AgroForestry

Agroforestry combines agriculture and forestry to create integrated and sustainable land-use systems.  Normally we think of agriculture and woodlands as separate.  But trees and shrubs can be incorporated into the farm in ways that complement your crops and provide additional income and/or environmental and aesthetic benefits.

There are five common categories of agroforestry:

  • windbreaks
  • alley cropping – widely spaced rows of trees with crops planted between them in the early years until the trees cast too much shade
  • silvopasture – timber production in pastures
  • forest farming – production of mushrooms, decorative ferns, medicinal herbs, and/or other woodland plants, and
  • riparian forest buffers – trees and shrubs planted along rivers and streams.

In addition, don’t forget that regular woodland management can also bring in income and benefit wildlife and native plants.

Let’s focus on windbreaks to illustrate some of the potential benefits and challenges of bringing agroforestry to your farm.

Windbreaks are rows of trees and/or shrubs used to reduce and redirect wind.  Field windbreaks can reduce soil erosion and water loss, and farmstead windbreaks can enhance the living environment and reduce home heating costs and dust.  In addition, windbreaks can help shelter livestock and can help keep roads clear of drifting snow.

Although we tend to think of windbreaks as conservation measures, they can be designed to produce marketable products while also delivering environmental services.  For example, evergreen branches and several shrub types could be harvested for making wreaths and other winter floral decorations.   Or you could plant hazelnuts or elderberries or other fruit-producing trees or shrubs as one row of the windbreak.

When you design a windbreak, you need to take a wide variety of factors in mind, beginning with the engineering of the windbreak.  The proper placement of the windbreak will depend on the prevailing winds in that location.  A snow fence located in the wrong place can result in more snow accumulation rather than less!  In addition, the recommended height, width, and density of the windbreak will depend on its purpose.  For winter protection of structures and livestock a windbreak should be at least 60 percent dense, while 40 to 60 percent density is best for crop and soil protection, and 30 percent is adequate for a living snow fence.   The density of the windbreak is determined by what species you plant, how close together they are, and how many rows the windbreak has.   Other factors to consider include your soils, precipitation, and climate, whether you want to attract certain birds or other wildlife, and whether you also want to harvest products from your windbreak.  Since establishment of a windbreak takes a considerable investment of time, labor, and money, it is well worth getting expert assistance with your planning.

Your local Natural Resources Conservation Service office may be able to provide technical assistance for designing a windbreak and may also be able to offer some financial help with the costs of planting.  Professional foresters can help advise on species selection and proper maintenance, though most will be more familiar with traditional forest management than with agroforestry.  You can find a series of easy to read publications on windbreaks at http://www.unl.edu/nac/morepublications.htm .

There are a several places you can go for more information on agroforestry.  The National Agroforestry Center website at http://www.unl.edu/nac/index.htm is a good place to start.  Another website with a lot of good information is the University of Missouri’s Center for Agroforestry at http://www.centerforagroforestry.org/index.htm .

The resources on the University of Minnesota’s agroforestry website at http://www.extension.umn.edu/Agroforestry/ are developed for a climate much like ours in Wisconsin.

Information for this article was taken from Working Trees for Agriculture http://www.unl.edu/nac/brochures/wta/ , Windbreaks in Sustainable Agricultural Systems http://www.nfs.unl.edu/documents/windbreaksustainableag.pdf, and Living Snow Fences http://www.extension.umn.edu/distribution/naturalresources/DD7277.html