青藏高原南部不同土地利用方式土壤可蚀性分析  

Analyze on soil erodibility of different land uses in southern Qinghai-Tibet Plateau

作　　者：李笑雨 白金珂 王力[1,2] LI Xiaoyu;BAI Jinke;WANG Li(College of Natural Resources and Environment,Northwest A&F University,712100,Yangling,Shaanxi,China;State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau,Institute of Soil and Water Conservation,Chinese Academy of Sciences and Ministry of Water Resources,712100,Yangling,Shaanxi,China)

机构地区：[1]西北农林科技大学资源环境学院,陕西杨凌712100 [2]中国科学院水利部水土保持研究所土壤侵蚀与旱地农业国家重点实验室,陕西杨凌712100

出　　处：《中国水土保持科学》2024年第4期68-74,共7页Science of Soil and Water Conservation

基　　金：国家计委、科技部科研项目“第二次青藏高原综合科学考察研究”(2019QZKK0306)。

摘　　要：为评估青藏高原南部不同土地利用类型土壤侵蚀风险,对该地区4种典型土地利用类型土壤进行大范围采样,测定土壤颗粒组成和有机碳质量分数,计算土壤分形维数和可蚀性因子K,对不同土地利用类型和不同土层土壤侵蚀风险进行定量化评估,并分析土壤粒度特征对土壤可蚀性因子的影响。结果表明:1)整体来看,研究区土壤可蚀性因子K介于0.022~0.036 t·hm^(2)·h/(hm^(2)·MJ·mm)之间,超过40%的样地土壤属于中可蚀性以上(K>0.033 t·hm^(2)·h/(hm^(2)·MJ·mm))土壤,存在较高的侵蚀风险;2)在不同土地利用方式间,土壤可蚀性因子表现为耕地>灌木林地>草地>乔木林地,其中耕地土壤可蚀性因子显著高于其他3种土地利用类型(P<0.05);3)垂直剖面上,由上到下3个土层(0~10、10~20和20~30 cm),中可蚀性以上土壤分别占到样点总数的26.47%、47.22%和55.89%,中低可蚀性以下(K≤0.033 t·hm^(2)·h/(hm^(2)·MJ·mm))土壤分别占73.53%、52.78%和44.11%,土壤可蚀性因子随土壤深度增加呈递增趋势;4)土壤粒度特征对可蚀性具有重要影响,土壤可蚀性因子K与砂粒含量呈指数型负相关关系,与黏粒含量和分形维数呈指数型正相关关系,均达到极显著水平(P<0.001)。研究结果可为降低青藏高原南部地区土壤侵蚀风险及提高水土保持效益提供重要参考。[Background]Erosion is one of the main causes of soil degradation worldwide.The Qinghai-Tibet Plateau is a vast area with obvious differences in topography,climate,and vegetation in different areas,covering almost all terrestrial soil erosion types.This brings a huge risk of erosion to the soil,which will seriously threaten its ecological barrier function.Quantitative assessment of soil erosion risk in the southern Qinghai-Tibet Plateau,so as to fully understand the status quo of soil erodibility in the study area,and put forward reasonable suggestions,which will help reduce the risk of soil erosion in the study area.[Methods]In this study,a large-scale sampling was carried out in the southern Qinghai-Tibet Plateau,and four typical land use patterns(Farmland,grassland,woodland,and shrubland)in this area were taken as the research objects.The composition of soil particles and organic carbon mass fraction were measured,and the soil fractal dimension was calculated.Quantitatively assess the soil erosion risks of different land use types and different soil layers,and analyze the impact of soil particle size characteristics on soil erodibility.[Results]The K value of soil erosion in the study area ranged from 0.022-0.036 t·hm^(2)·h/(hm^(2)·MJ·mm),the proportion of soil above medium erosion(K>0.033 t·hm^(2)·h/(hm^(2)·MJ·mm))was 43.19%,and the risk of soil erosion in the southern Qinghai-Tibet Plateau was higher.There were general differences in soil erosion among different land use types,soil erodibility was as follows:farmland>shrubland>grassland>woodland,and the soil erosion of farmland was significantly higher than that of the other three land use types(P<0.05).In the soil vertical profile,the proportions of sample points with above-medium erosion(K>0.033 t·hm^(2)·h/(hm^(2)·MJ·mm))for the three soil layers(0-10,10-20,and 20-30 cm)were 26.47%,47.22%and 55.89%,respectively.Conversely,the proportions of sample points with below-medium and low erosion(K≤0.033 t·hm^(2)·h/(hm^(2)·MJ·mm))were 73.53%,52.78

关 键 词：大尺度 土壤可蚀性因子K 土壤颗粒特征 土壤有机碳 分形维数 青藏高原 

分 类 号：S152.7[农业科学—土壤学]