Agricultural pollutant load reductions will be achieved through the implementation of Management Measures at key non-point sources throughout the Oconomowoc River Watershed. In addition to phosphorus load reductions, the Management Measures will provide ancillary benefits to the watershed including the reduction of pollutants such as suspended solids and nitrogen, improvement of soil and water quality in the watershed, and protection of key natural features in the watershed.
Management Measure implementation at each potential program site will be customized to each operation per recommendation of technical experts affiliated with the OWPP. Some examples of agricultural Management Measures are described below:
Cover crops are plants that are typically grown in the fall after the main crop is harvested. Cover crops are meant to grow quickly and establish a substantive root structure near the surface of the soil, thus holding the soil in place and helping to prevent soil erosion. The crop dies in the cold weather, but the root structure remains in the soil to stabilize it during the winter months.
Reduced tillage practices can result in healthier soil and reduced soil loss. Improvements can include implementing no-till or conservation tillage practices (disc till) in lieu of the traditional chisel plow to reduce the magnitude of tilling. Reduced tillage allows organic material to thrive in soil which helps to maintain a healthy aggregation and structure. It also increases the ability for soil to hold water and nutrients while preventing surface sealing and compaction of soil.
Riparian Buffers and Grassed Waterways
Riparian buffers are meant to inhibit solids transport and promote nutrient uptake from runoff originating from agricultural operations before reaching nearby surface water. Riparian buffers are typically effective starting at a minimum width of 75 feet. “Harvestable” buffers are special types of riparian buffers that can be harvested a couple times a year. This gives the buffer economic value to the landowner and also actively removes nutrients taken up by the plant from the area. Grassed Waterways are drainage channels in a field that are planted with grasses to reduce erosion and the transport of pollutants to the ditch line.
Conservation cover is a long-term practice that takes agricultural land out of production for extended periods of time. The permanent vegetative cover serves to accomplish several important conservation goals including the reduction of soil erosion and sedimentation, the improvement of soil and water quality, and the enhancement of wildlife and pollinator habitat. The vegetative cover typically consists of grasses, forbs, shrubs, and legumes to achieve a diverse mix to promote bio-diversity and restore natural habitats.
Wetland restoration consists of taking land in low areas with hydric soils out of production and converting it back into a wetland. Often low-lying land near surface water is marginal for production and is prone to flooding with heavy rains. Wetland restoration promotes biodiverse, natural habitats for plants and animals, provides a natural means of erosion control, and reduces the risk of flood damage. Wetlands also capture sediments, filter pollutants, and improve water quality which enhances the area’s aesthetic and recreational value.
Nutrient Management Plans
The purpose of Nutrient Management Plans is for farmers to have a proactive plan for managing the level of nutrients in their soil for optimum crop yields. The plans also help prevent an excess of nutrients in the soil, which reduces the risk of pollutant runoff associated with soil loss. The goal of the plans is to balance the optimum amount of nutrients required for a particular farming operation taking into account soil type, field slope, crop rotation, and tillage practices.
Barnyard improvements consist of practices that can be implemented in areas of concentrated livestock feeding. These areas typically lack vegetation or well-established root systems because of the high traffic from livestock. Improvements include the installation of terraces, re-grading, multiple animal feed points, and the covering of feed points.