黄土丘陵沟壑区不同草灌植被土壤分离速率及其主导因素  

Soil Separation Rates and Its Dominant Factors of Different Herbaceous and Shrub Vegetation in Loess Hilly and Gully Region

作　　者：尚永泽 马波 李占斌[1,2] 马建业 王晨光[1] Shang Yongze;Ma Bo;Li Zhanbin;Ma Jianye;Wang Chenguang(State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau,Institute of Soil and Water Conservation,Northwest A&F University,Yangling,Shaanxi 712100,China;Institute of Soil and Water Conservation,CAS&MWR,Yangling,Shannxi 712100,China)

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

出　　处：《水土保持通报》2022年第2期46-52,共7页Bulletin of Soil and Water Conservation

基　　金：国家自然科学基金项目“黄土高原冻融对水蚀过程的作用机理研究”(41771311);国家自然科学基金国际(地区)合作与交流项目“尼罗河上游丘陵区水土保持与高产高效农业研究”(41561144011)。

摘　　要：[目的]探究不同草灌植被条件下土壤理化性质和根系特征对土壤分离速率的影响强度,为黄土高原生态建设成效的评估提供科学依据。[方法]分别选取黄土高原典型直根系灌木柠条锦鸡儿(Caragana korshinskii)、须根系草本冰草(Agropyron cristatum)和直根系草本植物铁杆蒿(Artemisia gmelinii)及其复合群落为研究对象,采集原状土样,在坡度为15°,流量为36 L/min的条件下,进行土壤分离试验,估算其分离速率,并测定相关土壤参数和根系参数。[结果]草灌复合使分离速率较单一草本和灌木的均值降低了73.58%,其中锦鸡儿与冰草的复合模式减蚀效果最强。影响土壤分离速率的最主要根系因子为根长密度和根重密度,主要土壤因子为>0.25 mm的团聚体含量。根系因子是影响草本植物土壤分离速率最主要的因子。灌木及草灌复合下的土壤分离速率受到土壤因子和根系因子的共同主导。[结论]草灌复合根系能够有效提高土壤抗分离能力,其中以直根系与须根系的根系构型组合效果最强,且不同的根系构型组合在影响土壤性质的程度和发挥抗分离作用时的主导因子不同。[Objective]The influence of soil physical and chemical properties and root characteristics on soil detachment rate under different mixed herbs and shrubs was explored in order to provide scientific basis for the evaluation of ecological construction effect in the Loess Plateau.[Methods]Typical taproot shrub Caragana korshinskii,fibrous root herb Artemisia gmelinii and taproot herb Agropyron cristatum,and their composite community were selected as research objects,and the undisturbed soil samples were collected.Soil separation experiment was carried out at a slope of 15°with a flow rate of 36 L/min,the separation rate was estimate,and the related root and soil parameters were determined.[Results]The detachment rate of grass shrub combination was 73.58%lower than that of the single herb and shrub,and the erosion reduction effect of Caragana korshinskii and Agropyron cristatum was the strongest.Correlation showed that the main root factors influencing soil detachment rate were root length density and root weight density,the main factor of soil was aggregate content>0.25 mm,the root factor was one of the main factors affecting soil separation rate of herbaceous plants.And the soil separation rate under the combination of shrub and grass was dominated by both soil factor and root factor.[Conclusion]Herb-shrub combined root system can effectively improve soil anti-scour ability,among which the combination of root architecture of taproot system and fibrous root system has the strongest effect,and different root architecture combinations have different leading factors affecting soil properties and anti-scour.

关 键 词：草灌复合 土壤分离率 根系特征 土壤理化性质 根系构型 

分 类 号：S152.49[农业科学—土壤学] S157.1[农业科学—农业基础科学]