Progress 10/01/12 to 09/30/13
Outputs
Progress Report Objectives (from AD-416): To develop comprehensive experimental data sets for testing and improving manure-borne pathogen fate and transport models suitable for nutrient management planning and environmental risk assessment. Approach (from AD-416): Field experiments will be performed at the OPE3 field site and the Patuxent runoff site to: (a) evaluate the effect of the buffer strip status on its retention efficiency, (b) develop model parameters and evaluate model performance, and (c) evaluate the phosphorus in runoff as a natural indicator of E. coli. The edge-of-the-field conditions will be simulated at the Patuxent site where the manure suspensions will be maniflolded to the simulated vegetated buffer strips with varying soil type, initial soil moisture content, vegetation status, and slope. The rainfall will be simulated to cause runoff that will be collected at the bottom of the strips. Concentrations of E. coli and P will be measured in the runoff transport. Appropriate complementary soil, hydrologic, and microbial measurements will be carried out. The field-scale transport will be studied at the OPE3 site after manure application in accordance with Maryland agronomic rates. E. coli contents will be monitored in manure, in soil, in runoff using automated samplers, in groundwater, and in the first order creek separated from the field with a riparian zone. All experiments will be performed with participation of USDA employees. Cooperator will participate in modeling, data analysis, and publication of results. This research included experiments and data analysis to establish survival and release parameters for E. coli deposited with manure. Rainfall simulation experiments were performed in plots with land-applied bovine manure at different times after application. Samples of runoff, soil, and manure were collected and analyzed. Consecutive E. coli concentrations in runoff were analyzed to evaluate three models of E. coli release kinetics. Preliminary results show that the E. coli concentrations in runoff did not change much during one hour of intensive rainfall. This is a critical observation indicating the need for revision of the exponential release model that has been developed with data on farmyard slurry application, but is currently used with farmyard manures to evaluate manure management policies and practices. We have also continued to populate the unique database DIMEM on inactivation of microorganisms, and compare the temperature dependencies of inactivation rates for E. coli, Salmonella and Enterococci in surface waters used for irrigation and recreation. Dependencies of the inactivation of the three organisms on temperature displayed similar response patterns. However, site-specific variability in the data was observed which illustrates the uncertainty encountered in estimating the risk of microbial contamination in surface waters. This study will be extended to provide additional guidance on the calibration of indicator fate and transport modeling systems that are used to support environmental management decisions regarding the use of surface water sources in agriculture, aquaculture, and recreation.
Impacts
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Progress 10/01/11 to 09/30/12
Outputs
Progress Report Objectives (from AD-416): To develop comprehensive experimental data sets for testing and improving manure-borne pathogen fate and transport models suitable for nutrient management planning and environmental risk assessment. Approach (from AD-416): Field experiments will be performed at the OPE3 field site and the Patuxent runoff site to: (a) evaluate the effect of the buffer strip status on its retention efficiency, (b) develop model parameters and evaluate model performance, and (c) evaluate the phosphorus in runoff as a natural indicator of E. coli. The edge-of-the-field conditions will be simulated at the Patuxent site where the manure suspensions will be maniflolded to the simulated vegetated buffer strips with varying soil type, initial soil moisture content, vegetation status, and slope. The rainfall will be simulated to cause runoff that will be collected at the bottom of the strips. Concentrations of E. coli and P will be measured in the runoff transport. Appropriate complementary soil, hydrologic, and microbial measurements will be carried out. The field-scale transport will be studied at the OPE3 site after manure application in accordance with Maryland agronomic rates. E. coli contents will be monitored in manure, in soil, in runoff using automated samplers, in groundwater, and in the first order creek separated from the field with a riparian zone. All experiments will be performed with participation of USDA employees. Cooperator will participate in modeling, data analysis, and publication of results. The research included experiments and data analysis to establish survival and release parameters for E. coli deposited with manure. Rainfall simulation experiments were performed at plots with land-applied bovine manure on different times after application. Samples of runoff, soil, and manure were collected and analyzed. All experiments were performed with participation of USDA employees. We also acquired data of analogous experiments from New Zealand, Virginia, Nebraska, and Tennessee. We developed the model of temperature effect on E. coli survival in manure and tested the validity of this model with above experimental data. The preliminary results show that the model is valid after the E. coli die- off begins to dominate growth of the organism. More work is needed to understand and predict the initial E. coli growth phase that may increase the E. coli concentration in manure up to two orders of magnitude, and therefore can affect the accuracy of the E. coli load estimates which are commonly used in microbial water quality forecasts for surface waters. Consecutive E. coli concentrations in runoff were analyzed to evaluate three models of E. coli release kinetics. The preliminary results show that the E. coli concentrations in runoff do not change much during one hour of intensive rainfall. This is a critical observation indicating the need in revision of the exponential release model that is currently used to evaluate manure management policies and practices.
