Soil C, N, and P Stocks Evaluation Under Major Land Uses on China's Loess Plateau
Soil C, N, and P Stocks Evaluation Under Major Land Uses on China's Loess Plateau
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中国黄土高原主要土地利用方式土壤C、N、P库评价
DOI：
10.1016/j.rama.2016.10.005
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发表时间：
2017-05-01
影响因子：
2.3
通讯作者：
He, Xiongzhao
中科院分区：
文献类型：
--
作者：
Chen, Xianjiang;Hou, Fujiang;He, Xiongzhao
黄土高原位于中国北方中部，面积64万km。尽管半干旱的环境，严酷的冬季和炎热的夏季，农业已经在这个地区实行了超过5000年，粮食生产系统是中国最古老的。由于黄土性土壤易受侵蚀，环境十分脆弱。因此，需要可靠的科学信息来支持该区域未来的土地使用规划。为此，土壤有机碳（SOC），氮，磷储量测定在更广泛的黄土高原环县，代表5个主要土地利用类型。在3年内对研究中心进行了3次采样。总共进行了近2800项土壤分析。这些土壤的一个特点是低SOC含量在A层，但相对较小的下降随土壤深度。例如，0-20 cm和70-100 cm土壤深度的有机碳水平平均分别为6.1和4.1 Mg ha（-1）。在100 cm土层中，盐碱地和草地的土壤有机碳总量比农田多5.1兆公顷（10%），比两个林草地的土壤有机碳总量多7.5吨公顷（16%）。对于土壤总氮（0- 100厘米土壤深度）的平均值苜蓿和RL网站分别为20%和28%，高于农田和森林牧场网站组的手段，虽然土壤C，N和P的水平是非常低的，相对于其他地方的典型土壤。当这些观测结果扩大到区域水平时，可以计算出，土地利用从种植或森林畜牧业系统向苜蓿系统的5%转移可以每年增加多达2000万吨CO2的土壤碳固存，尽管在进行外推时需要谨慎，因为目前的数据来自黄土高原的一个单一地点。(C)2017作者（S）爱思唯尔公司出版代表牧场管理协会
Loess Plateau covers 640 000 km(2) in the central northern China. Despite a semiarid environment, harsh winters, and hot summers, agriculture has been practiced in this region for > 5 000 yr, and the food production systems are among China's oldest. The environment is fragile because the loessial soils are prone to erosion. Sound scientific information is therefore required to underpin future land use planning in the region. To this end, total soil organic carbon (SOC), N, and P stocks were measured in Huanxian County of the wider Loess Plateau, representing five major land use categories. Sites were sampled three times over 3 yr. In all, almost 2 800 soil analyses were performed. A feature of these soils is low SOC content in the A horizon but comparatively small decline with soil depth. For example, SOC levels for the 0-20 cm and 70-100 cm soil depths averaged 6.1 and 4.1 Mg ha(-1), respectively. Alfalfa and rangeland sites had 5.1 Mg ha(-1) (10%) more total than cropland and 7.5 t ha(-1) (16%) more total SOC to 100-cm soil depth than the two silvopastoral sites. For total soil N (0- to 100-cm soil depth) the averages of alfalfa and RL sites were 20% and 28%, respectively, higher than the cropland and silvopastoral site group means, although soil C, N, and P levels are very low, relative to those of typical soils elsewhere. When these observations are scaled up to a regional level, it can be calculated that a 5% shift in land use from cropping or silvopastoral systems to alfalfa-based systems could increase soil C sequestration by as many as 20 million t CO2 per yr, although some caution is needed in making extrapolations, as the present data are from a single locality on the Loess Plateau. (C) 2017 The Author(s). Published by Elsevier Inc. on behalf of The Society for Range Management.