Final Report for LS05-179
A series of focus groups in the Western Gulf states of the U.S. determined that future research on litter application to forests should focus on generating information that improves the ability of forest and broiler house owners to predict cost-effectiveness, pine yields, water quality, and wildlife forage quality associated with this practice. As a result, the research and extension team of this planning project will develop a SARE research and education project proposal to observe these variables in response to forest litter application conducted over a variety of soil types, forest ages, forest densities, and forest management intensities.
The goal of this planning project is to initiate a process for designing economically feasible and environmentally sound methods of disposing and utilizing poultry litter in forests of the Western Gulf region. To accomplish this goal, this planning grant will be used to:
1. Identify and prioritize the environmental and economic issues that are critical to application of poultry litter in forests and deficiencies in parlaying research information about poultry litter application to forest managers, forest landowners, and poultry producers of the region. This will be done by soliciting input from regional forest landowners, poultry producers, researchers, extension specialists, and other stakeholders. Particular attention will be given to actively seeking input from traditionally underserved landowners in the region.
2. Organize an inter-disciplinary team of researchers, extension specialists, forestry consultants, forest landowners, and poultry producers to develop a set or researchable questions and outreach protocol based on issues that arise from Objective 1. This will be done through workshops, conference calls, and on-site interviews with landowners interested in boosting forest productivity and poultry producers interested in new avenues of waste disposal.
3. Develop a SARE Research and Education grant proposal that will outline a research project and outreach programs based on the issues that arise from achieving objective 2. The project will potentially produce: (a) economically feasible poultry application protocol for pine forests of the Western Gulf, (b) broad understanding of the ecological sustainability of applying litter to forests, and (c) methods for efficiently teaching application concepts and methodology to forest landowners, managers, and poultry producers.
Poultry production and processing are vital to the rural economies of the southeastern US, contributing $14.6 billion to the region each year. The Western Gulf region (Arkansas, Louisiana, Mississippi, Oklahoma, Texas) has a particularly high concentration of broiler production facilities, with some areas of the region producing as much as 150,000 to 225,000 chickens per year. A substantial amount of waste material is produced by this industry; 7 million tons of poultry litter (a mixture of manure and bedding material) is generated in the United States annually. In Arkansas, the top poultry-producing state in the Western Gulf, approximately 5,000 tons of litter is produced daily (Holleman 1992).
Poultry litter contains several nutrients that enhance plant growth, so litter has been commonly utilized in pastures and other agroecosystems as fertilizer. Forage yields have been shown to increase from 40 to 433% in response to varying levels of broiler litter application in the Western Gulf region (Evans 2000). The price of broiler litter is typically half that of inorganic, commercial grades of fertilizer. In addition, although prices of commercial fertilizer increase in tandem with natural gas prices due to its manufacturing process, broiler litter prices do not necessarily follow natural gas price trends.
Several negative environmental consequences associated with long-term litter application are limiting the agricultural land base available for poultry litter application. Soil concentrations of nitrogen (N) and phosphorus (P) have been shown to increase with repeated poultry litter applications. Through leaching and runoff, N and P pollute surface and groundwater (Kingery et al. 1994). High buildups of N and P in surface waters as a result of livestock production have been shown to cause algal blooms that harm aquatic life (Sharpley et al. 1994). As a result of these potential negative effects of poultry litter disposal, the US Environmental Protection Agency has implemented regulations that require many poultry operations to develop N- or P-based nutrient management plans. These plans, along with individual state regulations, are expected to reduce poultry litter application rates below that historically used for forage production. In addition, concentrations of arsenic, a human carcinogen, are often high in poultry litter as a result of compounds added to feed to control internal parasites (Jackson et al. 2003). Agriculture soils treated with poultry litter have been found to have 6.4 times higher levels of arsenic than nearby unamended forest soils (Rutherford et al., 2003). Repeated application of poultry litter can also raise concentrations of metals such as cadmium, copper, manganese, and zinc (Kingery et al. 1994). These elements have the potential to contaminate surface and groundwater via runoff and leaching (Sims and Wolf 1994).
