Progress 10/01/05 to 09/30/07
Outputs
The objectives were (1) Determine the sensitivity of the hazard different herbicides pose to groundwater quality as calculated with the Pesticide Economic and Environmental Tradeoffs (PEET) decision-support system as a result of differences in soil properties, irrigation management, weather patterns, and herbicide properties. (2) Determine the sensitivity of the ranking of different herbicides for selected crops with regard to the risk they pose to groundwater quality (as calculated in PEET) as a result of differences in soil properties, irrigation management, weather patterns, and herbicide properties. (3) Determine the sensitivity of economic return (as calculated in PEET) for different herbicide treatments to changes in weed population and density, market price of crop, herbicide efficacy, and yield potential. (4) Determine the sensitivity of quantity of ammonia lost to the atmosphere following the application of swine effluent on bare and cropped soil surfaces to soil
and effluent properties. (5) Determine sensitivity of probability of burning, vegetative regrowth, and grazing for sites receiving controlled patch burn to the size and distribution of the areas burned and to stocking rate. (6) Publish the results of these analyses in forms appropriate for model users and other scientists. Objectives 1 and 2 have been completed for peanuts in Caddo county Oklahoma. Results of that analysis were presented at the World Congress of Soil Science. This analysis revealed that degradation halflife, organic carbon, organic carbon partition coefficient, field capacity, and bulk density had relative sensitivities greater than 1 in absolute value. That is, the relative uncertainty in the groundwater hazard is greater than the relative uncertainty in each of these parameters. Only the permanent wilting point had a relative sensitivity less than 1 in absolute value. When the uncertainty in these parameters is considered, the uncertainty in groundwater hazard is
greatest for degradation halflife, followed by organic carbon partition coefficient, organic carbon, bulk density, field capacity and wilting point. Overall uncertainties were commonly greater than 0.5 due only to uncertainty in future daily weather at the site when the groundwater hazard was greater than 1.0. This represents a large uncertainty in groundwater hazard and can result in substantial changes in the treatment rankings. The PEET user should be aware of this when interpreting the results of the decision-support system. To facilitate this, the PEET software has been modified to display error bars around the calculated groundwater hazard values. Work on objective 3 is underway. This analysis is more complex due to the increased number of parameters entering into the calculation. These results and the changes made in the decision support system will enable the decision-maker to make more informed decisions. They also point out the need for such analyses whenever models are
used. It also points out the need for considering multiple weather realizations for a single site when attempting to predict transport and fate of chemicals in soils.
Impacts
We must evaluate the reliability of the decision support system for the decisions of interest. By analyzing the models used and the uncertainty in imput paramenters we can assess the reliability of the predictions and the ultimate decision proposed. We must then convey this informatin to the user in a meaningful way so an informed decision can be made.
Publications
- Nofziger, D.L. 2006. Sensitivity of Decisions Based on the Pesticide Economic and Environmental Tradeoffs (PEET) Decision-Support System to Uncertain Input Parameters. World Congress of Soil Science. Philadelphia, PA.
- Nofziger, D.L. and H. Zhang. 2006. Nutrient Blending Software. http://soilphysics.okstate.edu/software/NutrientBlending
- Katsalirou, Eirini, Shiping Deng, and David L. Nofziger. 2006. Effects of Grazing and Cultivation on Activities of Enzymes Involved in Carbon and Nitrogen Cycles. Soil Science Society of America International Meetings, Indianapolis, IN.
- Katsalirou, Eirini, Shiping Deng, and David L. Nofziger. 2006. Soil Management Induced Changes in Active Phosphorus Pools and Activities of Phosphatases in Mixed Prairie Ecosystems. Soil Science Society of America International Meetings, Indianapolis, IN.
- Katsalirou, Eirini, Shiping Deng, and David L. Nofziger. 2006. Spatial Variability of Microbial Properties in Prairie Soils. World Congress of Soil Science. Philadelphia, PA.
