Agriculture Best Management Practices

Science Center Objects

One major objective of the GLRI is to reduce nutrient loads from agricultural watersheds by implementing conservation or other nutrient-reduction practices. These efforts focus on reducing phosphorus runoff from fields. USGS scientists are supporting these efforts by providing data and other information to help managers understand the impacts of practices on nutrient runoff. 

Edge of field monitoring site in Indiana
(Public domain.)

Edge of Field Monitoring

Edge-of-field (EOF) monitoring sites are installed at the edge of agricultural fields, either on the field surface or using subsurface tiles, where runoff can be intercepted and channeled through monitoring equipment before it enters the natural stream system. EOF sites monitor both runoff quantity and quality. For this effort, the USGS uses a nested-basin design where both individual field runoff and larger subbasin streams are monitored. By monitoring at multiple scales, both the immediate effect of a conservation practice on a single field and the cumulative effect on the larger watershed can be evaluated.

The purpose of this effort is to evaluate sources and potential reductions of nutrients and sediments delivered from agricultural areas through implementation of USDA agricultural conservation practices within the Priority Watersheds (Lower Fox River, WI; Saginaw River, MI; Maumee River, OH; and Genesee River, NY). These watersheds were selected because of the high density of agricultural land use and their ecosystem impairments. All Priority Watersheds are associated with designated Areas of Concern, which are waters of significant environmental degradation. This effort will provide relevant information to scientists and participating agencies evaluating the impacts of agricultural conservation practices through a combination of monitoring and modeling at multiple scales.

Nutrient Cycling Field Research
(Public domain.)

Modeling to Predict Benefits of Best Management Practices

Water-quality models are built using land use, soils, elevation, climate, and land-management practice data tailored to each EOF site's farm field basin. With additional on-farm information provided by Natural Resource Conservation Service, these models quantify the potential changes that result from conservation practices and help assess the cumulative effect of multi-farm changes on the water quality of the larger watershed. Since these models represent common Great Lakes agricultural practices, basin-level results are often transferable to other agricultural areas across the Great Lakes basin.

Understanding the Connections Between Soil Health and Water Quality

In collaboration with University of Wisconsin – Green Bay and Purdue University, this effort focuses on both the biological and physical components of soil health.  Study results include the size and diversity of microbial population in the soil, and the effects of added materials and management on their populations, as well as key physical parameters such as water retention, soil structure, and nutrient release.  This effort will provide a better understanding of changes in health of soil using early predictions based on selection of plant materials, planting strategy, and soil management for cover crops. This information can be utilized within a producer’s management plan to ultimately make positive changes in farm soil health.  An approach for the predicting of soil health changes following the implementation of different management programs and the impact on surface runoff will also be developed.