Because poultry production is continuing to increase while legal application rates and the land area conventionally used for application are expected to decline, it is essential to explore new means for disposing of poultry litter. Application of poultry litter to pine plantations could be an attractive alternative to current disposal methods. Southern pine forests are abundant in the Western Gulf region and contribute substantially to its economy. For example, Louisiana’s forests constitute its top crop, contributing approximately $3 billion to its economy each year (LFA 2002). Forest products rank in the top five commodities in each of the five Western Gulf states. Inadequate soil nutrition is the primary limitation to production of the most economically important southern pine species, loblolly pine (Jokela et al. 2004). Consequently, dramatic gains in loblolly pine growth of up to 300% have been found in response to fertilization (Tiarks and Haywood 1996). However, nutrient amendment with commercial fertilizer costs approximately $100 per acre, and the cost of forest fertilization is carried for 10 to 20 years due to the length of southern pine rotations. These economic factors make fertilization cost-prohibitive for small private forest landowners that have low capital to invest in forest management. The lower cost of poultry litter may enable smaller forest landowners to economically enhance the wood and fiber yields of their forests through fertilization. In addition, pine plantations should be attractive sites for litter application because they have extremely high nutrient retention capacities and high infiltration rates which reduce surface water runoff. Furthermore, forests are typically managed for products that do not enter the human food chain. Therefore, long-term litter applications to forests may reduce current risks associated with applications to pastures and annual crops. Thus, litter application to forests of the Western Gulf has the potential to enhance income of smaller rural forest landowners in the region without threatening sources of water and food.
Poultry litter application to forests could become a widely accepted forest management practice if application methods that are environmentally sound and economically feasible are developed. This planning project would initiate the process of creating and assessing such methods. Although a few studies have investigated the effects of diverse rates of litter application on southern pine growth (Gaston et al. 2003, Clason and Blazier 2004), no comprehensive studies of the environmental impact and economic feasibility of applying litter to a range of forests in the Western Gulf region have been conducted. To properly identify the operational and economic constraints to adoption of litter application in forests, it is imperative to engage forest landowners, poultry producers, extension specialists, and economists in the earliest stages of research planning. Likewise, it is essential to organize teams of researchers in the Western Gulf region from a wide array of disciplines such as forestry, hydrology, soil science, microbiology, and wildlife to determine the pertinent environmental issues to be addressed by a comprehensive study of litter application. This planning project was used to engage these groups, and the outcome of this project will lead to the creation of a SARE proposal that will (1) test the effectiveness of diverse litter application methods in promoting southern pine forest productivity, (2) assess the soil, water, plant, wildlife, and microbial dynamics that are affected by litter application, (3) test the economic returns and feasibility from different litter application methods, and (4) develop functional, efficient methods for disseminating results and appropriate recommendations to stakeholder groups that can most benefit from knowledge regarding applications of poultry litter on pine plantation land in the Western Gulf region.
Gaston. L., Clason, T.R., and Cooper, D. 2003. Poultry litter fertilizer on pasture, silvopasture and forest soils. La. Agric. 46(3):22-23.
Clason, T.R., and Blazier, M.A. 2004. Poultry litter application to loblolly pine silvopastures. La. Ag. Commod. Dev. Meeting. January 16, 2004, Baton Rouge, LA.
Evans, H.E. 2000. Application of poultry litter and commercial fertilizer in a loblolly pine-bahiagrass silvopasture. M.S. Thesis. Stephen F. Austin University, Nacogdoches, TX.
Holleman, J.T. 1992. In Arkansas which comes first: the chicken or the environment. Tulane Env. Law. J. 6: 22-34.
Jackson, B.P., P.M. Bertsch, M.C. Cabrera, J.J. Camberato, J.C. Seaman, and C.W. Wood. 2003. Trace element speciation in poultry litter. J. Environ. Quality 32: 535-540.
