026 mgN ·hm-2·a-1. After the 30 years forestation, the soil organic carbon increased mainly from 0-20 cm soil layer with average contribution ratio of 51.9% under all forest land, and the soil nitrogen increased mainly from 40~ 60 cm deep soil layer with average contribution ratio of 42.5% in all forest land except for robinia. The ratio of C/N also increased in 0~20 cm soil layer under different forest lands. There was significant regression correlation between soil organic carbon and nitrogen. In summary, conversion of cropland to forest could sequestrate carbon and nitrogen in soil, from which, buckthorn and robinia were a better to improve soil organic carbon pool and soil nitrogen pool, respectively.关键词
退耕还林/土壤有机碳/土壤全氮/黄土丘陵区Key words
conversion of cropland to forest/ soil organic carbon/ soil total nitrogen/ loess hilly area分类
农业科技引用本文复制引用
韩新辉,杨改河,佟小刚,冯永忠,任广鑫,赵发珠,杜约翰..黄土丘陵区几种退耕还林地土壤固存碳氮效应[J].农业环境科学学报,2012,31(6):1172-1179,8.基金项目
国家自然科学基金(30971695) （30971695）
陕西省自然科学基础研究计划(2010JQ5001) （2010JQ5001）
教育部高等学校博士点基金(20090204120038) （20090204120038）
