Agricultural Nonpoint Source Pollution and Water Quality as a function of Land Management Practices on Four Kansas Farms William W. Spotts Dr. Donald Huggins Dr. Jerry DeNoyelles Dr. Chip Taylor

Introduction Agricultural nonpoint source pollution Best management practices (BMPs) Research: sampling and modeling

Agricultural nonpoint source pollution (NPSP) The USEPA has identified agricultural NPSP as the major source of stream and lake contamination preventing attainment of the water quality goals identified in the Clean Water Act. (1988). What ? Nutrients, pesticides, sediment, pathogens Who? Livestock and cropping systems How ? Diffuse, episodic, weather-driven Where ? KDHE 97% of streams and 80% of lakes Why ? Impacts water quality, aquatic communities, reservoirs

Nonpoint source pollution: Cropland Tillage Field applications

Nonpoint source pollution: Livestock Erosion Fecal coliform N and P loading

Introduction Agricultural nonpoint source pollution Best management practices (BMPs) Research: sampling and modeling

Best Management Practices (BMPs) Methods, measures or practices designed to prevent or reduce pollution Structural controls Source controls Land management How do you measure the “effectiveness” of BMPs?

Introduction Agricultural nonpoint source pollution Best management practices (BMPs) Research: monitoring and modeling

Monitoring: Describe trends, evaluate effectiveness Modeling: Predict pollutant movement Goal: Provide reliable estimates of pollutant loads Application: Total Maximum Daily Load (TMDL)

Project overview Clean Water Farms Project Four farms with different land management practices Runoff and groundwater for 2-5 years SIMPLEX for comparisons

Important Questions What are typical edge of field concentrations relative to different land management practices ? What factors influence agricultural water quality? How do experimental values compare to the expected values? Can changes in land management lower nutrient and herbicide levels in groundwater and field runoff ?

Experimental methods Monitoring program design Sampling efforts SIMPLEX Loading Model

Aspects of a NPSP monitoring program Goals Management Opportunistic Adaptable Participation

Runoff sampling Sigma 800SL Edge of field data First flush runoff

Sampling Shallow Groundwater Lysimeter clusters Depth Transect approach Space

Primary agricultural nonpoint source pollutants Nitrogen Phosphorus Atrazine

Modeling Runoff SIMPLEX Nutrient Loading Version 1.0 Goal: Estimate runoff volumes ArcView GIS –Aerial Photos (DOQQ) –Land Use / Land Cover (site visits) –Drainage area (DRG) –Soils (SSURGO) Inputs: Watershed area, LU/LC and precipitation

DOQQ and LU/LC

Add Topography…

To define the contributing drainage area

LU/LC, Drainage and Soils

Runoff volume and loading estimator

On-farm research of agricultural NPSP

Monitoring crop production systems Land management practices –Stripped-crop rotation –No-till crop production

Bartel farm: Stripped-crop rotation Marion County –French Creek Watershed Concerns –Marion Reservoir –Soil fertility and erosion Sampling: Runoff and groundwater Objectives: Nutrient concentrations relative to the crop rotation

Stripped-crop rotation: Soybeans and wheat

Monitoring program on the Bartel Farm

Field applications of “compost” around the sampling sites were unexpected

Mean* nutrient and herbicide concentrations: Upper site

TN in runoff at the upper sampler

TP in runoff at the upper sampler

Mean* nutrient and herbicide concentrations at the Bartel farm lower site

TN in runoff at the lower sampler Bartel farm Before field applicationsAfter field applications

TP in runoff at the lower sampler Bartel farm After field applicationsBefore field applications

SIMPLEX modeling on the Bartel farm

SIMPLEX Volume calculations Watershed area = 52.2 hectares or 130 Acres

Groundwater on the Bartel farm Two clusters Sampled eleven times Nitrogen Phosphorus Atrazine

Total nitrogen in groundwater at both sites Bartel farm stripped-crop rotation

Total phosphorus in groundwater at both sites Bartel farm stripped-crop rotation

Monitoring crop production systems Land management practices –Stripped-crop rotation –No-till crop production

Peters Farm: No-Till Marion County –South Cottonwood Watershed Concerns –Nutrients and herbicides in runoff –Groundwater contamination –Soil erosion Sampling: Runoff and groundwater Objectives: Monitor trends in nutrient and herbicide concentrations relative to no-till practices.

Residue management at Peters farm

Conventional tillage on neighboring farm

Monitoring program on the Peters farm

Mean* nutrient and herbicide concentrations Peters No-till farm

TN in first flush runoff on the Peters farm Concentration (mg/L) Time (minutes) Sampling Date Jun 22, 98 Sep 20, 98 Oct 2, 98 Oct 11, 98 Nov 10, 98 Jun 16, 99 Aug 1, 99 Nov 22, 99

TP in first flush runoff on the Peters farm Concentration (mg/L) Time (minutes) Sampling Date Jun 22, 98 Sep 20, 98 Oct 2, 98 Oct 11, 98 Nov 10, 98 Jun 16, 99 Aug 1, 99 Nov 22, 99