Jokela, E.J., Dougherty, P.M, and Martin, T.A. 2004. Production dynamics of intensively managed loblolly pine stands in the southern United States: a synthesis of seven long-term experiments. For. Ecol. Manage. 192: 117-130.
Kingery, W.L., C.W. Wood, and D.P. Delaney. 1994. Impact on long-term land application of broiler litter on environmentally related soil properties. J. Environ. Qual. 23: 139-147.
Louisiana Forestry Association (LFA). 2002. Forest Facts. Retrieved June 20, 2003 from
Rutherford, D.W., A.J. Bednar, J.R. Garbarino, R. Needham, K.W. Staver, and R.L. Wershaw. 2003. Environmental fate of roxarsone in poultry litter. Part II. Mobility of arsenic in soils amended with poultry litter. Environ. Sci. Technol. 37: 1515-1520.
Sims, J.T. and D.C. Wolf. 1994. Poultry waste management: Agronomic and environmental issues. Adv. Agron. 50: 1-83.
Sharpley, A.N., S.C. Chapra, R. Wedepohl, J.T. Sims, T.C. Daniel, and K.R. Reddy. 1994. Managing agricultural phosphorus for protection of surface waters: Issues and options. J. Environ. Qual. 23:437-451.
Tiarks, A.E., and Haywood, J.D. 1996. Site preparation and fertilization effects on growth of slash pine for two rotations. Soil Sci. Soc. Am. J. 60: 1654-1663.
Between October 2005 and January 2006, a team of researchers and extension agents from Louisiana, Arkansas, Texas, and Mississippi were assembled to conduct this planning project. These personnel were experts in soil nutrition, poultry science, forest management, human dimensions, and economics. In January 2006, this research and extension team met to design focus groups that would ascertain environmental and economic issues of forest litter application important to the region’s stakeholders. A series of questions about environmental issues, economic feasibility, application technology, social and policy issues, and extension and outreach issues associated with litter application to forests was designed for the focus groups.
A series of focus groups were hosted in Louisiana, Arkansas, and Texas in April, October, and November 2006, respectively. The Louisiana meeting was hosted in Ruston, LA at a hotel conference hall, the Arkansas meeting was hosted in Booneville, AR at a USDA research station, and the Texas meeting was hosted in Overton, TX at a Texas A & M University research center. For each focus group, the research and extension team invited landowners and professionals of the state that had a stake in the forest litter application issue. Attendees at all focus groups were from the following categories: (1) poultry producers (which included private broiler house owners and integrator executives), (2) poultry litter applicators, (3) non-industrial private forest landowners, (4) forestry professionals (which included private forestry consultants, state agency foresters, and federal agency foresters), (5) wildlife professionals (which included wildlife agents from state and federal agencies), (6) soil scientists (which included scientists from state and federal agencies), and (7) environmental protection policy-makers (which came from state environmental quality protection agencies). At least two people from each category attended each meeting.
Focus group format consisted of a one-hour overview presentation given by the investigators of poultry litter’s value as fertilizer, poultry litter volumes and application trends in Western Gulf states, forest land area and uses in the Western Gulf, and research results from all studies in the southeastern United States on litter application to forests. Following this overview, attendees were given lunch then divided into 2 groups. Each group contained an attendee from each of the categories mentioned above. These groups were then asked the questions developed by the research and extension team by a facilitator, and their responses were recorded by the facilitator on a flip-chart, a transcriber on a note pad, and on a video. After these group discussions were completed, all attendees were brought back together and asked to comment on the responses to the focus group questions.
At the completion of all focus groups, group responses were summarized by a University of Arkansas at Monticello agricultural sociology program technician. The research and extension team then began meeting to discuss focus group responses and develop a full SARE research and education project proposal.
In all focus group sessions, participants agreed that litter disposal was becoming a pressing issue due to watershed impairment. Northwest Arkansas currently has the greatest level of impairment, with several watersheds listed as nutrient-impaired. East Texas and north Louisiana had comparable levels of watershed impairment, with one to two watersheds listed as nutrient impaired. In all regions, phosphorus of poultry litter origin is the likely contributor.
