河套灌区不同土地利用方式下土壤有机碳的差异

Differences in soil total organic carbon under different land-use patterns in the Hetao Irrigation Region

为了分析河套永济灌域土壤有机碳（TOC）的空间分布及对不同土地利用方式的响应,测定了灌区3种主要土地利用方式下0-100 cm土壤剖面TOC的含量,对比分析不同土地利用方式下土壤TOC含量的差异性。结果表明：土壤TOC含量在0.17%-1.28%,平均为0.66%,在0-100 cm剖面上差异显著,且随土壤深度增加含量降低;在水平方向上,TOC分布差异性较小,总体呈现由南向北微弱递增的趋势;土壤TOC含量的变化因不同土地利用类型的不同而存在差异,含量大小顺序为林地〉农田〉荒地;施肥对土壤TOC含量的影响主要发生在0-40及60-80 cm土层中,且施肥土壤TOC含量在垂直剖面含量变化显著。本研究中,灌区土壤TOC含量在垂直分布上差异较为明显,且对不同土地利用方式的相应不同,其中以施肥土壤TOC含量最高。

In order to investigate the spatial distribution and the responses to different land-use patterns of soil total organic carbon （TOC） in the Yongji of the Hetao Irrigation Region, the TOC concentrations at depths of 0-100 em under three land-use patterns were measured. The results showed that TOC concentrations were in the range of 0.17%- 1.28% with an average of 0.66%, which decreased significantly with soil depth. In horizontal direction, there were no significant differences in TOC distribution, and TOC concentrations increased slightly from south to north. There were significant differences of TOC concentrations in different land-use patterns, decrea- sing in the order of forestland 〉 cropland 〉 wasteland. The effects of fertilization on TOC occurred primarily at 0-40 cm and 60-80 cm soil depth, and significant differences in TOC concentrations occurred in vertical profiles of fertilized soil. In conclusion, TOC concentrations differed signifi- cantly in vertical soil distribution and different land-use patterns, and TOC concentrations were higher in fertilized than unfertilized soil in our study.