Cover crops as a means of ecological weed management in agroecosystems

Abstract

Weeds cause an estimated crop yield loss of about 43% world-wide. The heavy use of herbicides in weed management has several environmental and health risks. Therefore, systems-oriented approaches to weed management that make better use of alternative weed management tactics need to be developed. One of these approaches is the use of plants with strong weed-suppressing abilities as a component of integrated crop management. Cover crops are well-suited in such a holistic approach as they provide many other agroecosystem services besides suppressing weeds. However, compared to the use of herbicides, the use of cover crops as a weed management tool needs careful follow-up throughout the intended period to maximize the agroecosystem services they provide, minimize the disservices they exert, and optimize their selectivity between weed and crop suppression. Although there are many review papers that address the contribution of cover crops for managing weed problems in agroecosystems, few systematically address the difficulties that are encountered in fitting in the cover crops in the different cropping systems and the methods how to overcome these difficulties. Therefore, this paper is to examine how to maximize weed suppressive effects of cover crops and minimize the negative side effects of introducing cover crops into annual and perennial cropping systems and how to optimize selectivity between weeds and crops. We suggest further research regarding the selection of cover crops that are compatible with annual and perennial cropping systems under different climatic conditions and identify the traits responsible for adaptation in various cropping systems and environments.