Cover crops have many potential benefits, Ingels observes. One of their most important uses is to reduce soil erosion. Also, legume cover crops add nitrogen to the soil, thus reducing the need for synthetic fertilizers. Cover crops can also prevent leaching of soil nitrate to groundwater, improve soil tilth and water penetration, suppress weeds and harmful nematodes and provide habitat for beneficial insects and spiders. Some cover crops are aesthetically pleasing, an important attribute for coastal and foothill wineries.
Cover crops can have some drawbacks, however.
They increase water demand and compete with vines for soil moisture and nutrients, although these characteristics can be used to reduce excessive vine vigor. They may also exacerbate some pest problems, such as flower thrips, gophers and meadow voles. Cover crops also add additional costs associated with planting, tending and management, but many growers find that the benefits outweigh the costs. Discounts are available on orders of 10 or more copies. Shipping and sales tax charges are added to the purchase price.