In the 1800s, the first settlers of Wisconsin battled its dense forests to establish the open farmland that now sprawls across much of the state.
But, by utilizing agroforestry techniques, many farmers can use trees and cultivate them alongside crops to maximize the potential of both.
Alley cropping is one such technique, a topic explored by a webinar hosted by the Center for Agroforestry, headquartered in Missouri.
Alley cropping can be characterized as the planting of rows of trees or shrubs wide enough to create alleyways where agronomic or forage crops can be planted or produced.
For example, a farmer may establish two rows of pecan trees about 8-10 yards apart and in this open space they can plant six rows of corn. The arrangement benefits both species.
“The design of an alley cropping practice begins with identifying your objectives,” said Gene Garrett, a forestry professor emeritus with the University of Missouri. “Are you implementing an alley cropping practice to grow timber or other products? For erosion control or to provide more wildlife habitat? Your objectives will determine how you plan your alley cropping practice.”
In short, Garrett said, agriculturists need to consider the incline, sunlight, wind orientation, location of nearby roadways, as well as the type of trees, crop types, row spacing, precipitation and other factors when they cultivate an alley cropping.
It can take years for the process to come to fruition and little nuances — such as whether shade trees grow in such a way as to foster strong lumber in the alley trees, or if they grow too quickly and stunt lumber growth — can be the difference between success and failure.
“The short term success of any alley cropping practice is determined by the combination of trees and crops planted,” agronomist David Lindell said. “Some alley cropping practices are designed where trees of different species and less responsive to light are grown on either side of the desired species. This creates a triple row of trees.”
“When deciding on what trees to plant, ask yourself the following question: What trees do well in my area?” Garrett said. “Consider growing conditions, such as soil and climate as well as the potential markets for your products. The tree species you select should be marketable, both the wood itself and other products, such as nuts or fruit, which would give you another source of income. The trees should also be compatible with the companion crops or forestry you choose.”
The benefits of alley cropping are numerous and varied. If implemented correctly, the practice can:
- Reduce soil erosion. This is especially true in sloping areas.
- Improve crop performance. Trees and shrubs contribute organic matter, which increases soil productivity. By positioning trees correctly, alley cropping can also create a microclimate from the increased shade and reduced wind, which in turn increases water use efficiency by crops.
- Reduce use of chemical fertilizers and pesticides. Alley cropping curbs weed growth and increases nutrient flow, which improves soil quality without the use of fertilizers.
- Minimize nitrogen leaching. Even past the cropping root zone, nitrogen is captured by deeper tree root systems. This improves water quality.
- Promote biodiversity. Diverse plantings offers more wildlife with more habitat potential.
- Increase profits. Crop yields may likely benefit, while alternative offerings — such as, say, nut production or lumber — can provide additional income for the homestead.
It’s also important to remember that alley cropping requires maintenance. Trees need to be pruned in order to grow in a way that benefits the other plants and trees in the alley cropping. Weeds need to be dealt with. Spacing between species. needs to be maintained. Fertilization needs to be utilized, especially for fruiting and nutting trees.