Role of woodchips on runoff components control at plot scale

In severely eroded areas, especially steep slopes, establishment of vegetation cover is not possible. The application of organic and inorganic amendments can therefore improve the conditions leading to establish vegetation cover through playing an effective role in runoff control. Accordingly, in the present study, woodchips as a soil organic amendment was applied to control runoff variables including time to runoff, runoff volume and coefficient. For this purpose, three levels of woodchips treatment of 0.5, 1.0 and 1.5 kgm-2 were used in three replications at in 1 m2- plot scale. The plots were located in 30% slope in accordance with field conditions under simulated rainfall of 60 mmh-1 and duration of 15 min. The results showed that application of woodchips in 0.5, 1.0 and 1.5 kgm-2, time to runoff increased 97.50, 192.38 and 203.31%, respectively. The runoff volume decreased 35.23, 55.11 and 60.43% and runoff coefficient also decreased 42.43, 67.40 and 72.14% in three levels of woodchips treatments, respectively. The results of GLM showed that woodchips treatment had a significant increasing effect on time to runoff (p≤0.01) as well as a significant decreasing effect on runoff volume and coefficient (p≤0.05). The application of woodchips as a conservation treatment on the soil surface showed that this amendment can be used for runoff control especially where large quantities of woodchips are simply available.