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Progress 10/01/05 to 09/30/06
Outputs
The objectives of this project are (1)Determine the sensitivity of the hazard different herbicides pose to groundwater quality as calculated with the Pesticide Economic and Environmental Tradeoffs(PEET) decision-support system as a result of differences in soil properties, irrigation management,weather patterns,and herbicide properties.(2) Determine the sensitivity of the ranking of different herbicides for selected crops with regard to the risk they pose to groundwater quality (as calculated in PEET) as a result of differences in soil properties,irrigation management, weather patterns, and herbicide properties.(3)Determine the sensitivity of economic return (as calculated in PEET) for different herbicide treatments to changes in weed population and density, market price of crop, herbicide efficacy, and yield potential.(4)Determine the sensitivity of quantity of ammonia lost to the atmosphere following the application of swine effluent on bare and cropped soil
surfaces to soil and effluent properties.(5)Determine sensitivity of probability of burning, vegetative regrowth, and grazing for sites receiving controlled patch burn to the size and distribution of the areas burned and to stocking rate.(6)Publish the results of these analyses in forms appropriate for model users and other scientists. Objectives 1 and 2 have been completed for peanuts in Caddo county Oklahoma. Results of that analysis were presented at the World Congress of Soil Science. This analysis revealed that degradation halflife, organic carbon,organic carbon partition coefficient, field capacity, and bulk density had relative sensitivities greater than 1 in absolute value. That is, the relative uncertainty in the groundwater hazard is greater than the relative uncertainty in each of these parameters. Only the permanent wilting point had a relative sensitivity less than 1 in absolute value. When the uncertainty in these parameters is considered, the uncertainty in groundwater
hazard is greatest for degradation halflife, followed by organic carbon partition coefficient, organic carbon, bulk density, field capacity and wilting point. Overall uncertainties were commonly greater than 0.5 due only to uncertainty in future daily weather at the site when the groundwater hazard was greater than 1.0. This represents a large uncertainty in groundwater hazard (even when all other parameters are known precisely) and can result in substantial changes in the treatment rankings. The PEET user should be aware of this when interpreting the results of the decision-support system. To facilitate this, the PEET software has been modified to display error bars around the calculated groundwater hazard values. Work on objective 3 is underway. This analysis is more complex due to the increased number of parameters entering into the calculation. These results and the changes made in the decision support system will enable the decision-maker to make more informed decisions. They
also point out the need for such analyses whenever models are used. It also points out the need for considering multiple weather realizations for a single site when attempting to predict transport and fate of chemicals in soils.
Impacts
We must evaluate the reliability of the decision support system for the decisions of interest. By analyzing the models used and the uncertainty in imput paramenters we can assess the reliability of the predictions and the ultimate decision proposed. We must then convey this informatin to the user in a meaningful way so an informed decision can be made.
Publications
- Nofziger, D.L. 2006. Sensitivity of Decisions Based on the Pesticide Economic and Environmental Tradeoffs (PEET) Decision-Support System to Uncertain Input Parameters. World Congress of Soil Science. Philadelphia, PA.
- Nofziger, D.L. and H. Zhang. 2006. Nutrient Blending Software. http://soilphysics.okstate.edu/software/NutrientBlending.
- Katsalirou, Eirini, Shiping Deng, and David L. Nofziger. 2006. Effects of Grazing and Cultivation on Activities of Enzymes Involved in Carbon and Nitrogen Cycles. Soil Science Society of America International Meetings, Indianapolis, IN.
- Katsalirou, Eirini, Shiping Deng, and David L. Nofziger. 2006. Soil Management Induced Changes in Active Phosphorus Pools and Activities of Phosphatases in Mixed Prairie Ecosystems. Soil Science Society of America International Meetings, Indianapolis, IN.
- Katsalirou, Eirini, Shiping Deng, and David L. Nofziger. 2006. Spatial Variability of Microbial Properties in Prairie Soils. World Congress of Soil Science. Philadelphia, PA
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Progress 10/01/04 to 09/30/05
Outputs
The objectives of this project are to (1) determine the sensitivity of the decisions of interest to simplifications in decision-support systems and to uncertainty and natural variability in input parameters of those systems, (2) develop effective methods of conveying this sensitivity and uncertainty to end-users, and (3) incorporate additional processes and new understanding into current and new decision-support systems. In the past 12 months we have focused on the Pesticide Economic and Environmental Tradeoffs (PEET) decision-support system. The latest version incorporates real-time simulation of groundwater hazards for the specific management practices specified by the user. This permits the system to model actual farmer practices better and greatly reduces the effort required of scientists implementing PEET for a new crop or a new area. We also completed a comprehensive database management package to assist scientists develop PEET in new crops and new areas. We
have also conducted a sensitivity analysis of the decision-support system. This provides insight into uncertainty in predicted economic return and groundwater hazard resulting from uncertainty (or errors) in user inputs and uncertainty in soil, chemical and environmental variables needed in the model. This information will be shared with users and developers to aid in interpreting the model output. It also identifies the parameters that have the largest impact upon the output and ultimate decisions based on the software.
Impacts
We must evaluate the reliability of the decision support system for the decisions of interest. By analyzing the models used and the uncertainty in imput paramenters we can assess the reliability of the predictions and the ultimate decision proposed. We must then convey this informatin to the user in a meaningful way so an informed decision can be made.
