1. An Agroforestry Practice
Alley Cropping
An Agroforestry Practice
Welcome. This presentation will cover one of the five recognized agroforestry practices currently being adopted and used in the US and its territories – alley cropping.
This presentation was developed by the USDA National Agroforestry Center

2. Presentation Objectives
Define alley cropping
Describe the benefits
Explain the basic design considerations
Identify potential crops and species
This presentation will define alley cropping, describe some of its major benefits, explain basic design considerations, and identify selected potential crops and plants that are or can be used in an alley cropping system.
Alley Cropping

3. What is Agroforestry?
…the intentional combining of agriculture and working trees to create sustainable farming systems.
Riparian buffer
Forest farming
Alley cropping is an agroforestry practice. But what is agroforestry? Although there are many definitions on agroforestry one of the simplest definitions is the intentional combining of agriculture and working trees to create sustainable farming systems. In agroforestry systems, trees or shrubs and their products are intentionally used within agricultural systems, livestock, or forests and are cultured with woody plants (e.g. trees and shrubs). Knowledge, careful selection of species, and good management of trees and crops are needed to optimize the production and positive effects within the system and to minimize negative competitive effects. Agroforestry systems can be advantageous over conventional agricultural and forest production methods through increased productivity, improved economic benefits and social outcomes and the enhanced ecological goods and services provided. This system is used world-wide today.
Silvopasture
Alley cropping
Windbreaks
Alley Cropping

4. What is Alley Cropping?
… the planting of trees or shrubs in two or more sets of single or multiple rows with agronomic, horticultural, or forage crops cultivated in the alleys between the rows of woody plants.
What is alley cropping? Again there are many definitions for this term in use today but basically alley cropping is the planting of trees or shrubs in two or more sets of single or multiple rows with agronomic, horticultural, or forage crops cultivated in the alleys between the rows of woody plants. This approach is sometimes also referred to as intercropping. The foundation for alley cropping dates back to 17th century (perhaps earlier) Europe and Asia. Even earlier use of this concept occurred with many Native American groups. This concept was brought to North America where most of the early emphasis and research focused on pecan and black walnut alley cropping or intercropping applications. Today research is expanding into other systems. There are many other numerous potential tree, shrub, and crop combinations. Alley cropping can be used on any lands where crops or forages are grown and adapted trees or shrubs are available to provide either economic and/or environmental benefits to the field. In many instances, alley cropping can be used to convert marginal cropland to a permanent land use cover that incorporates Working Trees. In other cases alley cropping can be designed for both long term crop or forage production with tree production.
Poplar and wheat
Alley Cropping

5. Alley Cropping is not….. Corn with two pecans
Alley cropping is not just crops and trees randomly growing in a field – it is more that, it’s a system that is intentional, integrated, and interactive.
Corn with two pecans
Alley Cropping

6. Why use Alley Cropping?
Improves crop or forage quality and quantity by enhancing microclimate
Improves crop diversity, and economic returns
Increases net carbon storage in the soil and vegetation
Improves utilization and recycling of soil nutrients
Decreases off site movement of nutrients or chemicals
Provides or enhances wildlife habitat
What are the benefits of an alley cropping system? Working Trees in an alley cropping system cycle nutrients from deeper in the soil profile by shedding organic matter on the surface as leafy and woody litter or 'green manure'. Litter rebuilds a soil's structure making it less erodible and more able to absorb and hold water. Alley cropping can also yield other products such as vegetables, bioenergy feedstock, and fodder. They create a more favorable growing conditions for the alley (intercrops) crops by shielding them from drying winds and enhancing microclimates. Alley cropping systems planted on slopes, anchor the soil, trap chemicals, and form terraces, preventing the loss of precious topsoil by heavy rains and the overland flow of water. In addition alley cropping creates diversity in habitat structure for wildlife including birds, mammals, and beneficial insects.
Alley Cropping

7. Benefits
Improves crop or forage quality and quantity by enhancing microclimate
Improves the microenvironment to increase crop yields
Protects alleyway crops from physical damage from winds or from soil particles blown into the plant tissue which bruises or degrades quality
Lets take a more detailed look at alley cropping benefits. Alley Cropping can reduce crop evapotranspiration by 15 to 30% and increase water content in the tillage layer by 5 to 15%. Some crops are sensitive to damage from wind or from sand particles blown into the fleshy tissue of the plant which bruises or degrades quality. Many fruits and vegetables fall into this category. Many crops including traditional row crops may show a 10 to 20% in yield depending upon the crop and spacing distance.
Black walnut with hay
Alley Cropping

