Bunding in Agriculture
One method of erosion control requiring mechanical measures using engineering techniques is bunding. Bunding reduces run off and helps impound water longer for it to infiltrate the soil.
In this case, we use two types of bunding namely block and contour bunding.
Block bunding is done via construction of big bunds (usually of earth or stone or both) across large blocks of sloping lands to enclose water and seize soil washed from the fields lying above. The bunding is made to withstand the force of water from the catchment. Water is let out at the end of the rainy season and land, which has received fertile silt, is planted with crops.
Contour-bunding consists in making a narrow-based embankment at intervals across the slope of the land on a level that is along the contour. This method conserves soil and water in arid and semi-arid areas with high infiltration and permeability, and is commonly adopted on agricultural land up to a slope of about 6%.