Impacts
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Progress 10/01/10 to 09/30/11
Outputs
Progress Report Objectives (from AD-416) To develop comprehensive experimental data sets for testing and improving manure-borne pathogen fate and transport models suitable for nutrient management planning and environmental risk assessment. Approach (from AD-416) Field experiments will be performed at the OPE3 field site and the Patuxent runoff site. to (a) evaluate the effect of the buffer strip status on its retention efficiency, (b) develop model parameters and evaluate model performance, (c) evaluate the phosphorus in runoff as a natural indicator of E. coli. The edge-of-the-field conditions will be simulated at the Patuxent site where the manure suspensions will be maniflolded to the simulated vegetated buffer strips with varying soil type, initial soil moisture content, vegetation status, and slope. The rainfall will be simulated to cause runoff that will be collected at the bottom of the strips. Concentrations of E. coli and P will be measured in the runoff transport. Appropriate complementary soil, hydrologic, and microbial measurements will be carried out. The field-scale transport will be studied at the OPE3 site after manure application in accordance with Maryland agronomic rates. E. coli contents will be monitored in manure, in soil, in runoff using automated samplers, in groundwater, and in the first order creek separated from the field with a riparian zone. All experiments will be performed with participation of USDA employees. Cooperator will participate in modeling, data analysis, and publication of results. Field experiments were performed at the OPE3 field site and the Patuxent runoff site to (a) evaluate the effect of the buffer strip status on its retention efficiency, (b) develop model parameters and evaluate model performance. Appropriate complementary soil, hydrologic, and microbial measurements were carried out. The field-scale transport were be studied at the OPE3 site after manure application in accordance with Maryland agronomic rates. E. coli contents were monitored in manure, in soil, in runoff using automated samplers, in groundwater, and in the first order creek separated from the field with a riparian zone. All experiments were performed with participation of USDA employees. The important result of this work consisted in the demonstration of the need to include the kinetic energy of rain along with the rainfall intensity in the models of bacteria release, transport and retention in vegetated buffer strips and pasturelands. The progress of the work has been monitored by monthly meetings with the UMD counterparts, and weekly group meetings.
Impacts
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Progress 10/01/09 to 09/30/10
Outputs
Progress Report Objectives (from AD-416) To develop comprehensive experimental data sets for testing and improving manure-borne pathogen fate and transport models suitable for nutrient management planning and environmental risk assessment. Approach (from AD-416) Field experiments will be performed at the OPE3 field site and the Patuxent runoff site. to (a) evaluate the effect of the buffer strip status on its retention efficiency, (b) develop model parameters and evaluate model performance, (c) evaluate the phosphorus in runoff as a natural indicator of E. coli. The edge-of-the-field conditions will be simulated at the Patuxent site where the manure suspensions will be maniflolded to the simulated vegetated buffer strips with varying soil type, initial soil moisture content, vegetation status, and slope. The rainfall will be simulated to cause runoff that will be collected at the bottom of the strips. Concentrations of E. coli and P will be measured in the runoff transport. Appropriate complementary soil, hydrologic, and microbial measurements will be carried out. The field-scale transport will be studied at the OPE3 site after manure application in accordance with Maryland agronomic rates. E. coli contents will be monitored in manure, in soil, in runoff using automated samplers, in groundwater, and in the first order creek separated from the field with a riparian zone. All experiments will be performed with participation of USDA employees. Cooperator will participate in modeling, data analysis, and publication of results. Recent studies have shown that stream bottom sediments can harbor large numbers of E. coli. During rainfall events, these bottom sediments are suspended, resulting in high E. coli concentrations in the water. Experiments were conducted to simulate runoff of dilute manure into sediments and the subsequent growth and survival of E. coli strains. A dilute dairy manure slurry containing fresh E. coli was added to sediments with different textures, organic matter contents, and indigenous E. coli concentrations, and incubated in chambers with flowing creek water at 4�C, 14�C, and 24�C. The highest die-off rates were observed in sandy sediments with low organic carbon and low indigenous E. coli concentrations, while the lowest die-off rates were observed in silty sediments with high organic carbon content and high indigenous E. coli concentrations. In another series of experiments, methods of E. coli extraction from sediments were compared. The progress of the work has been monitored by monthly meetings with the UMD counterparts, and weekly group meetings. Results are relevant for research scientists investigating the dynamics of water-borne bacteria and to regulatory agencies tasked with minimizing surface water contamination.
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