8. Benefits Improve Crop Diversity, and Economic Returns
Allows production of annual crops for needed cash flow while at the same time growing longer term woody investments.
Allows two annual crops to be grown on the same acreage such as a forage or row crop and nut or fruit crops
Allows crop diversity which reduces risk
Because alley cropping is a layered system that uses vertical as well as horizontal spaces, land owners can integrate a variety of different crops which increases crop diversity and improves economic returns compared to stand alone systems. This allows production of annual crops for needed cash flow while at the same time growing longer-term, woody plant derived investments. In addition, because of the vertical, layered system structure, the system can allow two or more annual crops to be grown on the same acreage such as a forage or row crop and nut or fruit crops. Finally multiple crops create economic diversity and this helps reduce financial risk.
Taro
Elderberry
Alley Cropping

9. Benefits Increases net carbon storage in the soil and vegetation
Roots, crop residue, leaves and forage add to soil carbon
Tree component adds to total potential carbon stored on site through long term sequestration in the above ground and below ground biomass
US forestlands currently fix about 250 million metric tons of atmospheric carbon each year. With terrestrial ecosystems, the soil stores the greatest amount of soil carbon and due to past agriculture activities much of this carbon has been lost. Restoring soil organic carbon on depleted soils is the fastest way to sequester carbon. Adding a tree component to the management of the land increases the potential of carbon storage. US cropland can sequester about million metric tons of atmospheric carbon per year by using current best management practices. US grazing land can sequester million metric tons of atmospheric carbon annually by controlled grazing, fire management, and by use of fertilizers and improved cultivars. Alley Cropping adds the woody dimension to accumulate long term above ground biomass (carbon) storage to cropland or grasslands in addition to adding soil organic matter(carbon).
Alley Cropping

10. Benefits Improves utilization and recycling of soil nutrients
Tree roots are generally deeper than crop roots
Nutrients and chemicals that pass through crop root zone are intercepted by trees
Nutrients are utilized by the trees and recycled back to the soil surface by leaf drop
The tree roots travel much deeper than the annual crops for their moisture and nutrients. In fact, a mathematical model developed for the Victoria Road site in Oregon has predicted that nitrate leaving the rooting zone is reduced by 50% when compared to a barley crop without trees. In addition, tree roots can intercept crop nutrients not utilized by the annual crop, that would otherwise leach down into the ground water.
Alley Cropping

11. Benefits
Decreases off site movement of nutrients or chemicals - surface
Trees planted on contour trap sediment and residue along with attached nutrients and chemicals
Infiltration increases in tree rows decreasing overland flow and associated movement of soluble nutrients and chemicals off site
Trees planted on contour trap sediment and residue along with attached nutrients and chemicals. Infiltration increases in tree rows decreasing overland flow and associated movement of soluble nutrients and chemicals off site.
Alley Cropping

12. Benefits
Decreases off site movement of nutrients or chemicals - subsurface
Tree roots are generally deeper than crop roots
Nutrients and chemicals that pass through crop root zone are intercepted by the woody plants
Nutrients are utilized by the woody plants and recycled back to the soil surface
Tree roots are generally deeper than crop roots. Nutrients and chemicals that pass through crop root zone are intercepted by trees and shrubs. Nutrients are utilized by the woody plants and alley crops and recycled back to soil.
Alley Cropping

13. Benefits Provides or enhances wildlife habitat
Provides food and cover through a diversity of plants
Creates vertical habitat structure
Improves pollinator foraging and nesting habitat
Builds travel corridors for wildlife movement to connect to other food, cover, or water resources
Alley cropping improves wildlife habitat by providing food and cover through a diversity of plants; creating vertical habitat structure; improving pollinator habitat; and building travel corridors for wildlife movement to connect to other food, cover, or water resources. To maximize wildlife benefits: Utilize native species that mirror those you would find in the natural ecosystem when possible. Select species that provide cover and food. Utilize a mixture of trees and shrubs to help provide vertical structure to the habitat. For most wildlife, wider is generally better. Also connect the woody rows to areas of other important habitat if possible.
Alley Cropping

14. Alley Cropping - Issues
Involves intensive management
May remove land from annual production, depending on the tree crop
May complicate herbicide application
Requires marketing infrastructure for woody plant products
Since alley cropping is a system that involves multiple crops and vertical and horizontal spaces, there are issues and topics that should be addressed and considered. Alley cropping may require a more intensive management system including specialized equipment for the woody plant management and additional managerial skills and training to manage multiple crops on a given site; it may remove land from annual crop production and may not provide a financial return from the woody plants for several years; herbicide application when herbaceous and woody plants are close to each other requires accurate application; and will require a marketing infrastructure for the woody plant products that may not be present in some agricultural communities or areas.
Coffee under macadamia trees
Alley Cropping

15. Design Considerations
Light requirement for the crop or forage to be grown in the alley way
Root Competition between crops
Type and size of the equipment being used
Tree Species
Shade
Produced
Root
Competition
Black walnut
Low
Pecan
Medium
Oak
High
Pine
Medium-high
Alley cropping can be used on any lands where crops or forages are grown and adapted trees or shrubs are available to provide either economic and/or environmental benefits to the field. In some instances, alley cropping can be used to convert marginal cropland to a permanent forest cover. In other cases alley cropping can be designed for both long term crop or forage production with tree production. Competition for light, water and nutrients between the tree and the intercropped species not only affects the yields of the alley crop but also the growth of the trees. Three critical design considerations for any alley cropping system are the light requirements for the crop or forage to be grown in the alley way, the amount of root competition between crops and the type and size of the equipment that will be used. Consideration should be given to using multiples of the widest field equipment width as the guide for determining alley widths.
Alley Cropping

