A bioeconomic decision model comparing composted and fresh litter for winter squash S.S. Andrews a, *, L. Lohr b , M.L. Cabrera c a Institute of Ecology, University of Georgia, Athens, GA, USA b Department of Applied and Agricultural Economics, University of Georgia, Athens, GA, USA c Department of Crop and Soil Sciences and Institute of Ecology, University of Georgia, Athens, GA, USA Received 29 March 1999; received in revised form 30 June 1999; accepted 6 July 1999 Abstract Decision aids are needed to identify management strategies for complex agricultural problems aecting numerous stakeholders. Our objective was to develop a bioeconomic decision aid examining poultry litter application to winter squash, Cucurbita maxima, on the basis of multiple goals: enhancing environmental and soil quality, maximizing waste recycling, and maximizing net revenues. Because farm-level decisions about waste management may con¯ict with community goals, the decision aid balances the preferences of squash growers, poultry producers, and community-level decision makers. The aid utilizes a simulation model that compares four litter management alternatives: (1) fresh poultry litter applied to meet crop nitrogen (N) needs; (2) fresh poultry litter applied to meet crop phosphorus (P) needs; (3) composted poultry litter to meet crop N needs; and (4) composted poultry litter to meet crop P needs. Output from biophysical submodels compares well to literature data. Sensitivity tests show strong correlation between nutrient accumulation in soil pools and estimates of potentially available nutrients in fresh and composted litter. The decision model outcome, when averaged across stakeholder groups, clearly favors composted litter applied to meet crop P needs. Decision aids can help various stakeholder groups see how their priorities interact as well as demonstrate the importance of long-term analysis to assess alternative management strategies. Published by Elsevier Science Ltd. Keywords: Decision making; Poultry litter management; Compost; Bioeconomic model 1. Introduction Most de®nitions of sustainable agriculture include the multiple goals of soil productivity, farm pro®tability, and environmental protection (Edwards, 1987; Lowrance et al., 1987; Schaller, 1993). However, various individuals and stake- holder groups will have dierent priorities or even con¯icting goals. Developing decision tools that address these multiple goals while maintaining the integrity of site-speci®c environmental issues is an important step toward achieving long-term sus- tainability (Hart, 1984; Schaller, 1993). The need to optimize on-farm recycling of ani- mal waste provides an example of how decision 0308-521X/99/$ - see front matter Published by Elsevier Science Ltd. PII: S0308-521X(99)00046-3 Agricultural Systems 61 (1999) 165±178 www.elsevier.com/locate/agsy * Corresponding author. USDA-ARS National Soil Tilth Laboratory, 2150 Pammel Drive, Ames, IA 50011, USA. Tel.: +1-515-294-9762; fax: +1-515-294-8125. E-mail address: andrews@nstl.gov (S.S. Andrews)