Mulching practices for reducing soil water erosion: A review

Among the soil conservation practices that are used, mulching has been successfully applied to reduce soil and water losses in different contexts, such as agricultural lands, fire-affected areas, rangelands and anthropic sites. In these contexts, soil erosion by water is a serious problem, especially in semi-arid and semi-humid areas of the world. Although the beneficial effects of mulching are known, further research is needed to quantify them, especially in areas where soil erosion by water represents a severe threat. In the literature, there are still some uncertainties about how to maximize the effectiveness of mulching to reduce the soil and water loss rates. Given the seriousness of soil erosion by water and the uncertainties that are still associated with the correct use of mulching, this study review aims to (i) develop a documented and global database on the use of mulching with vegetative residues; (ii) quantify the effects of mulching on soil and water losses based on different measurement methods and, consequently, different spatial scales; (iii) evaluate the effects of different types of mulches on soil and water losses based on different measurement methods; and (iv) provide suggestions for more sustainable soil management. The data published in the literature have been collected. The results showed the beneficial effects of mulching in combating soil erosion by water in all of the environments considered here, with reduction rates in the average sediment concentration, soil loss and runoff volume that, in some cases, exceeded 90%. However, the economic feasibility of mulching application was not readily available in the literature. Therefore, more research should be performed to help both farmers and land managers by providing them with evidence-based means for implementing more sustainable soil management practices.