黄土区直根系作物地土壤分离生长季动态*

目的为黄土高原土壤侵蚀控制提供科学依据。方法运用变坡试验水槽的实验方法,研究了黄土高原地区典型直根系作物大豆和马铃薯在生长季土壤分离过程的季节变化及潜在影响因素。结果 1在作物生长季,直根系作物大豆地和马铃薯地的土壤分离能力具有明显的季节变化(P0.05),并表现出了相似的季节变化模式;2两种作物地土壤分离能力的季节变化主要受到农事活动、土壤硬化、水稳性团聚体和作物根系生长的影响;3两种作物地土壤分离能力的季节变化可以用水流剪切力、土壤粘结力和作物根系密度很好地模拟(R20.64,NSE0.63)。结论黄土区直根系作物地土壤分离过程具有明显季节变化,该变化主要是由农事活动、土壤粘结力和作物根系密度季节变化影响所致。

The dynamics of soil detachment during the growing season of taproot crops in the Loess Plateau of China

Purposes—To provide scientific basis for soil erosion control of the loess plateau . Methods—The changing slope sink experiment is used to study seasonal variations and potential influ‐ence factors during soil detachment in the growing season of soybean and potato ,typical taproot crops in the Loess Plateau of China .Results— ① Soil detachment capacity for each taproot crop fluctuated significantly over time with a similar pattern of the seasonal variation .② The seasonal variations of soil detachment capacity were affected by tillage practices ,soil consolidation ,water -stable aggre‐gates and crop root growth .③ Soil detachment capacity of the lands of two taproot crops could be es‐timated with flow shear stress ,soil cohesion ,and crop root density (R2 >0 .64 ,NSE>0 .63) .Conclu‐sions—Soil detachment capacity on the lands of two taproot crops significantly displays the seasonal variation ,which were affected by tillage practices ,soil consolidation and root growth .