Publications
- Nofziger, D.L. and Jinquan Wu. 2005. PEET Database Management. http://soilphysics.okstate.edu/software/PeetRealTime/PEETDBManager.pd f. 32 pages.
- Katsalirou, Irene, Shiping Deng, D.L. Nofziger. 2005. Response of microbial community to management systems in prairie soils. Soil Science Society of America Abstracts. Paper 275-11.
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Progress 10/01/03 to 09/30/04
Outputs
The objectives of this project are to (1)determine the sensitivity of the decisions of interest to simplifications in decision-support systems and to uncertainty and natural variability in input parameters of those systems, (2)develop effective methods of conveying this sensitivity and uncertainty to end-users, and (3)incorporate additional processes and new understanding into current and new decision-support systems. In the past 12 months we have created a decision-support system for managing the application of swine effluent based on the deterministic model for predicting ammonia volatilization from surface applied swine effluent developed and tested in the past two years. That software is now completed and available. We have also completed a major revision of the popular Chemical Movement in Layered Soils (CMLS) software incorporating dramatically improved graphical user interface and graphics capability, improved capability for Monte Carlo simulations, and
portability across a wide variety of computer platforms and operating systems. We have also rewritten the Pesticide Economic and Environmental Tradeoffs (PEET) decision-support system incorporating real-time simulation of groundwater hazards for the specific management practices specified by the user. Database management software is underdevelopment for scientists interested in using PEET in new crops and new geographical areas. A workshop is scheduled for 2005 to educate scientists interested in utilizing PEET in their areas on the data requirements and use of the software.
Impacts
We must evaluate the reliability of the decision support system for the decisions of interest. By analyzing the models used and the uncertainty in imput paramenters we can assess the reliability of the predictions and the ultimate decision proposed. We must then convey this informatin to the user in a meaningful way so an informed decision can be made.
Publications
- No publications reported this period
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Progress 10/01/02 to 09/30/03
Outputs
The objectives of this project are to (1) determine the sensitivity of the decisions of interest to simplifications in decision-support systems and to uncertainty and natural variability in input parameters of those systems, (2) develop effective methods of conveying this sensitivity and uncertainty to end-users, and (3) incorporate additional processes and new understanding into current and new decision-support systems. In the past 12 months we have created a decision-support system for managing the application of swine effluent based on the deterministic model for predicting ammonia volatilization from surface applied swine effluent developed and tested in the past two years. The decision-support system incorporates simplified weather input parameters that are generally available to farmers and decision-makers. The selection of the final required parameters was based on detailed sensitivity analysis of the deterministic model. Errors introduced by the simplified
weather were less than 5% of the total ammonia volatilized during the first 7 days after application in 85% of the scenarios tested. Due to extensive computing time, the decision-support system incorporates solutions for many combinations of input parameters and uses linear interpolation to provide the user with results for their specified inputs. The interpolation errors are generally less than 5% also.
Impacts
We must evaluate the reliability of the decision support system for the decisions of interest. By analyzing the models used and the uncertainty in imput paramenters we can assess the reliability of the predictions and the ultimate decision proposed. We must then convey this informatin to the user in a meaningful way so an informed decision can be made.
Publications
- Wu, J., D.L. Nofziger, J.G. Warren, and J.A. Hattey. 2003. Modeling ammonia volatilization from surface applied swine effluent. Soil Sci. Soc. America J. 67(1): 1-11.
- Wu, J., D.L. Nofziger, J.G. Warren, and J.A. Hattey. 2003. Estimating ammonia volatilization from swine-effluent droplets in sprinkler irrigation. Soil Sci. Soc. America J. 67 (5).
- Nofziger, D.L., J. Wu, A.G. Hornsby, H.D. Scott, and P.S.C. Rao. 2003. Aquifer Vulnerability Assessment: A Framework for Teaching Soil Physics and More! Agronomy Abstracts.
- Wu, J., and D.L. Nofziger. 2003. Nutrient Value of Swine Effluent Decision Support System. Agronomy Abstracts.
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Progress 10/01/01 to 09/30/02
Outputs
The objectives of this project are to (1) determine the sensitivity of the decisions of interest to simplifications in decision-support systems and to uncertainty and natural variability in input parameters of those systems, (2) develop effective methods of conveying this sensitivity and uncertainty to end-users, and (3) incorporate additional processes and new understanding into current and new decision-support systems. In the past 12 months we have expanded the deterministic model for predicting ammonia volatilization from surface applied swine effluent to include application by sprinkler irrigation. Results from both experiments and the numerical model indicate that additional ammonia volatilization due to sprinkling are very small and are primarily limited to the actual drift of the droplets from the target area. Thus they can be estimated using methods of estimating irrigation water drift. Both these models have been reviewed by peers and are being published. The
rewritten CHEMFLO model and documentation have also been reviewed and is being published by U.S. EPA. The Pesticide Economic and Environmental Tradeoffs decision support system was expanded for peanuts and cotton in OK and made available to users. Twelve other models of water, chemical, and heat transfer and chemical degradation that enable the users to visualize the sensitivity of various output parameters to changes in model inputs have been tested by new users. All of the software is available on the Internet at http://soilphysics.okstate.edu/software.
