|Carroll, C Ronald - UNIVERSITY OF GEORGIA|
Submitted to: Ecological Applications
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: November 21, 2000
Publication Date: N/A
Interpretive Summary: Properly designed indices can help farm managers use scientific information to guide land management decisions. Our objective was to reduce a large existing soil data set into a representative index of soil quality that is easily interpretable by land managers. We developed a soil quality index to assess alternative poultry litter management practices using soil physical, chemical, and biological indicator data. We used the index to evaluate the effects of applying either fresh broiler litter or composted litter at two different rates at two pasture sites that differed primarily by soil type and climate. A common framework was used for the index at each site but different indicator variables were used to accommodate local conditions. The common criteria for evaluating indicator performance were the management goals at each site: maximizing litter disposal, maximizing forage yield, and minimizing environmental risk. Results from soil analyses showed significant differences between management alternatives. However, some of these results were conflicting such that further synthesis was needed to make the information useful in guiding management decisions. The data reduction technique coupled with the soil quality index appear to be effective monitors of sustainable management. Index results can easily be combined with social and economic information to provide broad guidance in assessing sustainability of agricultural management practices.
Technical Abstract: Scientists can evaluate the effects of management actions on agroecosystems but farm managers often lack the tools to effectively use this information for making decisions. Integrative indices of system health and sustainability may help solve this problem and provide the tools needed to guide land management actions. Our objective was to develop an index for soil quality using a minimum data set of physical, chemical, and biologica indicators to assess alternative poultry litter management practices. Multivariate statistical techniques were used for data set and index development. Indices were created for two research sites that differed primarily by soil type and climatic regime. Management treatments included land application of fresh or composted poultry litter. Results from routine biogeochemical analyses showed highly significant differences but their usefulness for guiding management decisions was limited without further synthesis and elimination of redundant information. The resultant indices appear to be effective monitors of sustainable management. Using a common framework allows transferable indices to be tailored for local conditions. Index results can also be incorporated into a larger decision-making framework with broad implications for guiding agricultural and animal waste management practices.