16. Tree or Shrub Criteria for Alley Cropping
Marketable
Yields annual or periodic commercial product (wood, nuts or fruit)
Appropriate shade for the alley crop
Minimal roots at soil surface
Adapted to site and soils
Foliage residue does not interfere with alley crop
Growth requirements complement alley crop
Trees and shrubs used in alley cropping systems are usually selected because they have a combination of one or more of the following traits: marketable, yields an annual or periodic commercial product (wood, nuts or fruit), appropriate shade for the alley crop, minimal roots at soil surface to interfere with alley crop, adapted to site and soils, foliage residue does not interfere with alley crop, and growth requirements complement the alley crop.
Alley Cropping

17. Potential Trees Walnut Pecan Chestnut Pine Poplar Tropical: Coffee
Coconut Palm
Leucaena
Eucalyptus
Papaya
Pine
Coffee
There are a numerous potential trees that can and are being used in alley cropping systems. The type of tree varies from geographic region and the available markets that are present.
Walnut
Leucaena
Alley Cropping

18. Potential Shrubs Hazelnut/filbert, (nuts)
Willow, dogwood (decorative florals)
Chokecherry, highbush cranberry, currant, elderberry, saskatoon, gooseberry, sugar apple, pomegranate (fruits)
Hazelnut
As with trees, there are a numerous shrubs that can and are being used in alley cropping systems. The type of shrub also varies from geographic region and the available markets that are present. Two topical and sub tropical shrubs that can be used include sugar apple and pomegranate. Anon (sugar apple) is a sweet pulpy tropical fruit with thick scaly rind and shiny black seeds. A pomegranate is a fruit-bearing deciduous shrub or small tree growing to between five and eight meters tall. The saskatoon (Amelanchier alnifolia Nutt.) is a fruit bearing shrub native to the southern Yukon and Northwest Territories, the Canadian prairies and the northern plains of the United States.
Willow
Sugar apple
Saskatoon
Pomegranate
Alley Cropping

19. Potential Alley Way Crops
Row/cereal crops (corn, soybeans, milo, wheat)
Forage crops (legumes, grasses)
Specialty crops (vegetables, fruits, flowers, medicinals)
Biomass (energy, feedstock)
As with plants in the woody sets, the alley way crops are open to almost any crop. Major crop groups that can be used include row or cereal crops, forage crops, specialty crops, and biomass crops.
Biomass alley crop
Pecans and hay
Alley Cropping

20. For Additional Information
Where is there more information on alley cropping?
A number of web sites are available to provide more detailed information on alley cropping systems. Here are a few :
USDA National Agroforestry Center
The Center for Agroforestry
Association for Temperate Agroforestry
The Overstory
Where is there more information on alley cropping? A number of web sites are available to provide more detailed information on alley cropping systems. Here are a few: USDA National Agroforestry Center, The Center for Agroforestry, Association for Temperate Agroforestry, and the Natural Resources Conservation Service.
Alley Cropping

21. Summary – Alley Cropping
Increased crop production
Enhanced economic diversification
Improved crop protection
Better nutrient utilization
Improved soil and water quality
Coconuts and beans
Alley cropping is especially well adapted to meet the needs of today’s farms throughout the United States. For landowners who are interested in reducing the acreage being row cropped and adding woody crops for the purpose of preparing to pass their land to their non-farming children, it is the perfect practice. Likewise, for landowners who are not just interested in the production aspects of farming but also equally interested in environmental and conservation benefits, alley cropping can be designed to hold the soil and significantly reduce the loss of nutrients and pesticides. Moreover, for those interested in improving their wildlife habitat, establishing grasses, forbs and shrubs in direct association with the woody plant rows or in the alleyways can create enhanced wildlife opportunities. The strength of today’s alley cropping practice is its ability to meet multiple objectives, improving farm and ranch sustainability, increasing and diversifying income while conserving and protecting our natural resources and creating a new (alley) way to the future.
Lettuce intercrop followed with pumpkins
Pine and cotton
Alley Cropping

22. Acknowledgements
This presentation was developed by the USDA National Agroforestry Center (NAC), Lincoln NE. NAC is a USDA partnership between the U.S. Forest Service and the Natural Resources Conservation Service.
A partnership of:
National Agroforestry Center
This presentation was developed by the USDA National Agroforestry Center (NAC), Lincoln NE. NAC is a USDA partnership between the U.S. Forest Service and the Natural Resources Conservation Service.
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Alley Cropping