Atrazine in first flush runoff on the Peters farm Concentration (ug/L) Time (minutes) Sampling Date Jun 22, 98 Sep 20, 98 Oct 2, 98 Oct 11, 98 Jun 16, 99 Aug 1, 99 Kansas statewide average: 1.12 ug/LWatershed average: 1.54 ug/L

SIMPLEX Modeling on the Peters farm

SIMPLEX Volume calculations Watershed area = 79.4 hectares or 196 acres

Groundwater at the Peters farm Sampled 8 times at one location TN < 1.0 mg/L TP < 0.06 mg/L Atrazine < 0.2 ug/L

Monitoring livestock operations Land management practices –Land conversion –Rotational grazing

Townsend farm: Convert cropland to pasture Dickinson County –Deer Creek Watershed Concerns –Erosion of HEL –Nutrients from cropland Sampling: Runoff and groundwater Objectives: Monitor trends in nutrient concentrations relative to the conversion

Continuous wheat alfalfa and fescue

Monitoring program on the Townsend farm

Mean* nutrient and herbicide concentrations in runoff Townsend farm

Total nitrogen in runoff: Concentration (mg/L) Time (minutes) Sampling Date Jul 7, 98 Jul 30, 98 Aug 26, 98 Sep 24, 98 Sep 30, 98 Oct 17, 98 Nov 1, 98 Townsend farm

Concentration (mg/L) Time (minutes) Sampling Date Jul 7, 98 Jul 30, 98 Aug 26, 98 Sep 24, 98 Sep 30, 98 Oct 17, 98 Nov 1, 98 Total phosphorus in runoff: 1998 Townsend farm

SIMPLEX Modeling on the Townsend farm

SIMPLEX Volume calculations Watershed area = 23.1 hectares or 57 acres

Groundwater at the Townsend farm Three clusters sampled eight times at 8 feet Total nitrogen: mg/L Total phosphorus: Two clusters < 0.5 mg/L Upper cluster 0.5 – 1.5 mg/L Atrazine: All clusters < 0.2 ug/L

Monitoring livestock operations Land management practices –Land conversion –Rotational grazing

Marshall County –Lower Black Vermillion Watershed Concerns –Flooding from creek –Soil erosion –Nutrients in runoff Sampling: Runoff and groundwater Objectives: Monitor trends in nutrient concentrations relative to rotational grazing. Howell Farm: Rotational Grazing

Monitoring program on the Howell farm

Mean* nutrient and herbicide concentrations Howell farm

Total Nitrogen Concentration (mg/L) Time (minutes) Sampling Date Jun 9, 98 Sep 28, 98 Nov 1, 98 Jun 22, 99 Jun 20, 00 Jul 17, 00

Total Phosphorus Concentration (mg/L) Time (minutes) Sampling Date Jun 9, 98 Sep 28, 98 Nov 1, 98 Jun 22, 99 Jun 20, 00 Jul 17, 00

SIMPLEX Modeling on the Howell farm

SIMPLEX Volume calculations Watershed area = 33 hectares or 82 acres

Groundwater at the Howell farm Three clusters –Field –Edge –Riparian Sampled 8 times

Review so far Four farms with different land management Runoff and groundwater concentrations SIMPLEX calculates volumes for loading values

Important Questions What are typical edge of field concentrations relative to different land management practices ? What factors influence agricultural water quality? How do experimental values compare to the expected values? Can changes in land management lower nutrient and herbicide levels in groundwater and field runoff ?

TN in groundwater

TP in groundwater

Runoff TN concentrations by land use

Runoff TP concentrations by land use

Important Questions What are typical edge of field concentrations relative to different land management practices ? What factors influence agricultural water quality? How do experimental values compare to the expected values? Can changes in land management lower nutrient and herbicide levels in groundwater and field runoff ?

What affects runoff concentrations Natural levels of N and P (soils) Applications (B and P) Land cover (T and P) Hydrograph

What does runoff hydrograph look like? Is 8-bottle mean a representative concentration?

Important Questions What are typical edge of field concentrations relative to different land management practices ? What factors influence agricultural water quality? How do experimental values compare to the expected values? Can changes in land management lower nutrient and herbicide levels in groundwater and field runoff ?

Experimental TN and TP loading Values

Loading values from literature

Comparing loading values Research Crop production TN: 10.1 and 31.6 TP: 4.1 and 6.8 Livestock Operations TN: TP: Literature Crop production TN: 2.1 to 79.6 TP: 4.1 to 6.8 Livestock Operations TN: 0.26 to 18.6 TP: 0.14 to 4.90

Modeling Issues Loading = Volume X Concentration Scale issues affect volume? Representative concentrations?

Research Conclusions Runoff and groundwater concentration data varied in a wide but acceptable range. Applications, ground cover and weather patterns impact agricultural water quality. Loading values calculated using SIMPLEX and empirical data are similar to literature. However, BMPs are not likely to cause noticeable decreases in nutrient and herbicide concentrations in the short term.

Future study possibilities Identify NPSP “hotspots” Determine field-scale runoff hydrograph

Special Thanks Kansas Rural Center Bartels, Peters, Townsends and Howells KBS: Steve, Jeff, Don, Chip and Jerry YOU