Nitrate

What is Nitrate and where does it come from?

Katie Pekarek, Water Quality Extension Educator, University of Nebraska & Crystal Powers, Research and Extension Communications Specialist, Nebraska Water Center

Nitrogen is a valuable fertilizer source that keeps Nebraska growing abundant landscapes and crops. Nitrogen that does not get used by the crop ends up in our streams, lakes and groundwater. Nitrate is the most common form of nitrogen found in water.

Impacts (Health, Economic, and Recreation)

Nitrate in Nebraska waters has economic, recreation, and health impacts for all of our citizens.

  • Farmers recognize the economic and opportunity loss of nitrogen that is not utilized for growing crops.
  • Millions of tax dollars are managed by Natural Resources Districts, Cities, and conservation agencies to prevent and treat nitrate contamination of water annually.
  • Nearly 1 in 5 Public Water Supplies and private wells in Nebraska consistently tests high for nitrate-nitrogen.  This number is growing. (NDEE Groundwater Report, Risk and Cost Assessment of Nitrate Contamination in domestic wells).
  • Nitrate is a significant contributor to the presence of Harmful Algal Blooms (HABs). Public beaches in Nebraska are monitored for HABs and closed if the level gets to high.  
  • Long term exposure of high nitrate levels can harm fish and their habitats as the result of excessive aquatic plant growth, modified pH, and lowered dissolved oxygen levels.
  • Research has long shown that nitrate exposure is a hazard for infants.  Emerging research has demonstrated strong links with high nitrate concentrations in drinking water and lifetime risk of negative birth outcomes, thyroid disease, and certain cancers (Reference). The drinking water standard for nitrate in water is 10 mg/L.

Now is the Time to Use the Nutrients You are Banking in Your Soils

With the recent increase in fertilizer prices, it is more important than ever to use the right amount of fertilizer to maximize the economic returns. Applying too little or too much fertilizer can result in substantial economic loss.

The science behind 50-degree soil and nitrogen application

Does nitrogen becoming nitrate mean we are going to lose it? No, it takes rainfall or snowmelt in the spring that will cause a leaching event, but it does increase the risk of loss. Certainly, there is a balance between making sure we get our manure applied before the soil freezes and applying too early, but hopefully the information above illustrates a bit behind the science of the 50°F and cooling recommendation.

Nebraska Nitrate Working Groups - Summary and Call for Action

Collaborating organizations Aubudon Nebraska

Dietary Strategies to Reduce Nitrogen and Phosphorus Excretion in Feedlot Cattle

Dietary nutrients, specifically nitrogen and phosphorus, are excreted in manure from feedlot cattle. Dietary strategies, including calculated protein supplementation and phase-feeding programs, can be implemented by cattle feeders to decrease nutrient excretion and improve nutritional efficiency of the animal.

Small communities pay high costs for clean water

In Nebraska, 85% of our citizens rely on drinking water pumped from the ground. When a community's public drinking water supply is affected by high nitrate levels that exceed 10 ppm, it can cost hundreds of thousands - even millions - of dollars to fix.

Nitrate in Drinking Water

Historical and current water quality monitoring shows that nitrate is present in groundwater throughout much of Nebraska. It is when results are at or above the 10mg/L Maximum Contaminant Level (MCL) that hazardous health effects become a concern among humans and animals. Nitrate is colorless, odorless, and tasteless and the only way it can be detected in drinking water is through submitting a sample for laboratory testing.  Where Does Nitrate Come From and What is Nitrification?

Nitrate in Nebraska

From increased water bills to closed lakes to tainted drinking water, high nitrate levels are affecting thousands of Nebraskans. Nitrate can’t be seen or smelled, but it is in Nebraska’s groundwater, which is the source of drinking water for much of the state. Nitrate also contaminates surface water such as streams and lakes. 

No-till, Cover Crops, And Planned Grazing Systems Workshop to be held in Norfolk February 12th

If you are interested in learning more about Soil Health, Cover Crops and Nitrogen Management consider attending the No-till cover crops grazing workshop held by the Bazile Groundwater Management Area, Lower Elkhorn Natural Resource District and the NRCS in Norfolk at the Lifelong Learning Center. The workshop will run from 9:00 a.m. to 3:30 p.m. with lunch provided by the Bazile Groundwater Area NRDs.

Why does groundwater nitrate vary so much across Nebraska?

Have you ever wondered why groundwater nitrate maps show so much variation across Nebraska? Or why wells near to your own tested well have such different nitrate levels? The answer has three parts. Nitrate in groundwater varies from place to place because of differences in:

How can nitrogen budgeting estimate nitrate-N loading to groundwater?

Nitrogen (N) budgeting, where accounting principles are applied to measured quantities of individual N sources, is one tool for understanding how long-term fertilizer-N use and irrigation contributes to nitrogen leaching. Here, we explore this tool by going through commonly-used conversions and calculations for N supply and nitrate-N leaching to account for changes in aquifer nitrogen contamination.

Proactive Drinking Water Management for a Unique Water System

The City of Auburn, population 3,000, is located in southeast Nebraska, near the Little Nemaha River, approximately seven miles upstream of its confluence with the Missouri River. The City receives its drinking water from a wellfield located east of the community within an alluvial aquifer along the Little Nemaha River. The wellfield consists of 11 vertical wells averaging 45 to 50 feet below the ground's surface, pumping up to 150 million gallons per year.

Manure Applications Prior to Planting

Spring manure applications may provide environmental and crop production advantages compared to fall manure applications. These benefits include reduced nitrogen leaching, increased crop yields, and higher phosphorus and potassium nutrient soil storage.