Understanding the 3 Types of Nitrogen Loss — and How to Stop Them

“The one thing we always know about nitrogen is that it disappears and does so quite readily,” laughed Tim Laatsch, director of agronomy, North America, for Koch Agronomic Services (KAS). 

The 3 types of nitrogen loss

There are three commonly recognized forms of nitrogen loss:

Volatilization

Volatilization is the loss of ammonia nitrogen to the atmosphere, commonly associated with urea or urea-containing fertilizers such as UAN. This is considered an above-ground loss.

Leaching

Leaching occurs when nitrate moves downward with water through the soil profile. The negatively charged nitrate cannot adhere to the positively charged soil, allowing it to leave with the flowing water. This below-ground loss often happens in coarsely textured soils that are well drained or in artificial tile drainage systems. 

Denitrification 

Denitrification is the other side of below-ground loss, often occurring in finely textured, poorly drained soils. These soils tend to stand waterlogged, during which bacteria in the soil use nitrate to breathe, as they can’t access oxygen. They respire the nitrate as a gas, most commonly nitrous oxide, which is then lost to the atmosphere.

Factors which determine the type of loss

We know that nitrogen is prone to loss, but a complex interaction of factors determines what type of loss any operation will experience. The 4Rs framework of nutrient stewardship can play a vital part in protecting against loss, focused on applying fertility of the right source at the right rate at the right time in the right place. 

Environmental factors play a significant role, including soil type, drainage, organic matter and pH. Higher pH soils are more prone to loss from volatilization and nitrification. Temperature and rainfall overlay all these factors. As temperatures warm up, enzymatic processes speed up, exacerbating nitrogen losses. But water can be more complicated to understand. Water directly impacts below-ground loss but can also play a role in above-ground loss. 

“With volatilization, a little bit of water can be a bad thing,” Laatsch said. “It actually leads to almost a worst-case scenario of volatilization loss because it's enough water to start the breakdown of urea, but it's not enough water to incorporate the urea and hold onto that ammonium.”

Protecting nitrogen from loss, no matter the type

Many products will lump themselves into the category of nitrogen stabilizers. Still, it takes scientifically proven active ingredients with precise chemistries at an effective per-acre rate to protect against losses. Urease and nitrification inhibitors are nitrogen stabilizers that fit this bill. 

A urease inhibitor has a specific mode of action that inhibits the urease enzyme, limiting volatilization loss. A nitrification inhibitor is formulated to slow the conversion of ammonium to nitrate and hold that nitrogen as ammonium longer in soil. 

“That's important because ammonium is not subject to leaching loss — it is retained by the soil depending on its cation exchange capacity (CEC),” said Laatsch. “That's a very stable form of nitrogen, and the longer we can maintain it in the ammonium form and gradually allow it to convert to nitrate in conjunction with the timing of plant uptake, the less loss we're likely to have.”

Connecting nitrogen loss potential to the right solution

KAS offers a range of robust solutions, including ANVOL™, CENTURO™ and SUPERU™, designed to safeguard nitrogen applications from variable weather, timing and soil conditions. These stabilizers secure your nitrogen investment and improve crop yield and nutrient efficiency.

ANVOL urease inhibitor enhances nitrogen efficiency with its patented Duromide technology, particularly in surface-applied and broadcast applications. This reduces nitrogen loss and increases crop yield potential, giving you confidence in your nitrogen management.

CENTURO provides reliable below-ground protection against leaching and denitrification with a noncorrosive formula that integrates easily into your operation for spring or fall anhydrous ammonia and UAN applications.

SUPERU premium fertilizer combines urease and nitrification inhibitors to guard against volatilization, denitrification and leaching, delivering comprehensive above- and below-ground protection. Its ready-to-use, stabilized formulation enables broader, more even spread patterns, covering more ground efficiently.

For more information on these and other nitrogen stabilizers from KAS, contact your local KAS representative.