August 5, 2020
Definition: A naturally occurring process that removes and displaces organic material like rock or soil from a landscape. In agriculture, soil erosion refers to the wearing away of a field's topsoil by the natural physical forces of water and wind or through forces associated with farming activities such as tillage.
Mitigating Erosion in the Forest Garden: Unsustainable farming practices can contribute to soil erosion, while sustainable practices like agroforestry can help restore soil and limit erosion. The topsoil in a Forest Garden is a critical component in maximizing and optimizing the productivity of a parcel of land. The more stable and fertile the topsoil, the healthier and more vigorous the growth of the Forest Garden. As a result, Forest Garden farmers adopt the following techniques to prevent that topsoil from being eroded away by either wind or rain.
Combating Wind Damage: To mitigate the damage from strong winds, farmers plant what is known as a windbreak along the side of the field that faces the strongest winds. A windbreak can consist simply of one row of trees, but the most effective windbreaks have multiple, staggered rows with shorter shrubs and trees comprising the outer row and taller trees making up the second row. This will guide the wind up and over the field rather than through it. A windbreak can protect land up to 10 times the height of its tallest trees.
Combating Water Damage: To mitigate damage from water, farmers practice contour planting as well as alley cropping. Using contour planting, farmers are able to create vegetative barriers along sloped land that prevent rain from running off the hillside while carrying away topsoil and its nutrients. By planting alleys of nitrogen fixing species across a parcel of land, farmers are able to replenish and stabilize the soil in preparation for rains to come. Learn more about erosion in Chapter 8 of the Technical Manual.