1. Mark Twain Lake/Salt River CEAP – CSWQRU Columbia, MO Overview of the Mark Twain Lake/ Salt River Conservation Effects Assessment Project (CEAP) Contributing Scientists: Robert N. Lerch Newell R. Kitchen Kenneth A. Sudduth E. Eugene Alberts E. John Sadler William W. Donald John W. Hummel Robert J. Kremer Chung-Ho Lin D. Brenton Myers Raymond E. Massey Harlan L. Palm Gab-Sue Jang Contributing Scientists: Robert N. Lerch Newell R. Kitchen Kenneth A. Sudduth E. Eugene Alberts E. John Sadler William W. Donald John W. Hummel Robert J. Kremer Chung-Ho Lin D. Brenton Myers Raymond E. Massey Harlan L. Palm Gab-Sue Jang

2. Mark Twain Lake/Salt River CEAP – CSWQRU Columbia, MO National CEAP effort. National CEAP effort. Mark Twain Lake/ Salt River CEAP. Mark Twain Lake/ Salt River CEAP. Water quality research projects in support of CEAP Water quality research projects in support of CEAP Development and Evaluation of BMPs for Improved Watershed Management. Development and Evaluation of BMPs for Improved Watershed Management. Topics

3. Mark Twain Lake/Salt River CEAP – CSWQRU Columbia, MO The USDA Conservation Effects Assessment Project (CEAP)  A Cooperative Effort to Assess Environmental Effects and Benefits from Conservation Programs

4. Mark Twain Lake/Salt River CEAP – CSWQRU Columbia, MO  The NRCS-led national assessment provides estimates of conservation benefits at the national scale.  The ARS watershed assessment studies provide for more detailed information on conservation effects/benefits in selected benchmark watersheds. CEAP has Two Major Components and Reporting Scales

5. Mark Twain Lake/Salt River CEAP – CSWQRU Columbia, MO 12 ARS Benchmark Watershed Assessment Studies S. Fork Iowa River Walnut Creek Mark Twain Reservoir U. Washita River U. Leon River Town Brook St Joseph River U. Big Walnut Creek Yalobusha River Little River Goodwin Creek Beasley Lake

6. Mark Twain Lake/Salt River CEAP – CSWQRU Columbia, MO Mark Twain Lake/ Salt River CEAP Project Project Objectives Establish a comprehensive monitoring network within the Salt River basin Establish a comprehensive monitoring network within the Salt River basin Validate and improve watershed models to better assess the impact of field- and watershed-scale management practices on surface water quality. Development and evaluation of BMPs to reduce herbicide, nutrient, and sediment transport in surface runoff. Salt River Basin

7. Mark Twain Lake/Salt River CEAP – CSWQRU Columbia, MO Mark Twain Lake/ Salt River Basin Three 8-digit Hydrologic Units Three 8-digit Hydrologic Units Nine 11-digit Hydrologic Units Nine 11-digit Hydrologic Units ~2,500 sq miles in area ~2,500 sq miles in area Mark Twain Lake is major public water supply in the region Mark Twain Lake is major public water supply in the region Serves ~42,000 people Serves ~42,000 people EPA 303(d) list for Atrazine until 2003 EPA 303(d) list for Atrazine until 2003 Claypan soils Claypan soils High runoff potential High runoff potential Surface water quality a major concern Surface water quality a major concern Extensive USGS hydrologic monitoring network already in-place Extensive USGS hydrologic monitoring network already in-place

8. Mark Twain Lake/Salt River CEAP – CSWQRU Columbia, MO Basin-Scale Monitoring 13 Monitoring Sites Automated samplers for runoff events 2 grab samples per month 9 existing gauged sites Rating curves to be developed at 3 sites Mass balance for Mark Twain Lake Identify 11 digit watersheds contributing highest loads to the lake Identify watershed specific problems Measurements: Discharge Rainfall Herbicides (atrazine, acetochlor, metolachlor, metribuzin, selected atrazine metabolites) Nutrients (total and dissolved N and P) Sediment

9. Mark Twain Lake/Salt River CEAP – CSWQRU Columbia, MO Nested Watershed Monitoring Long Branch Watershed Evaluate scale dependence of contaminant transport. Perform model calibrations and validations from sub-watersheds to whole watershed scales.

10. Mark Twain Lake/Salt River CEAP – CSWQRU Columbia, MO Goodwater Creek Watershed Surface water hydrology Surface water hydrology ~35-yr record ~35-yr record Sediment Sediment Weather Weather Water table depth Water table depth Water quality Water quality ~15-yr record ~15-yr record Nutrients Nutrients Pesticides Pesticides Surface and Ground water Surface and Ground water Initial SWAT model calibration is based on this site Initial SWAT model calibration is based on this site ▲Weirs ● Rain gauges   Weather station

11. Mark Twain Lake/Salt River CEAP – CSWQRU Columbia, MO Key Questions Will we see differences in water quality at the watershed scale that can be attributed to conservation practices? Will we see differences in water quality at the watershed scale that can be attributed to conservation practices? Yes, but only if sufficient implementation has occurred. Yes, but only if sufficient implementation has occurred. What if past implementation of conservation practices is insufficient to affect water quality at the watershed- scale? What if past implementation of conservation practices is insufficient to affect water quality at the watershed- scale?

