Share:Made in the shade

Agroforestry — combining woody plants with agriculture — yields many benefits

BY 

SARAH ZIELINSKI 

4:18PM, SEPTEMBER 18, 2015

An Ethiopian coffee farm is “a gorgeous forest with massive, old-growth trees in the canopy and these coffee plants that are a native species growing in theunderstory,” explains Evan Buechley. He’s a graduate student at the University of Utah in Salt Lake City. Buechley studies birds and conservation biology.

There's a bonus to growing coffee in a traditional way that preserves tall trees — and it's not just for the birds.

Scientists recently found a rich and diverse bird population living in the shade of forested coffee farms. Those farms are in the east African nation of Ethiopia. Ample birdlife is just one of many benefits of this type of farming, called agroforestry. The practice mixes in trees when growing crops or raising livestock.

Combining forest and farm provides habitat for many species of wildlife around the world. The practice can help keep waterways clean and soils healthy. This helps farmers and ranchers. Agroforestry is essential to producing one of the world’s favorite treats — chocolate. And it may even blunt the effects of climate change.

Thanks to growing recognition of its benefits, this ancient farming technique is gaining new attention.

In Ethiopia, agroforestry has been the standard way to grow coffee for more than a thousand years. The coffee plant, Coffea arabica, thrives in the shadows of tall trees. (The word “coffee” comes from the name of an old Ethiopian province named Kaffa.) To farm coffee, growers simply thin the forest of any competing plants. Experts prize the resulting shade-grown coffee beans.

Buechley and his colleagues recently conducted a census of birds on Ethiopia’s farms and in its forests. His team found something special: All the species of birds that could be found in the forest also were living on traditional coffee farms.

Despite its benefits, many farmers are reluctant to adopt agroforestry practices, says Jim Brandle. He is a professor of forestry at the University of Nebraska-Lincoln. People have a difficult time believing it’s worthwhile planting trees on land that could be sown with a profitable crop, he explains. Still, the idea is catching on. India, for example, announced in 2014 that agroforestry would lead its push to add more trees.

Border territory

Long before the technique got its name, humans had used agroforestry to grow plants. The basic idea behind agroforestry is the same, Brandle explains, whether it's in Africa or halfway around the world in the South Pacific. On Hawaii and other tropical islands in the Pacific Ocean, for instance, farmers have a history of cultivating forests filled with coconut, banana, breadfruit and other trees. Agroforestry is also common elsewhere, even in the continental United States.

These windbreaks are in North Dakota. The trees protect crops in the fields and reduce the amount of soil eroded by the wind. Those trees also store carbon.

USDA-NRCS

If you travel across America by car, bus or train, you’ll pass a lot of farms. You might see field after field of corn in Indiana, barley in Montana or soybeans in Iowa. In many places, a thin wall of trees will border a field. It’s called a windbreak. Although this looks very different from an Ethiopian coffee farm, windbreaks represent a form of agroforestry.

In fact, windbreaks may be one of the most easily recognizable forms of agroforestry in the United States. Planting trees along the edges of a field interrupts the wind, altering its speed, Brandle explains. Next to a windbreak, it’s a little warmer and less windy. Crops grow better in these sheltered areas. The trees also help to protect the soil from wind erosion.

Another common type of agroforestry in the United States takes place along what are called riparian (Ry-PAIR-ee-un) zones. These are regions along the banks of rivers and streams (ripa is Latin for river bank). To create a buffer — or protected area — farmers plant trees and other types of vegetation here. This vegetation helps limit erosion. The plants also provide food and habitat for birds and other wildlife. And the greenery helps prevent rains from washing sediment, nutrients and pesticides away into nearby streams...

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