Alleycropping

Alleycropping involves growing crops (grains, forages, vegetables, etc.) between trees planted in rows. The spacing between the rows is designed to accommodate the mature size of the trees while leaving room for the planned alley crops. When sun-loving plants like corn or some herbs will be alleycropped, the alleyways need to be wide enough to let in plenty of light even when the trees have matured.

Silvopasture

Tree and pasture combinations are called silvopastoral agroforestry. Hardwoods (sometimes nut trees) and/or pines are planted in single or multiple rows, and livestock graze between them. Although both the trees and the livestock must be managed for production, some systems emphasize one over the other. Usually, in the early years of establishment, crops or hay are harvested from the planting. Grazing generally begins after two or three years, when the trees are large enough that the livestock can't damage them. In other instances, tree tubes and electric fencing protect the young trees, and grazing begins immediately.

Windbreaks and Shelterbelts

Extensive research on windbreaks, also called shelterbelts, has been carried out in the U.S. Trees are planted in single or multiple rows along the edge of a field to reduce wind effects on crops or livestock. Windbreaks have been shown to reduce wind impact over a horizontal distance equalling at least ten times the height of the trees. Wind and water erosion are reduced, creating a moist, more favorable microclimate for the crop. In the winter the windbreak traps snow, and any winter crops or livestock are protected from chilling winds. Beneficial insects find permanent habitat in windbreaks, enhancing crop protection.

Riparian Buffer Strips

Trees, grasses, and/or shrubs planted in areas along streams or rivers are called riparian buffers or filter strips. These plantings are designed to catch soil, excess nutrients, and chemical pesticides moving over the land's surface before they enter waterways. Such plantings also physically stabilize streambanks. On cropland that is tiled to improve drainage, polluted water can flow directly into streams; constructed wetlands installed in the buffers can capture and clean this drainage water before it enters the stream.

Forest Farming (special forest products).

            When a natural forested area is managed for both wood products and an additional enterprise, it becomes an agroforestry system. For help with the management of timber, county Extension agents can refer farmers to Extension forestry specialists. These specialists are qualified to give advice on thinning, pruning, and harvesting practices, as well as on marketing options. They may or may not be able to visit the farm for on-site consultation. The Association of Consulting Foresters of America (See Further Resources below) can refer you to private forestry consultants in your area.

http://attra.ncat.org/attra-pub/agroforestry.html for more information about Agroforestry.