|WANG, JIAN - Northwest Agriculture And Forestry University|
|MENG, QINQIAN - Northwest Agriculture And Forestry University|
|ZHANG, QINGFENG - Northwest Agriculture And Forestry University|
|Way, Thomas - Tom|
Submitted to: Soil Science Society of America Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/3/2016
Publication Date: 7/5/2016
Citation: Wang, J., Watts, D.B., Meng, Q., Zhang, Q., Way, T.R. 2016. Influence of surface crusting on infiltration of a loess plateau soil. Soil Science Society of America Journal. 80:683-692.
Interpretive Summary: Soil crusts often form on the surface of cultivated farmland. These crusts often seal the soil surface preventing rainwater from moving into the ground. These crusts can negatively influence crop production and may promote surface water runoff. Thus, a simulated rainfall study was conducted to evaluate the influence of soil crusting in the Loess Plateau of China on slopping land and results compared with an infiltration model to predict the amount of water entering the soil. Infiltration was decreased under soil crusts and the time between when the rainfall event began and the occurrence of runoff also decreased with crusted soil compared to soil without crusts. Use of the Green Ampt predictive model provided a good estimation of the influence of soil crusting.
Technical Abstract: Surface sealing and crusting are common widespread processes that occur in many cultivated soils worldwide, especially in arid and semiarid regions. Soil crusting negatively affects water infiltration, increases surface runoff, reduces seedling emergence, restricts air exchange between the soil and atmosphere, and negatively impacts crop production. Crust formation is a frequent occurrence on farmland soil of the Loess Plateau region in China and often adversely affects agricultural yields. Therefore, a study was conducted to evaluate the occurrence of soil crusting and its influence on infiltration in soil of the Loess Plateau (silt loam soil). Simulated rainfall events were conducted at two intensities (0.67 and 1.33 mm min-1) on four slopes (5.24, 8.74, 17.62, and 28.78%) under two soil conditions (crusted and non-crusted). Infiltration was evaluated as the difference between precipitation applied and water lost to runoff. Infiltration data was compared using a modified Green-Ampt model for describing infiltration of crusted soil. The mean thickness of soil crust formation was 3.33 mm and 3.94 mm under rainfall intensities 0.67mm min-1 and 1.33mm min-1, respectively. However, slope had no effect on crust formation. Soil surface conditions greatly influenced infiltration and runoff. In all instances, cumulative infiltration was lower in soil with crusts compared to soil without. Time to create runoff decreased from 17.98 min in soil without crusts to 4.64 min in soil with crusts formed under a rainfall intensity of 0.67 mm min-1. Time to runoff also decreased from 16.25 min in soil without crusts to 4.54 min in soil with crusts formed at a rainfall intensity of 1.33 mm min-1. The Green Ampt model provided a good estimate of soil crusting’s influence on infiltration. This suggests that the Green-Ampt model could be used as a tool for predicting soil crusting’s influence on infiltration and runoff from soils in the Loess Plateau region.