黄土丘陵区须根系作物地土壤分离季节变化研究

采用变坡试验水槽的试验方法,研究了黄土丘陵区典型须根系作物玉米和谷子在生长季土壤分离能力的季节变化及潜在影响因素。结果表明:在作物生长季,须根系作物玉米地和谷子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;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;两种作物地的土壤分离能力可以用土壤粘结力、作物根系密度和水流剪切力很好地拟合(R~20.75,NSE0.74)。

Seasonal Changes of Soil Detachment Capacity Under Two Typical Fibrous Crops in Hilly Region of Loess Plateau of China

In order to provide scientific basis for soil and water conservation measurements of the loess plateau, overland flow with a hydraulic flume with adjustable bed gradients was used to study the seasonal changes in soil detachment capacity and the potential influential factors during one growing season of maize and millet in 2012. The results showed that the soil detachment capacity for each fibrous crop fluctuated significantly over time with a similar pattern of seasonal change. The seasonal changes of soil detachment capacity were affected by tillage practices, soil consolidation, water-stable aggregates, and root growth. Soil detachment capacities of two fibrous crops could be estimated by using flow shear stress, soil cohesion and root density (R2>0.75,NSE>0.74).