Participants also mentioned that their regions have abundant forestland in the watersheds that could serve as alternate sites for litter application. Participants identified several potential benefits of applying litter to forests. Benefits mentioned in all focus groups included the potential to distribute litter over a larger land area to dissipate nutrient buildups and the ability to reduce complaints about litter odor due to the farther distance of most forests from houses. However, numerous gaps in our knowledge base about litter application to forests were identified. The cost effectiveness of this practice is largely unknown because more information is needed about: (1) pine growth and yield improvements over a variety of soil types, forest ages, forest densities, and forest management intensities, and (2) litter application costs (which are unknown primarily because current litter application equipment is not adequate for traversing most forests). Growth and yield of forests in response to litter application is less known in northwest Arkansas than in other regions because forest fertilization is a relatively uncommon practice in that region. Potential impacts on water quality were also identified as a high concern because more watersheds originate in forests than in pastures. It was perceived that despite the current level of water quality research done on this topic, more comprehensive studies of the nutrient pollution potential of this practice is needed, with a wide variety of soil types, forest ages, forest densities, and forest management intensities accounted for with future research. Participants mentioned that such water quality research would be necessary to develop ecologically permissible total maximum daily loads of phosphorus for forests. Another vital research topic identified by the participants was the potential to alter the species composition and nutrient contents of understory vegetation with forest applications of litter and its associated impact on wildlife. Participants mentioned that extension and outreach efforts associated with forest litter application should be in the form of quarterly newsletters to stakeholders, emails, websites, extension bulletins, and field days (although field days were given lower priority than other forms of communication). Currently the research and extension team of this project, which will be bolstered by the professionals that supported this project by developing and participating in the focus groups, is drafting a full SARE research and education project proposal integrating the research and outreach topics mentioned above.
Educational & Outreach Activities
A paper for the Journal of Forestry detailing the focus group responses is being developed from this planning project.
The meetings held for this project were the first of their kind in that they drew experts and interested stakeholders from throughout the Western Gulf states to discuss issues associated with litter application to forests. The knowledge base generated about litter application to forests will be invaluable in guiding the development of future research projects on this topic. Future projects promise to generate information that will allow land owners and professionals of the region predict cost-effectiveness, yields, water quality, and wildlife forage quality of litter-fertilized forests over a wide range of soil and forest conditions. With the ability to predict these responses, litter application to forests may become more commonplace and water quality of watersheds of the region may be better protected and/or improved. In conducting this planning project, the investigators have also formed potential research and extension partnerships with several forest owners and poultry producers. Participation of these individuals in new research and demonstration projects may hasten the adoption of litter fertilization if research continues to show its economic feasibility.
A landowner that owns intensively managed forest land and broiler houses attended the Arkansas workshop. As a result, he may fertilize his forest with poultry litter and is interested in partnering with the research and extension team of this planning project for a research and demonstration project.
Areas needing additional study
Several gaps in our knowledge base about litter application to forests were identified by focus group participants. The cost effectiveness of litter application to forests is largely unknown because more information is needed about: (1) pine growth and yield improvements over a variety of soil types, forest ages, forest densities, and forest management intensities, and (2) litter application costs (which are unknown primarily because current litter application equipment is not adequate for traversing most forests). Growth and yield of forests in response to litter application is less known in northwest Arkansas than in other regions because forest fertilization is a relatively uncommon practice in that region. Potential impacts on water quality were also identified as a high concern because more watersheds originate in forests than in pastures. It was perceived that despite the current level of water quality research done on this topic, more comprehensive studies of the nutrient pollution potential of this practice is needed, with a wide variety of soil types, forest ages, forest densities, and forest management intensities accounted for with future research. Participants mentioned that such water quality research would be necessary to develop ecologically permissible total maximum daily loads of phosphorus for forests. Another vital research topic identified by the participants was the potential to alter the species composition and nutrient contents of understory vegetation with forest applications of litter and its associated impact on wildlife.