Use of contour buffer strips in commodity crop systems in southwestern Wisconsin helps reduce soil loss and traps nutrients on slopes. Photo courtesy of Wisconsin Farm Bureau Federation.
Conservation lands in Wisconsin are publically and privately owned. Most privately-owned conservation lands are unsuitable for agriculture. So-called marginal lands are those that have one or more characteristics not conducive to annual crop production, such as steep slopes, shallow soils, or areas prone to drought or flood. Some marginal lands are remnants of native plant communities and are areas where native animal populations persist. Row-cop production on some marginal lands is associated with high soil erosion rates and decreased productivity over time.
Marginal lands can be used as pasture or for haying, but in times of high row crop prices, marginal lands are sometimes converted to row crops. In the U.S., various public policies and federal programs such as the Conservation Reserve Program (CRP) have been created to slow or reverse such trends. In addition to agricultural uses, marginal lands as a broad category of land type provide a variety of environmental benefits. The exact type and extent of these benefits are influenced by the location of marginal lands and their use and management. Policies and programs like CRP aim to protect the environmental benefits that marginal lands provide.
Marginal lands are being considered for production of biomass? for bioenergy?, not only for meeting mandated renewable fuel mandates, but also as a potential means for avoiding land use conflicts contributing to a “food v. fuel” debate. Conversion of steep or wet land currently in food crop production (i.e., row crop) to less intensive bioenergy crops such as high-diversity low-input perennial mixes has the potential to generate yields and also environmental benefits not readily attained in row crop production. However, some researchers caution that conversion of marginal lands to intensively managed bioenergy cropping systems could lead to permanent land degradation and net increase in GHGs?. Government, academic and private sector research is needed to assess whether and to what degree marginal lands can and should be relied upon for meeting future bioenergy demand.