Evaluating Forestry Product Quality: Agroforestry Systems to Produce Alternative Complimentary Crops

David Brauer, ARS/USDA, Booneville, AR
Catalino Blanche, ARS/USDA, Booneville, AR
Charlie Feldhake, ARS/USDA, Beaver, WV
Carol Schumann, ARS/USDA, Beaver, WV

Agroforestry is an integrated land management program that yields an agricultural crop and a woody product. Successful agroforestry management practices will yield income from lands planted to trees many years in advance of harvesting wood products. As such, agroforestry is usually a more intensive landscape management than those yielding either agricultural or wood products alone because practices need to be adjusted to account for effects on both the agricultural and wood production. The objectives of this report are: 1) to present the reasons why landowners would be interested in developing farm wood lots for production; 2) to describe how agroforestry practices could be utilized to generate income throughout the life of tree plantations; and 3) to describe the agroforestry related research at Agricultural Research Service (ARS/USDA) locations in Beaver WV and Booneville AR.

Interest in Forestry Products

There are several reasons to anticipate that wood products will be a growth industry into the foreseeable future and appropriate for many landowners, including those with limited resources. First, the climate in the southeastern U.S. is good for the production of many hard- and softwood tree species. Second, there is an abundance of trees on privately owned land in the southeastern U.S. For example, there are about 10 million acres of privately owned forested land in Kentucky, approximately 40 % of the land area (Kentucky Division of Forestry Website, http://www.nr.state.ky.us/nrepc/dnr/forestry/dnrdof.html). A similar proportion of the land area in Alabama, Arkansas, Louisiana, Mississippi, Missouri and Tennessee is privately owned forests (Zeto 1999). Currently, forestry is big business throughout the seven state region. Sales from forestry products amounted to $3 billion to $10 billion in 1995 for each state in the region (Zeto 1999). Finally, the demand for wood products, especially for small diameter wood, is projected to grow until the year 2040.

Challenges to Making Income from Wood lots

The value of a wood lot varies considerably depending on the tree species present. The trees present in many wood lots in the region are of marginal timber value and may only have value as firewood. Therefore, many landowners will either selectively harvest or clear-cut their current tree stands in order to increase farm income in the future. Tree establishment represents about half of the cost of wood production whether landowners are replanting into recently harvested tree stands or establishing new ones (Pearson et al. 1995). Many landowners, especially those with limited assets and/or income, are reluctant to invest in tree plantings for wood products without the prospects of generating income before tree harvests 10 to 40 years in the future.

Agroforestry is one solution to the problem of lack of income in the years immediately after planting trees. Agroforestry is the combining of agricultural production with tree production on the same landscape. The objective of such practices is the production of a diversity of agricultural and forestry products that become available for harvest at different times. Both the agricultural and forestry components are managed, possibly intensively managed, in agroforestry systems.

There are five common types of agroforestry practices in North America: forest farming, alley cropping, silvopastures, windbreaks and riparian zone. In the first three practices, forest farming, alley cropping and silvopastures, the major objective is the production of an agricultural crop along side of trees. These three types of agroforestry practices are the focus of the research projects at the ARS locations in Booneville AR and Beaver WV. The major objective of windbreaks and riparian zones are conservation or environmental impact. Research regarding these two conservation agroforestry practices is on-going at other ARS locations including those at Columbia MO and Corvallis OR.

Agroforestry research at Beaver WV and Booneville AR is part of the agency's program directed towards small farmers and resource limited farms. Agroforestry research at the Booneville AR location is directed mainly towards crops that compliment pine plantations, whereas the research at Beaver WV focuses more on the systems that use hardwood tree species. The missions of the research programs at Booneville AR and Beaver WV are specifically directed towards regional small farmers. These agroforestry practices seem to be appropriate for small farms because many productions can utilize existing farm equipment and require inexpensive inputs. In addition, agroforestry yields a variety of products, some of which can be of high value. The sale of a diversity of products, some of high value, can increase the profitability of small farms.

Forest Farming

Forest farming can increase the profitability by increasing the value of products coming from forest farm lots. One forest farming system that the Booneville, AR location has researched most intensively is the production of pine needle straw. Pine needle straw has been in high demand in recent years. Pine needles make a good mulching material preferred by many landscape personnel because it is easier to work with than wood chip products. Construction companies also like pine needle straw because it spreads evenly, helps prevent soil compaction and retards sediment from leaving disturbed sites. Stands of pine trees including loblolly pines will produce harvestable quantities of needles 8 to 12 years after planting (Blanche and Carino 1998). Needles can be readily harvested using a standard hay rake and a hay bale that delivers rectangular bales directly to the rear of the machine. Both of these pieces of equipment are routinely found on many farms in the region. Most of the needles fall in the autumn (Blanche and Carino 1998), when work requirements of many farm operations are at a low point. These fallen needles contain plant nutrients that are usually available to the trees but are removed when needles are harvested (Blanche and Carino 1998). These nutrients should therefore be replaced by fertilizer additions, an expense of $10 to $30 per acre. With yields of 100 to 150 bales per acre, an acre of pine trees can produce $400 of income per year (Agricultural Research Service, 1996). Therefore, the income from pine needle straw harvests over the life of the trees can generate more income than that from timber sales (Pearson et al. 1995).

