3. Presentation Objectives
3
Define alley cropping
Describe the benefits
Explain the basic design
considerations
Identify potential crops
and species
Alley Cropping
4. What is Agroforestry?
4
…the intentional combining of
agriculture and working trees to
create sustainable farming systems.
Forest farming
Alley cropping
Alley Cropping
5. What is Alley Cropping?
5
… the planting of trees 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.
Poplar and wheat
Alley Cropping
7. Why use Alley Cropping?
7
Improves crop diversity, and economic returns
Increases net carbon storage in the soil and
vegetation
Improves utilization and recycling of soil nutrients
Provides or enhances wildlife habitat
Alley Cropping
8. Benefits
8
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
Alley Cropping
9. Benefits
9
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
Alley Cropping
10. Benefits
10
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
Alley Cropping
11. Benefits
11
Stops Soil Erosion
Trees stop soil erosion
Control the speed of water
Control wind erosion
Alley Cropping
12. Benefits
12
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
13. Design Considerations
13
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
Low
Pecan
Medium
Medium
Popular
Medium
High
Pine
High
Medium-high
Alley Cropping
14. Tree Criteria for Alley Cropping
14
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
Alley Cropping
15. Potential Trees
15
Walnut
Pecan
Pine
Pine
Poplar
Tropical:
Coffee
Coconut Palm
Papaya
Coffee
Walnut
Alley Cropping
16. Potential Alley Way Crops
16
Row/cereal crops (corn,
soybeans, milo, wheat)
Forage crops (legumes,
grasses)
Specialty crops (vegetables,
flowers)
Pecans and hay
Alley Cropping
17. For Additional Information
17
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
http://www.unl.edu/nac/alleycropping.htm
The Center for Agroforestry
http://www.centerforagroforestry.org/practices/ac.php
Association for Temperate Agroforestry
http://www.aftaweb.org/alley_cropping.php
The Overstory
http://agroforestry.net/overstory/osprev.html
Alley Cropping
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 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 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 enhancedecological goods and services provided. This system is used world-wide today.
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 earlyemphasis 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.
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.
Whatare 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.
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.
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 75-200 million metric tons of atmospheric carbon per year by using current best management practices. US grazing land can sequester 30-90 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).
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 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. Utilizea 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 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.
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.
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.
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.
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.