Mulch is used for various purposes:

• to retain water by slowing evaporation
• to adjust temperature by helping soil retain more heat in winter, and by keeping soil cool and even out temperature swings during hot  summer conditions
• to control weeds by blocking the sunlight
• to add organic matter and nutrients to the soil through the gradual breakdown of the mulch material
• for erosion control - protects soil from rain and preserves moisture

Materials

• Dry Mulch - uprooted weeds, grass clippings, leaves, hay, straw, shredded bark,  sawdust, shells, wood chips, shredded newspaper, etc. Many of these materials also act as a direct composting system.
• Live Mulch - Fast-growing ground cover crop (eg. velvet beans) that will provide weed suppression and also aid in nitrogen fixing.

We have mainly adopted dry mulching by using straw/grass/weeds cleared around the farm. The mulching height is between 2-4 inches. They have been very effective in retaining the moisture for considerable number of days. We have used the mulch mainly for all the fruiting trees which get watered once in 7-10 days. Even on the 7th day, have noticed sufficient moisture in the top soil. This has also resulted in less usage of water. However, where weeds (mainly parthaneum) were used, occasionally ended up having weed growth at the mulch area.