12. Mark Twain Lake/Salt River CEAP – CSWQRU Columbia, MO Expected Outcomes Assess water quality differences at the watershed-scale. Assess water quality differences at the watershed-scale. Contaminant transport normalized to watershed area or area of specific crop types (e.g. kg atrazine/ km 2 ). Contaminant transport normalized to watershed area or area of specific crop types (e.g. kg atrazine/ km 2 ). Loads as a percent of applied mass in the watershed. Loads as a percent of applied mass in the watershed. SWAT Model will be used to determine the most hydrologically vulnerable areas within watersheds (i.e., areas contributing most to contaminant transport). SWAT Model will be used to determine the most hydrologically vulnerable areas within watersheds (i.e., areas contributing most to contaminant transport). Field verification of the model needed. Field verification of the model needed. Develop ability to model BMP impacts on water quality. Develop ability to model BMP impacts on water quality. Develop site evaluation guidelines for targeted implementation of conservation practices. Develop site evaluation guidelines for targeted implementation of conservation practices.

13. Project Status Negotiated a cooperative agreement with Missouri Corn Growers Association to conduct basin-scale monitoring Negotiated a cooperative agreement with Missouri Corn Growers Association to conduct basin-scale monitoring Implemented basin-scale monitoring in Spring 2005 Implemented basin-scale monitoring in Spring 2005 12 sites installed with autosamplers and area/velocity or depth probes 12 sites installed with autosamplers and area/velocity or depth probes Rating curve work to be conducted for nested watersheds Rating curve work to be conducted for nested watersheds Modeling Modeling Calibrated SWAT to Goodwater Creek discharge data at annual and monthly time scales; daily discharge more challenging Calibrated SWAT to Goodwater Creek discharge data at annual and monthly time scales; daily discharge more challenging Spatial and temporal delineation of crop type to improve land-use input data Spatial and temporal delineation of crop type to improve land-use input data FAPRI was awarded CSREES proposal in support of our CEAP FAPRI was awarded CSREES proposal in support of our CEAP USDA-FSA has provided locations of the conservation practices within the Salt River USDA-FSA has provided locations of the conservation practices within the Salt River

14. Mark Twain Lake/Salt River CEAP – CSWQRU Columbia, MO DEVELOPMENT AND EVALUATION OF BMPs FOR IMPROVED WATERSHED MANAGEMENT Herbicide transport from different cropping systems Herbicide transport from different cropping systems Precision Agriculture System (PAS) implementation Precision Agriculture System (PAS) implementation

15. Mark Twain Lake/Salt River CEAP – CSWQRU Columbia, MO Herbicide Transport from Different Cropping Systems Plot-Scale Research Objectives Objectives Evaluate the effects of corn herbicide application methods and application timing on surface water quality. Evaluate the effects of corn herbicide application methods and application timing on surface water quality. Develop equations to predict herbicide concentrations in surface runoff. Develop equations to predict herbicide concentrations in surface runoff. Herbicides studied – atrazine and metolachlor Herbicides studied – atrazine and metolachlor Cropping Systems Cropping Systems CS1 – mulch-till; corn-soybean rotation; herbicides broadcast and incorporated. CS1 – mulch-till; corn-soybean rotation; herbicides broadcast and incorporated. CS2 – no-till; corn-soybean rotation; herbicides broadcast, not incorporated. CS2 – no-till; corn-soybean rotation; herbicides broadcast, not incorporated. CS5 – no-till; corn-soybean-wheat rotation; herbicides broadcast, not incorporated; adaptive approach used to determine atrazine rates and timing. CS5 – no-till; corn-soybean-wheat rotation; herbicides broadcast, not incorporated; adaptive approach used to determine atrazine rates and timing. Split applications, reduced pre-plant rates, post-only application. Split applications, reduced pre-plant rates, post-only application. Corn phase of the rotation was monitored during the growing season from 1997-2002. Corn phase of the rotation was monitored during the growing season from 1997-2002.

17. Mark Twain Lake/Salt River CEAP – CSWQRU Columbia, MO Runoff and Herbicide Losses † CS1 (Mulch Till; C-S) CS2 (No-Till; C-S) CS5 (No-till; C-S-W) Runoff(mm) 59.7a ‡ 67.3a70.8a Atrazine (g ha -1 ) 24.9b55.0a55.3a Atrazine (% of Applied) 1.62.55.7 Metolachlor (g ha -1 ) 15.0b24.7a8.4 Metolachlor (% of Applied) 1.82.02.0 † Six year averages. ‡ ‡ Means within rows with different letters were significantly different (  = 0.10).

