摘要
团聚体稳定性是表征土壤结构稳定性的重要指标,与坡面水文过程及侵蚀过程密切相关,为探明黄土高原团聚体稳定性(aggregatestability,MWD)沿降水梯度的变化特征及其影响因素。该论文在黄土高原沿降水梯度布设了7个采样点,测定每个采样点农地、草地和林地的MWD。结果表明,农地MWD沿降水梯度自南向北呈逐渐减小趋势;草地和林地MWD变化趋势比较相似且无显著差异(P=0.233),最南端宜君的MWD小于稍北富县的MWD,之后向北大体呈减小趋势。农地、草地和林地MWD空间变化特征除受土壤有机质、年均降水量和年均气温的影响以外,农地的MWD与土壤机械组成存在显著相关关系(P<0.05),而草地和林地的MWD与根系质量密度存在显著相关关系(P=0.037)。非线性回归表明,农地MWD可以用土壤中值粒径和年均降水量模拟,而草地和林地MWD可用土壤有机质、根系质量密度和年均温模拟。研究成果对于理解黄土高原土壤团聚体稳定性空间变异及其影响因素、分析水文及侵蚀过程的区域变化规律具有理论意义。
Aggregate stability(MWD)is an important indicator of soil structure stability,and closely correlated to the processes of slope hydrology and soil erosion.Up to date,few studies are conducted to investigate the variation of MWD and influencing factors on the regional scale.In order to study the variation characteristics of MWD and influencing factors in the Loess Plateau,a 508 km long transect including seven sampling sites along the precipitation gradient was laid out in this study.The MWD of cropland,grassland and woodland on each sampling site were measured,in the meantime soil mechanical composition,bulk density,soil organic matter,root mass density and vegetation coverage of each sampling site were also measured.The results indicated that there existed significant(P<0.05)difference between the MWD of cropland and the MWD of grassland and woodland.Cropland had the largest mean MWD,followed by woodland;the cropland had the lowest mean MWD.The ratios of the mean MWD of grassland and woodland to the mean MWD of cropland were 2.94 and 2.39,respectively.The reason why the mean MWD of cropland was lowest could be explained by the fact that the lower soil organic matter and root mass density of cropland,and the disturbance of MWD induced by the frequent tillage operations.The MWD of cropland showed a decreasing trend from south to north along the precipitation gradient.The changing trends of the MWD of grassland and woodland were similar,which could be attributed to the similarity of the near surface characteristics(such as non-disturbance,high plant residue return)of grassland and woodland.The MWD of the Yijun was slightly lower than the MWD of Fuxian,and then the MWD of sampling sites showed a generally decreasing trend from Fuxian to Erdos.The MWD of cropland,and grassland and woodland were all influenced by soil organic matter,annual average precipitation and annual average temperature.In addition,there existed a significant(P<0.05)relationship between the MWD of cropland and soil mechanical composition,however t
作者
耿韧
张光辉
洪大林
李振炜
Geng Ren;Zhang Guanghui;Hong Dalin;Li Zhenwei(Sate Key Laboratory of Hydrology-water Resources and Hydraulic Engineering,Nanjing Hydraulic Research Institute,Nanjing 210029,China;School of Geography,Beijing Normal University,Beijing 100875,China;Institute of Subtropical Agriculture,Chinese Academy of Sciences,Changsha 410125,China)
出处
《农业工程学报》
EI
CAS
CSCD
北大核心
2019年第3期141-148,共8页
Transactions of the Chinese Society of Agricultural Engineering
基金
南京水利科学研究院中央级公益性科研院所基本科研业务费专项资金项目(Y918005)
"十三五"国家重大研发计划"黄土丘陵沟壑区坡体-植被系统稳定性及生态灾害阻控技术"(2017YFC0504702)
国家自然科学基金重点项目"退耕驱动近地表特性变化对侵蚀过程的影响及其动力机制"(41530858)
关键词
土壤
土地利用
侵蚀
黄土高原
团聚体稳定性
降水梯度
soils
land use
erosion
Loess Plateau
aggregate stability
precipitation gradient
