Effects of straw mixed mulch length and coverage on infiltration, soil and water loss of Loess Plateau slopes

To study the influence of the wheat straw length and mulching on soil erosion under mixed mulch application, indoor simulation experiments were adopted to study the characteristics of infiltration, runoff and sediment yield changes under a rainfall intensity of 90 mm hr(-1). The results indicated that the length, coverage and interaction imposed significant effects on these variables. With increasing coverage, the infiltration exhibits a trend of first increasing and then decreasing. The change trend of runoff and sediment is the opposite of the infiltration trend. When the length is less than or equal to 8-10 cm and the coverage is lower than 4.5 t hm(-2), the sum of the length and coverage multiplied by the length and coverage attains a power function relationship with the slope infiltration rate. When the length is greater than or equal to 8-10 cm and the coverage is lower than 4.5 t hm(-2), the sum of the length and coverage multiplied by the coverage divided by the length attains a power function relationship with slope infiltration rate. The reciprocal of these two variables attains a power function relationship with runoff and sediment yield. In this study, when the length ranged from 8-10 cm and the coverage was 3.5 t hm(-2), the average infiltration rate was the highest, and the cumulative runoff and sediment yield were the lowest. Mixed straw mulching can effectively increase infiltration and reduce runoff and sediment yield, which is of great significance for the sustainable development of agriculture and ecology on slope farms.