Conservation Farming Relating to Water-Quality and Quantity

Science Center Objects

The U.S. Department of Agriculture Natural Resources Conservations Service and the U.S. Environmental Protection Agency have focused part of the National Water Quality Initiative (NWQI) on the School Branch watershed. The USGS is collaborating, through a Clean Water Act Section 319 grant, with the Indiana Department of Environmental Management to accomplish NWQI nonpoint-source water-pollution assessment activities in the School Branch watershed.

The School Branch watershed, located in Hendricks County Indiana,  has become the focus of a collaborative partnership of federal, state, and local agencies, a university research center, and agricultural producers to understand the effects of conservation cropping practices on water quality and water quantity.

Map of the School Branch watershed in Indiana

Map of the School Branch watershed in Indiana

What  is Conservation Cropping?

Conservation cropping is a combination of best management practices:

  • Zero or no-till management
  • “Continuous” cover crops
  • Precision nutrient and pesticide application
  • Improved soil health, productivity, drought resistance

School Branch Watershed

  • 5,747 acres (9 mi2)

Land Use: 

  • 80% agricultural (corn, soybeans, wheat, pasture, hay)
  • 13% developed (suburban/rural housing, open space)
  • 90% agricultural N of CR 750 N
  • 40% of agricultural land use has been in conservation cropping for 10 years on 2 farms

What data are we collecting?

Stream sampling in the School Branch watershed

Stream sampling at the School Branch site - CR750N

This USGS study provides water-quality and water-quantity information for three surface water sites on School Branch and at nested monitoring wells in the watershed.  One surface water site has a supergage which provides continuous water-quality data for temperature, pH, specific conductance, dissolved oxygen, turbidity, nitrate as nitrogen, and orthophosphate as phosphorus.

Streamflow from 3 gages:

Monitoring wells in the School Branch watershed in Indiana

School Branch monitoring wells

Monitoring Wells:

Continuous water levels and temperature from four wells   








Polar Organic Chemical Integrative Sampler

Polar Organic Chemical Integrative Sampler

Water-Quality Samples:

  • Discrete water-quality samples at three streamgages
  • Develop surrogate models using discrete data and continuous data from supergage
  • Compare instantaneous loads through the watershed
  • Examine relation of streamflow & water quality

Specific Parameters for Discrete Water-Sample Analysis

  • Dissolved ammonia as nitrogen
  • Dissolved ammonia as nitrogen and organic nitrogen
  • Whole water nitrogen
  • Dissolved nitrite as nitrogen
  • Dissolved nitrite plus nitrate as nitrogen
  • Dissolved orthophosphate as phosphorus
  • Whole water phosphorus
  • Suspended sediment 





Supplemental Water Analyses

Along with sampling at the surface-water sites for nutrients and sediment, the USGS will be conducting more intensive sampling during the growing season.  This includes water-quality sampling for nutrients, ions, and isotopes in surface and groundwater, as well as deploying passive samplers for septic systems wastewater indicators in streams.


Algae Invert sampling at DR 750N School Branch site

Algae invert sampling

Additional sample analysis will include:

  • Calcium, dissolved
  • Chloride, dissolved
  • Fluoride, dissolved
  • Iron, dissolved
  • Magnesium, dissolved
  • Manganese, dissolved
  • Potassium, dissolved
  • Dissolved solids
  • Silica, dissolved
  • Sodium, dissolved
  • Sulfate, dissolved
  • 60 wastewater indicator  compounds
  • Hydrogen H2/H1 isotopes
  • Oxygen O18/O16 isotopes
  • Nitrogen N15/N14 isotopes

Biological Assessment

  • Fish and benthic invertebrate community samples
  • Algal biomass
  • Habitat assessment  


Electrofishing at School Branch IN Noble Drive surface water site

Electrofishing at School Branch IN Noble Drive surface water site