Impacts
(N/A)
Publications
- Nofziger, D.L. and Jinquan Wu. 2003. CHEMFLO-2000 Interactive Software for SImulating Water and Chemical Movement in Unsaturated Soils. In Press. U.S.E.P.A.
- Wu, J., D.L. Nofziger, J.G. Warren, and J.A. Hattey. 2003. Modeling ammonia volatilization from surface-applied swine effluent. Soil Sci. Soc. Am. J. 67:1-11.
- Wu, J. and D.L. Nofziger. 2002. Sensitivity analysis of ammonia volatilization model to its input parameters. Soil Science Society of America Abstracts.
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Progress 10/01/00 to 09/30/01
Outputs
The objectives of this project are to (1) determine the sensitivity of the decisions of interest to simplifications in decision-support systems and to uncertainty and natural variability in input parameters of those systems, (2) develop effective methods of conveying this sensitivity and uncertainty to endures, and (3) incorporate additional processes and new understanding into current and new decision-support systems. Work in the past 12 months includes the expansion of our deterministic model for predicting ammonia volatilization from surface applied swine effluent to include application by sprinkler irrigation. Model predictions and experimental assessment indicates that application by sprinkler increases losses by less than 10% over application by flooding except at edges of the field where the effluent applied may drift totally off of the target field. CHEMFLO-2000 was developed and delivered to the U.S.E.P.A. It is currently under review and will be distributed
and supported by them. The Pesticide Economic and Environmental Tradeoffs model has been revised and implemented for cotton and peanuts in Oklahoma. This model assists decision makers in selecting appropriate pesticides after considering both economic and environmental consequences of available treatments. If the weed populations are not sufficiently high, the best option may be no herbicide. The CMLS model is being revised and expanded for use in Brazil.
Impacts
(N/A)
Publications
- Patton, J.J., D. L. Nofziger, and J.A. Hattey. 2001. Evaluation of Computer Software. American Society of Agronomy, Oct.21-25, 2001. p186.
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Progress 10/01/99 to 09/30/00
Outputs
The objectives of this project are to (1) determine the sensitivity of the decisions of interest to simplifications in decision-support systems and to uncertainty and natural variability in input parameters of those systems, (2) develop effective methods of conveying this sensitivity and uncertainty to end-users, and (3) incorporate additional processes and new understanding into current and new decision-support systems. Work in the past 12 months has focused on the development and evaluation of a new deterministic model for predicting ammonia volatilization from surface applied swine effluent and an analysis of the sensitivity of this system to soil, chemical, and atmospheric conditions. The model does an excellent job predicting volatilization under the conditions tested. Work is underway to extend the testing to new conditions. Volatilization is not particularly sensitive to soil properties but is quite sensitive to temperature, wind velocity, and the pH of the
effluent. New software was developed for the CHEMFLO model and for other models that enables the user to visualize the sensitivity of various output parameters to changes in model inputs. That software is usable on the Internet.
Impacts
(N/A)
Publications
- Nofziger, D.L., H.D. Scott, and T.H. Udouj. 2000. Relationships between soil properties and chemical transport in landscapes of the southeastern United States. pp 368-384. In H.Don Scott, (ed) Water and Chemical Transport in Soils of the Southeastern United States. Special Report 197. University of Arkansas, Fayetteville, Arkansas. 386 pages.
- Wu, Jinquan and D.L. Nofziger. 2000. Examples of water and chemical transport in the soils of the southern region MLRA 78: Central rolling red plains. pp 110-128. In H.Don Scott, (ed) Water and Chemical Transport in Soils of the Southeastern United States. Special Report 197. University of Arkansas, Fayetteville, Arkansas. 386 pages.
- Nofziger, D.L., and Jinquan Wu. 2000. Soil Physics Teaching Tools: Steady-State Water Movement in Soils. J. of Natural Resources and Life Sciences Education. (Accepted, In Press). Wu, J., D.L. Nofziger, J.G. Warren, and J.A. Hattey. 2000. Modeling ammonia volatilization from surface-applied swine effluent. Agronomy Abstracts p.203.
- Zhang, H. and D.L. Nofziger. 2000. Decision support system fot plant nutrient management. Agronomy Abstracts p. 416.
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