18. Mark Twain Lake/Salt River CEAP – CSWQRU Columbia, MO Herbicide Concentrations AtrazineMetolachlor

19. Mark Twain Lake/Salt River CEAP – CSWQRU Columbia, MO General Model for Predicting Herbicide Transport in Surface Water Where: [C] = Computed atrazine or metolachlor concentration (µg L -1 ) [C] = Computed atrazine or metolachlor concentration (µg L -1 ) R = Herbicide application rates (µg ha -1 ) R = Herbicide application rates (µg ha -1 ) Q = Runoff measured for the events (L ha -1 ) Q = Runoff measured for the events (L ha -1 ) t = Time after herbicide application, days t = Time after herbicide application, days a, k = Coefficients a, k = Coefficients Rearranged to solve for loss (i.e. total mass transported): Rearranged to solve for relative loss:

20. Mark Twain Lake/Salt River CEAP – CSWQRU Columbia, MO Herbicide Transport from Different Cropping Systems Conclusions No-till systems (CS2 and 5) did not reduce total runoff compared to the mulch-till system (CS1). No-till systems (CS2 and 5) did not reduce total runoff compared to the mulch-till system (CS1). Herbicide loss was generally higher for no-till than mulch-till cropping systems. Herbicide loss was generally higher for no-till than mulch-till cropping systems. A generalized model for estimating herbicide concentration was developed based on the observed exponential decrease in concentration combined with flow and application rate. A generalized model for estimating herbicide concentration was developed based on the observed exponential decrease in concentration combined with flow and application rate. A key management challenge for claypan soils is development of a cropping system that both minimizes soil erosion and reduces herbicide loss to surface runoff. A key management challenge for claypan soils is development of a cropping system that both minimizes soil erosion and reduces herbicide loss to surface runoff.

21. Implementation of a Precision Agricultural System OBJECTIVE: From a 14-yr history of water and soil quality and spatially-variable crop and soil information, to develop and assess a precision agriculture system that will improve farming profitability and better protect soil and water resources when compared to past management practice.

22. Mark Twain Lake/Salt River CEAP – CSWQRU Columbia, MO Field 1 Research Site 36 ha field established for research in 1990 Cropping System (1991-2004) CS1 – mulch-till; corn-soybean rotation; herbicides broadcast and incorporated.

23. Mark Twain Lake/Salt River CEAP – CSWQRU Columbia, MO 200 Years of Erosion The spatial variability in soil loss over the last 200 years controls the soil quality, water quality, and crop productivity patterns currently observed within this field.

24. A B C D E Total Residual N (kg/ha) 520 A B C D E Decade Total Nitrogen Fertilizer Left on the Field (N fertilizer – Grain N)

25. Mark Twain Lake/Salt River CEAP – CSWQRU Columbia, MO Atrazine Persistence

26. Mark Twain Lake/Salt River CEAP – CSWQRU Columbia, MO Spatial Variability in Average Crop Profit (1991-2004)

27. Mark Twain Lake/Salt River CEAP – CSWQRU Columbia, MO Priorities Identified for the Precision Agriculture System Production (profitability) Surface Water Quality Soil Quality (sustainability) Ground Water Quality 1.Reduce costs 2.Achieve stable yield 3.Improve water use efficiency 1.Reduce sediment loss 2.Reduce herbicide loss 3.Reduce nutrient loss 1.Greatly reduce topsoil loss 2.Improve soil structure to enhance infiltration 3.Build organic matter 1.Decrease nitrate leaching

28. Mark Twain Lake/Salt River CEAP – CSWQRU Columbia, MO Whole Field: no-till grade to remove ponding problems variable rate P, K, and lime variable rate N for wheat and corn PAS Management Approach A A Area A. 2-year rotation of wheat- cover crop hay-soybean. Area A. 2-year rotation of wheat- cover crop hay-soybean. no crop during droughty period no crop during droughty period no soil active herbicides no soil active herbicides cover crop during high erosion times cover crop during high erosion times perennial crops reintroduced perennial crops reintroduced B B Area B. Same as A but with grass hedges in the channel C C Area C. 2-year rotation of corn- soybean

29. Mark Twain Lake/Salt River CEAP – CSWQRU Columbia, MO Summary CEAP will facilitate: CEAP will facilitate: Water quality assessment at the large watershed scale. Water quality assessment at the large watershed scale. Modeling to: Modeling to: Identify hydrologically vulnerable areas within watersheds. Identify hydrologically vulnerable areas within watersheds. Assess water quality impacts of BMPs. Assess water quality impacts of BMPs. Integration of research over multiple scales. Integration of research over multiple scales. Develop site evaluation guidelines for targeted implementation of conservation practices. Develop site evaluation guidelines for targeted implementation of conservation practices.

30. Mark Twain Lake/Salt River CEAP – CSWQRU Columbia, MO Project Partners Missouri Corn Growers Association Missouri Corn Growers Association USDA-NRCS USDA-NRCS University of Missouri- Columbia (UMC) Water Quality Extension University of Missouri- Columbia (UMC) Water Quality Extension UMC School of Natural Resources UMC School of Natural Resources Food & Agric. Policy Research Institute (FAPRI) Food & Agric. Policy Research Institute (FAPRI) MFA, Inc. Cooperative MFA, Inc. Cooperative Clarence Cannon Wholesale Water Commission Clarence Cannon Wholesale Water Commission