2023 Biennial Report: Progress toward nutrient loss reduction strategy goals

Algal blooms pose a significant challenge in both in Illinois and the Gulf of Mexico. One of the leading causes of these algal blooms is excess nutrients — primarily nitrogen and phosphorus.

Once these excess nutrients are used up or the season changes, the algae die, and their decomposition uses an enormous amount of oxygen.

This process removes oxygen from the water, which makes the area uninhabitable for marine life and anything that can’t leave will die. These regions of low oxygen are known as hypoxic zones.

Locally, algal blooms can impact the safety of our drinking water and may prompt the closing of recreational sites.

On a broader scale, the Gulf of Mexico experiences adverse impacts on its fishing and tourism industries due to algal blooms and hypoxia.

Recognizing the negative impacts of excess nutrients entering the Gulf of Mexico from upstream sources, the Gulf Hypoxia Task Force tasked the 12 highest contributing states to create a nutrient reduction plan to reduce the amount of nitrogen and phosphorus leaving each state.

Illinois has been identified as one of the highest contributors of nitrogen and phosphorus to the Mississippi River and eventually the Gulf of Mexico.

Because of this, Illinois created a Nutrient Loss Reduction Strategy that was released in July 2015 to address nutrient loads from urban stormwater, point sources and agricultural sources.

A memo from the U.S. Environmental Protection Agency provided a framework that included specific elements that were required to be a part of each state’s nutrient reduction plan.

One of those elements outlined was the production of a biennial report on load reductions and an annual public report on implementation.

Released on Dec. 1, the NLRS Biennial Report provides a status update on the state’s progress toward its outlined nutrient loss reduction goals.

Contained within the 2023 Biennial Report is a table of the statewide riverine flow and nutrient loads that compares the running five-year averages with the baseline date, 1980 to 1996, for nitrate-N load, total phosphorus load and water yield. The most recent five-year average is 2017 to 2021.

The water yield has increased by 23% over the baseline. This increase can partially be attributed to high precipitation years in 2019 and 2020.

There has also been an increase in total phosphorus loads, which are up 35% over the baseline, and nitrate-N loads are up 4.8% over the baseline.

The increase in nitrate-N can partially be explained by the increase in precipitation, which contributes to increased nitrate leaching and subsequent losses from fields.

Addressing agricultural nutrient loss, a list of conservation practices has been created, encompassing in-field, edge-of-field and land-use change practices to reduce nitrate and phosphorus losses to our local waterbodies and downstream.

Conservation practices have been reviewed by the NLRS Agriculture and Water Quality Science Team and approved by the NLRS Policy Working Group before being included as an approved practice, including the recent addition of Water and Sediment Control Basins in the 2023 Biennial Report.

These approved practices are organized into different scenarios to determine the level of implementation needed for Illinois to reach the reduction goals in the agricultural sector.

The Biennial Report updates the implementation status of these practices for each scenario, showcasing local water quality benefits while emphasizing the potential for increased adoption of these conservation practices.

For more information about the progress and updates from the NLRS partners, you can find the 2023 Biennial Report and all previous reports on the Illinois EPA’s NLRS page at go.illinois.edu/NLRS.

Additionally, the Annual NLRS Conference is another opportunity to learn more about Illinois’ progress, which will be held on Jan. 25 in Springfield.

The conference is open to the public and a virtual option is available. The conference registration is now open and available at go.illinois.edu/NLRSconference.

For the fact sheet on the most current approved agricultural conservation practices and nutrient reduction rates, contact your local University of Illinois Extension office or email rccurry@illinois.edu.

Rachel Curry is an agriculture and agribusiness educator at University of Illinois Extension.