Rows of corn

The Threats of Nitrogen Loss

October 07, 2022 2:00 p.m.

Although nitrogen is extremely important to plant growth– it accounts for more than 57% of total fertilizer use–it is also prone to movement and breakdown in soil, leading to nitrogen loss. And what’s wrong with nitrogen loss?

Nitrogen loss leads to chlorosis, or lack of chlorophyll, hindering crop growth. Corn that is grown in nitrogen deficient soil, simply put, can’t make proteins, amino acids, or even its own DNA. There are 3 key ways nitrogen can be lost, vitalization, de-nitrification, and leaching. When added together, that is up to 95% of your nitrogen investment that is at risk of loss. 

30% can be lost to the atmosphere through volatilization

Volatilization is caused by nitrogen sources, such as urea, converting from organic form to ammonia gases that are then released into the atmosphere. Volatilization can account for up to 30% of nitrogen loss, and most commonly occurs in warm moist soils when the urea is on or close to the soil surface. Most nitrogen volatilization occurs in the first 7-14 days after top-dress fertilizer application if moisture is present. Volatilization is reduced when manure and urea fertilizers are applied when soil and air temperatures are cool, or when rain occurs soon after application.

5% - 35% can be lost through biological oxidation, or “de-nitrification”

Denitrification occurs when soil bacteria use nitrate for their respiration in place of oxygen in the air–converting it to nitrogen gas, therefore returning the nitrogen to the atmosphere. This process occurs more rapidly in warm, wet soil that contains an abundance of nitrates. Soil can experience nitrate loss at a rate of 5-35 percent. Denitrification can contribute to the production of greenhouse gases, reacting with the ozone layer and advancing air pollution. Avoiding overwatering, overfertilizing and waterlogging to prevent denitrification. In addition, avoid fertilizer application while the soil is wet.

As much as 30% can be leached, or lost through soil moisture

Leaching, or washing away nitrogen, is the loss of water-soluble plant nutrients from the soil due to rain and irrigation. Nitrogen is highly mobile in the soil; nitrate leaching occurs when the nitrates are washed from the soil in drainage water. Nitrogen is more prone to leaching when soils are wet and pore spaces are saturated. Nitrogen leaching can have a negative impact on water quality–extremely high nitrate levels can lead to toxic water for humans and wildlife, especially newborn babies.  Applying manure and nitrogen fertilizers when crops are actively growing, and using the nitrates for growth and development, will reduce the amount of nitrate in the soil system.

Protecting your fertilizer investment

To protect above ground nitrogen from ammonia volatilization and below ground nitrogen from denitrification and leaching, CHS Agronomy offers its N-Edge portfolio of nitrogen stabilizer products.

Use of N-Edge products can help protect against nitrogen loss is especially critical during these situations:

  • When fertilizer is surface applied, especially to moist soils.
  • Under high crop residue such as reduced or no-till conditions.
  • When warm temperatures, high soil pH, and other weather and field challenges lead to increased nitrogen loss at or near the soil surface.

The latest product in the line-up, N-Edge® Pro is an NBPT and DCD combination nitrogen stabilizer that provides protection against volatility leaching and denitrification in both below and above ground applications.

For more information on N-Edge Pro and the full N-Edge portfolio, visit CHSAgronomy.com or talk to your local CHS Agronomy retailer.

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