Published online by Cambridge University Press: 30 October 2009
Little is known of how vertebrate pest and beneficial species respond to cover crops in vineyards and orchards. During spring 19941 interviewed 22 people who work with cover crops in California and searched for vertebrates and their signs in 36 field plots where cover crops were grown. Farmers usually relaxed concern for vertebrate pests after planting cover crops. But cover crops were thought to increase venebrate damage to trees and vines when planted continuously across the rows or grown in orchards and vineyards less than three years old. Vertebrates usually were not abundant or harmful to the commercial crops and cover crops I examined. Gophers were most abundant in older, uneven, scrappy, or weedy cover crops. They preferred beneficial and insectary blends and Cahaba white vetch, and were least abundant in grasses, subclover mixes, and bur medic. Voles preferred nontillage clover mixes, but avoided bare ground under vine and tree rows. All small mammals were more numerous near streams and recently tilled fields. Cover crops attracted many predatory vertebrates, which improve the aesthetic quality of the farm and might keep animal damage to economically acceptable levels. Cover crops can contribute to wildlife conservation in California, especially if the area in cover crops continues to increase.