Project Number:
DATCP 2022-2
Funding Year:
Contract Period:
Funding Source:
DATCP
Investigator(s) and affiliations:
Amber M. Radatz, University of Wisconsin–Madison, Division of Extension;
Ellen Albright, University of Wisconsin–Madison, Division of Extension;
Aaron Wunderlin, University of Wisconsin–Madison, Division of Extension.
Abstract:
Background/Need
Nitrate, which is a critical nutrient for agricultural crop production, has also become Wisconsin’s most widespread groundwater contaminant. There is a growing body of research on nitrate leaching dynamics within the Central Sands region of the state, but there is little knowledge of the movement of nitrate beyond the crop rooting zone in other areas of the state. Most research efforts related to nitrogen in agricultural settings have focused on the growing season with an emphasis on nitrogen production inputs and less so, on quantifying the losses below the unsaturated root zone. With elevated nitrate concentrations in groundwater in several areas of the state, there is a need to better understand and
quantify the nitrogen leaching dynamics outside of the Central Sands region of the state. Pepin County, WI is one of these areas of the state where nitrate contamination to groundwater is a concern. Equilibrium tension lysimeters can be used to quantify the timing and magnitude of nitrate leaching below the crop root zone. This information will help stakeholders and agricultural producers to understand nitrogen leaching dynamics below the crop root zone and begin to identify agricultural conservation practices and/or management strategies that can be used to reduce nitrogen leaching.
Objectives
Objective 1: Increase documentation of timing and magnitude of nitrate leaching below the root zone in Pepin County.
Objective 2: Engage farmers in protecting groundwater from nitrate contamination through implementing and assessing the nitrogen reduction capacity of agricultural practices such as cover crops, reduced nitrogen application rates and diverse crop rotations.
Objective 3: Utilize test results from the nearby affected well to demonstrate effects of agricultural management changes. Objective 4: Provide a model for local governments to address agricultural nitrate contribution to groundwater nitrogen management practices with local farmers.