Natural mulches include straw, wood chips, leaves, cured manure, compost, peat moss, sawdust, grass clippings, and ground corncobs. Synthetic mulches include aluminum foil, newspaper, cardboard, porous fabrics and clear or black plastics. Natural mulches will decompose and can be turned under in the fall to improve soil tilth. Natural mulches encourage soil biological activity. Soil moisture is conserved and root zone temperatures are reduced.
Natural mulches can be bulky and difficult to apply for large scale farmers.
Different synthetic mulches accomplish different goals. Aluminum foil reflects sunlight and keeps soil cool. Clear and black plastic work by absorbing heat. Plastic mulches are often used in large scale commercial farming. Vegetables can be planted earlier in the season or maturation time decreased using these materials.