Mulching is the process of covering the topsoil with plant material such as leaves, grass, twigs, crop residues, straw etc. A mulch cover enhances the activity of soil organisms such as earthworms. They help to create a soil structure with plenty of smaller and larger pores through which rainwater can easily infiltrate into the soil, thus reducing surface runoff. As the mulch material decomposes, it increases the content of organic matter in the soil. Soil organic matter helps create good soil with stable crumb structure. Thus, the soil particles will not be easily carried away by water. Therefore, mulching plays a crucial role in preventing soil erosion. The following describes the technique of mulching in organic agriculture. Details on the benefits and why use mulch are given. The selection and source of mulching materials are also provided as well as recommendations while using mulch and its application. A case study of the Fukuoka system of mulching rice fields highlights the benefits of this technology.