Spread across three states and spanning nearly seven million acres, the Western Lake Erie Basin (WLEB) gathers water from farms, fields, towns and cities and delivers it to Lake Erie. Although the smallest of the Great Lakes by water volume, Lake Erie provides drinking water for 14 million people, boasts the most productive fisheries, and is an economic engine for the region.
Since 1995, dissolved phosphorus loading to the Western Lake Erie Basin from monitored tributaries has steadily increased, despite decreasing trends in total phosphorus and sediment loading. However, even with widespread adoption of conservation practices, approximately 800,000 cubic yards of sediment are deposited in the shipping channel for the Port of Toledo, the Great Lakes’ second busiest port. Continued reductions in sediment, total phosphorus, and nitrogen are urgently needed.
While agriculture has a role to play in addressing water quality in the basin, the problem is bigger than agricultural production. The cause of algal blooms in the WLEB is complex; water temperature, lack of agitation, rainfall and runoff from farms and lawns, and legacy phosphorus in the system all contribute to the problem. Even as all sectors of society work to develop a comprehensive solution to this shared problem, it is likely there will still be a lag-time before the benefits of these efforts are measurable at a regional scale.
Effects of Conservation in the Basin
NRCS recently released a new report through its Conservation Effects Assessment Project (CEAP) that evaluates the impacts of voluntary conservation in the WLEB and conservation treatment needs. This report found that farmers are already contributing significant benefits through voluntary conservation activities they have undertaken on their operations and estimates that farmers have implemented at least one conservation practice on 99 percent of cropland acres.
These conservation investments are making headway toward reducing losses of sediment and nutrients from farm fields. As compared with a hypothetical scenario that simulates no conservation practices, the assessment estimates that conservation practices in use in 2012 reduced:
Annual sediment losses by 81 percent (or 9.1million tons per year),
Annual total nitrogen losses by 36 percent (or 40.6million pounds per year), and
annual total phosphorous losses by 75 percent (or11.4 million pounds per year).
Additional Conservation Needs
The CEAP report recognizes that WLEB croplands are diverse in terms of soils, farm fields, farming operations, and management, which creates differences in conservation needs and potential solutions. No single conservation solution will meet the needs of each field and farm. Comprehensive field-scale conservation planning and conservation systems are needed to accommodate different treatment needs within and across farm fields, while maintaining productivity.
Nutrient and erosion control needs vary across cropped fields, requiring management of unique zones or soils within field boundaries. Precision agriculture techniques that involve potential yield effects, zoned or gridded soil testing, and variable fertilizer rates can help achieve additional nitrogen and phosphorus loss reduction. Producers can use these technologies to identify low yielding or highly vulnerable portions of fields that may benefit from more intensive management or alternative uses.
Strategies to Address Water Quality Opportunities
NRCS will work closely with its conservation partners to implement a comprehensive approach to protect and enhance water quality. The four elements of the initiative are:
Avoid Excess Nutrient Application
Control Nutrient and Sediment Movement
Trap Nutrient and Sediment Losses
Manage Hydrological Pathways to Reduce Nutrient and Sediment Losses
Targeting Conservation Solutions at Multiple Scales
One of the key attributes to a landscape-scale approach is for the Agency and conservation partners to use science and technology to target conservation actions where the greatest opportunities exist to address natural resource concerns. This can include targeting actions in geographic regions of a large landscape to the locales in greatest need of conservation or focusing on the most effective system of conservation practices to address water quality concerns.
At the Basin scale, NRCS and partners will be working with farmers to promote systems of conservation practices to address the appropriate risks for sediment and nutrient losses. On the farm and field scale planning and conservation systems will be used to prevent and capture surface losses on at risk soils and farmlands. NRCS will help producers install conservation systems that avoid and manage losses through subsurface pathways.
NRCS will give priority consideration for financial assistance to these highly vulnerable soils, particularly in areas draining directly into Lake Erie tributaries. Precision conservation planning and agriculture management, including GIS gridded soil testing, variable rate nutrient application, drainage water management and new technologies that micro-target areas within a field can be used to accelerate conservation in these areas.