How Agroforestry Works

The green movement is becoming more and more popular, gaining momentum daily. And there are many popular systems and programs that can help restore some of Earth's depleted resources. Agroforestry is one practice that does just that. From its name, you're probably able to see it has something to do with combining agriculture and forestry.

A more formal explanation is that it is an ecologically based natural resources management system that was devised to promote sustainability within economic, environmental and social sectors. Essentially, it is the practice of growing trees in areas that are already, or have the potential to be, agriculturally productive [source: World Agroforestry Centre]. Through intercropping - growing two or more crops in the same field (in this case both woody and non-woody plants), farmers and other landowners are able to diversify their earning potential by increasing the yield of their lands. Agroforestry can be implemented on farmland, rangeland and other land areas.

Although it is practiced worldwide in both tropical and temperate regions, agroforestry has been most extensively practiced in developing nations. It's been on the table in the U.S. for a while but didn't catch on until the late 1960s and early 1970s as its role in food production and soil conservation became of interest. The U.S. still remembered the hardships associated with the great depression and four major factors brought agroforestry into the eyes of the nation.

First, citizens were starting to consider what negative impacts they were having on the environment. Agroforestry could help replenish our nation's natural resources as well as help fuel the slow economy. Second, fossil fuel was becoming harder and harder to come by, causing prices to increase. Third, food production capacities were being affected by increased soil erosion, which trees plantings can help prevent. Finally, the world population was continuously growing and demanding more output [source: Rietveld].

There's a lot of positive information available on agroforestry. Among its proven environmental and economic impacts are the following:

A reduction in poverty levels due to increased production of agroforestry products
An increase in soil fertility
Accessible fuel wood for farmers, protecting other areas from deforestation or depleted woodlands
More diversity in farm tree crops
Provides some protection against the climate changes seen worldwide
Accessible medicinal trees, which provide medication around the globe [source: World Agroforestry Centre]

Read on to discover just how agroforestry works.

Agroforestry Principles

So we know what agroforestry is, but let's get some more specific details.

The idea behind agroforestry is to create an opportunity that's as beneficial as possible. It goes beyond aesthetic value. When landowners undertake agroforestry, they get the specific benefits that trees provide. But beyond that, it's a good step toward replenishing the world of diminishing resources that human consumption and expansion have caused. By practicing agroforestry, we not only get the immediate benefits but we can continue to study the practice and develop new methods.

Here are some of the most common agroforestry practices:

Alley cropping - planting trees between rows of already grown shrubs or trees
Riparian forest buffers - planting trees next to bodies of water
Silvopasture - sustainable integration of grazing land and forestry
Windbreaks - planting of trees/shrubs to manage the effect of wind on erosion and soil moisture [source University of Illinois]

Agroforestry is most typically practiced on large individual sites, such as the farmlands and rangelands already discussed. But there are opportunities for it on all fertile land. For further information on agroforestry on a small scale, be sure to read the next page.

Agroforestry in Landscaping

Trees aren't the quickest growing plants. They take years to grow and mature, which means there isn't a lot of room for mistakes when planting them on the agroforestry level. The benefits each forester is hoping to realize depend on accurate and appropriate selection and care. To help in making the best determination possible, landowners should take part in a landscape assessment.

A landscape assessment will look at the condition of the land's resources within a larger planning area, determining the relationship between the landscape structure, environment and agroforestry options [source: Bentrup]. Your local resource agency or planning organization should be able to help you with an assessment.

There are several advantages small property owners could realize in relation to large-scale industrial forestry sites:

Planning around a small specific site will allow the landowner the opportunity of using his resources and climate conditions to the best of his ability.
The small scale could allow the landowner the opportunity to specialize in a specific kind of timber. This could create the chance at optimal profits along with the environmental benefits.
Having a small tree crop allows for more hands-on, specific management yielding better quality produce.
Trees provide many benefits that are not always thought of, such as wildlife habitats, aesthetic value and livestock shelter. These may be great assets to any size land.

There are several disadvantages small property owners could realize in relation to large-scale industrial forestry sites:

It could be challenging to get recognition and funding.
Smaller budgets make it hard to get the machinery or education on technique and practices.
Planting and maintenance are important factors and landowners may need to hire laborers.

It's more of a challenge to profit from small quantities of wood when harvesting and marketing are as costly as they can be [source: World Agroforestry Centre].

For more information on how to get even greener, visit the links on the next page.

Benefits

There are many options when choosing which trees a forester should consider. Here's an idea of the roles a few specific trees play:

Fertilizer trees - land regeneration, soil health, and food security
Fruit trees - bears fruit and provides the nutrition that comes with that
Fodder trees - improves smallholder livestock production
Medicinal trees - provides medicine [source: World Agroforestry Centre].

These are great examples, but remember that not all trees will work at a specific site.

Lots More Information

Sources

Bentrup, G., M Dosskey, and G. Wells. "Conducting Landscape Assessments for Agroforestry. USDA National Agroforestry Center. Accessed 11/23/2008. http://www.unl.edu/nac/agroforestrynotes.htm
Elevitch, C. R. and K. M. Wilkinson. "Economics of Farm Forestry: Financial Evaluation for Landowners." Agroforestry Guides for the Pacific Islands #7. 2000.http://www.agroforestry.net/afg/book.html
National Agroforestry Center. "http://www.unl.edu/nac/agroforestrynotes.htm
Natural Resource Conservation Service. "Fitting Agroforestry to the Landscape." United States Department of Agriculture. http://www.nrcs.usda.gov/NEWS/thisweek/2008/052108/techtip052108.html
Rietveld, B and K Irwin. "Agroforestry in the United States." USDA National Resource Conservation Service.1996. http://www.unl.edu/nac/agroforestrynotes.htm
University of Illinois Extension. "Agroforestry." Accessed 12/1/2008 http://web.extension.uiuc.edu/forestry/agroforestry.html
World Agroforestry Centre. "Introduction to Agroforestry." Accessed 11/23/2008. http://www.worldagroforestrycentre.org/Agroforestry.asp
World Agroforestry Center. "Our history: more than 30 years of agroforestry research and development." Accessed 11/30/2008. http://www.worldagroforestry.org/af1/index.php?id=77