Researchers at the Beaver WV location are investigating another form of forest farming using a stand of mainly hardwood trees that naturally regenerated after clear-cutting 40 to 50 years ago. Less desirable trees in a portion of this forest were selectively removed to increase light penetration into the understory and decrease competition for more valuable tree species. Investigations to determine the feasibility of growing high value plants in the understory of this area have been initiated beginning the development of a production system for ramps (a wild relative of leeks native to Appalachia). An adjacent portion of this forest was clear-cut in 1998. A variety of tree species including paw-paw, Chinese chestnut and red oak have been planted in rows running east-west into the clear-cut. The paw-paw and Chinese chestnut will produce fruits and nuts, respectively, 10 to 20 years after planting. The red oak will be harvested as a high value veneer about 80 years after planting. The spaces in between the tree rows are being planted to brambles and blueberries for fruit harvest in 3 to 5 years.

Alley Cropping

Research is on-going at the Booneville AR location regarding alley cropping systems that compliment pine plantations. Alley cropping systems can be configured to produce income when in the first year after planting trees, because the space between tree rows are utilized to produce a crop. The possible alley cropping systems are endless if plans are made when the trees are planted. One considering alley cropping systems should plant trees in such a way to allow machinery access for crop production between the trees. For example, if a farmers has equipment to grow grain or sweet corn, an alley cropping system to continue such production can be devised by planting the trees in a configuration to provide alleys wide enough for crop production and machinery access.

Farmers should consider the production of phytochemical crops in alley ways. Phytochemical crops are grown to produce chemicals that have nutritional, pharmaceutical biological or industrial uses. The production of phytochemical crops is estimated to be a $7,000,000,000 industry and is growing at an annual rate of about 20%. Phytochemical crops that may be of value in alley cropping systems have been identified in USDA publications (Thomas and Schumann 1993) and a variety of fact sheets and booklets available from Appropriate Technology Transfer for Rural Areas (ATTRA). ATTRA can be reached weekdays during normal working hours by phone at 1-800-346-9140 or anytime via the internet at www.attra.org

The value of the crop is related to its phytochemical content. Shading and accompanied decreases in sunlight and temperature could have an effect, positive or negative, on phytochemical content, and thus crop value. In addition, post harvest handling and conditions can affect the phytochemical content of a crop. Many of these chemicals are light and/or heat sensitive. Thus exposure to excessive high temperatures or sunlight during harvesting and drying processes can reduce their value.

Probably the biggest challenge to the successful production of phytochemical crops is the marketing of the harvested crop. Most of these crops are marketed by a limited number of wholesales and retailers. The demand for the phytochemical crops may be limited by the ability of wholesalers and marketers to process the crop. Publications available from USDA (Thomas and Schumann 1993), fact sheets and booklets from ATTRA (see above), and the internet can be utilized to identify crops that have sufficiently large markets for a new producer to enter. Although the last two paragraphs describe some of the challenges to a farmer entering these markets, the potential to produce profits from phytochemical crops should serve as an incentive. One farmer in the Delta region of AR in 1998 was contracted to grow about 10 acres of catnip at an estimated value in excess of $100,000 (Hightower 1998).

Silvopastures

Silvopastures are probably the most common agroforestry practice in the southeastern U.S. Although the practice of combining grazing livestock with pine tree production may be common, such agroforestry systems often are not designed from the start. Efficiency of such systems can be enhanced if planned from the beginning. Trees can be incorporated into pastures to provide a multitude of benefits. Windbreaks both in pastures or near barns can reduce the livestock exposure to cold winds and blowing snow. Trees can provide shade which can reduce hot weather stress to livestock. Shade from trees can alter growth habit of forage growing in the understory. Evergreen trees can reduce frost damage in early spring, thus hastening spring grass growth. Shade can slow the maturation of cool season grasses growing beneath the tree canopy to extend the duration of spring grazing. Successful silvopastures require the landowner to consider both the tree and forage production systems during site development. Publications and assistance from the USDA's National agroforestry center (402-437-5178) and Grazing Land Technology Institute (817-334-5232) can be helpful in the design of silvopastures.

Summary

Forestry products can be readily produced in conjunction with complimentary crops in agroforestry production systems. These agroforestry systems have an advantage over traditional forestry production systems in that they can yield income generating products soon after tree plantings instead of waiting for tree maturation in 10 to 80 years. However, these systems require landowners to more intense land management and a greater magnitude of planning. A wide of array of agroforestry systems are possible. In most cases, an agroforestry system can be developed using existing on farm resources with labor being the major input necessary by the land owner. Therefore, land owners, even those with limited resources, should consider increased utilization of farm lots through agroforestry as a means of increasing farm income.

References


Mailing address for this author:  David Brauer’s and Catalino Blanche’s mailing address: USDA-ARS, 6883 S. Highway 23, Booneville, AR 72927

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