晋西黄土区不同土地利用方式对土壤抗冲性及糙率的影响

Effect of Different Land Use Types on Soil Anti-scourability and Roughness in Loess Area of Western Shanxi Province

采用野外实地放水冲刷法,以次生林地、刺槐林地、荒草地、农地为研究对象,研究晋西黄土区蔡家川流域不同土地利用方式对土壤抗冲性及糙率的影响及其与可能的影响因子之间的关系。结果表明:(1)各样地土壤有机质含量大小为次生林地>农地>刺槐林地>荒草地。有机质含量与土壤抗冲性呈极显著负相关(p<0.01)。(2)试验地的糙率系数介于0.005 6～0.251之间,糙率系数n值大小顺序为次生林地>刺槐林地>农地>荒草地;(3)土壤抗冲性受土地利用方式、植物根系以及坡度等因素的影响较大。土壤抗冲性随根系生物量的增加而增强,且与<1mm的根系密度极显著相关(p<0.01);不同土地利用方式下土壤抗冲性大小表现为:次生林地土壤抗冲性能最强,刺槐林地和荒草地次之,农地最差。

Using the method of scouring experiment in field,this research took secondary forest land,Robinia pseudoacaciaforest land,wasteland and farmland as the study objection to study the influence and relationship of different land use on soil anti-scourability and roughness coefficient in loess area of western Shanxi province,Caijiachuan watershed.The results showed as following:(1)The order of soil organic matter content in four kinds of lands was secondary forest land>farmland>Robinia pseudoacacia forest land>wasteland.There was significant negative correlation between soil organic matter content and soil anti-scourability(p<0.01).(2)The roughness coefficient of experimental field ranged from 0.005 6to 0.251,and the order of roughness coefficient in different land use type was secondary forest land>Robinia pseudoacaciaforest land>farmland >wasteland.(3)Soil anti-scourability was significantly impacted by land use types,plant roots,gradient etc.,soil anti-scourability strengthened with increasing roots biomass and it had highly significant correlation with the roots density which less than 1millimeter(p<0.01).Soil anti-scouriability in different land use types as secondary forest land was the strongest type,followed by Robinia pseudoacacia forest land and wasteland,the farmland was the worst one among four land use types.