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Posted 31 January 2017. PMN Crop News.

The 4Rs and Illinois NLRS

4Rs – Nutrient management and the 4 Rs (right source, rate, time and place)

Source: Article.

By Terry Wyciskalla

Bloomington, Illinois (January 18, 2017)--Nitrogen and P are our two main concerns when addressing impairments to water quality. We have a Federal Drinking Water Standard that allows a maximum of 10 ppm nitrate (N). This nitrate must be removed by the municipal water treatment facilities. Hence, the problems we are seeing in Iowa, Lake Erie and the Chesapeake Bay area.


When it comes to P it is a little more difficult and different rules, regulations and guidelines apply to industry, agriculture, livestock producers and municipalities. Be that as it may, when it comes to P a much smaller quantity of P is needed to cause an algal bloom and water quality degradation.

The 4Rs give us the tools to reduce nutrient losses while still providing enough nutrients for optimal yield. It is all about selecting the right product and applying it at the right rate, time and place—easy yes?

The 4Rs and nutrient loss reduction are very difficult topics to address quickly and easily. There are many opinions, philosophies and science-based studies that drive the nutrient management decisions in Illinois today, not to mention the countless field observations made by the farm producers and CCAs every day. So, we may have to “agree to disagree” on some statements. The goal of Nutrient Management and the 4Rs should be maximizing crop productivity while reducing environmental impacts, thereby showing improvement and support for the ILNLRS. For the Loss Reduction Strategy to be successful, all groups that have a vested interest in production agriculture must be on the same page.

Illinois nutrient loss reduction strategy

I want to give a quick update on the NLRS. In a nutshell, the strategy is set up to reduce total N losses 15% and total P losses 25% by the year 2025. The ultimate goal is to voluntarily reduce both N and P 45% by the year 2035.

Some recent data presented by the Illinois EPA at the Illinois CCA Conference showed about a 10% decrease in nitrate N (not total N) losses to water for the years 2011-2015 as compared to 1980-1996 long-term data. However, this same data set showed about a 17% increase for total P.

Why did the P losses go up while the nitrate N losses went down? There are no clear-cut answers, but one possible contributing factor for the P increase was that water flow rates were up about 2% during this time frame. Other things to consider are: the drought of 2012, nitrate N and P concentrations/trends were variable across the state, and the P species being lost. I mention P species because P losses may come from erosion events where P is attached to soil particles, but dissolved reactive phosphorus (DRP) can be present in water that has very few soil particles in it when it leaves a field.

To learn more about the 4Rs and NLRS and management practices, more information can be found at the following websites:

• The 4R Nutrient Stewardship –

• The Partnership for Ag Resource Management –

• The Illinois Fertilizer and Chemical Association –

• The Illinois Council on Best Management Practices –

• The Fertilizer Institute –

Terry Wyciskalla is an independent crop and soils consultant based out of Nashville, Illinois. He specializes in soil sampling, fertility recommendations, precision ag services and crop problem diagnoses. He serves a 12-county area throughout Illinois. He earned his 4R Nutrient Stewardship certification in 2015 and was part of the 2016 Soy Envoy team.