Nitrogen Fertilizer 101

Nitrogen is the most purchased fertilizer input in U.S. row crop agriculture and the most expensive. In 2026, a 2,000-acre corn operation spends $180,000–$250,000 on nitrogen alone. Understanding the nitrogen cycle, product choices, and pricing dynamics is foundational to managing that cost.

Nitrogen Products and Their Economics

Product	N Content	Form	2026 Price	$/lb N (approx)
Anhydrous ammonia	82% N	Gas/pressurized liquid	$900–$1,100/ton	$0.55–$0.67/lb N
Urea (46-0-0)	46% N	Dry granule	$420–$520/ton	$0.46–$0.57/lb N
UAN 32%	32% N	Liquid solution	$0.28–$0.36/gal	$0.62–$0.80/lb N
Ammonium sulfate (21-0-0-24S)	21% N	Dry granule	$380–$450/ton	$0.90–$1.07/lb N
Ammonium nitrate (34-0-0)	34% N	Dry granule	$400–$480/ton	$0.59–$0.71/lb N

The Nitrogen Cycle in Soils

Nitrogen undergoes several transformations in soil that affect availability and loss:

• Ammonification: Organic N from soil organic matter and crop residue mineralizes to NH₄⁺ (ammonium). Rate increases with warm, moist soils.
• Nitrification: NH₄⁺ converts to NO₃⁻ (nitrate) via bacterial activity. Nitrate is mobile — this is when N becomes vulnerable to leaching and denitrification.
• Denitrification: NO₃⁻ converts to N₂ gas in saturated, oxygen-depleted soils. Up to 30 lbs N/acre/week can be lost in flooded fields.
• Leaching: NO₃⁻ moves with soil water. Sandy soils and high-rainfall years are highest risk.
• Volatilization: Surface-applied urea loses NH₃ gas, especially on high-pH soils or crop residue. Urease inhibitors reduce losses 20–40%.

Nitrogen Sources: When to Use What

• Anhydrous ammonia: Best choice for fall application and spring preplant on suitable soils. Highest N concentration, lowest cost per pound of N. Requires specialized equipment and handler training.
• Urea: Versatile — can be broadcast, banded, or blended. Use NBPT inhibitor (Agrotain) when surface-applying to reduce volatilization losses.
• UAN 32%: Ideal for side-dress injection (V4–V6). Can be mixed with herbicides and pesticides in-season. Higher per-pound cost than anhydrous but superior logistics flexibility.
• Ammonium sulfate: Choose when fields are sulfur-deficient (increasingly common in no-till systems). Premium over urea is justified by dual nutrient supply.

Nitrogen Rate Guidelines

Corn nitrogen needs vary by yield goal and soil organic matter. Standard Extension guidelines for the Corn Belt (Maximum Return to Nitrogen, MRTN):

• 150–180 lbs N/acre for 180–200 bu/acre yield goals on typical Corn Belt soils
• Subtract legume credit: 50–100 lbs N/acre after soybeans, 30–60 lbs after alfalfa (check state-specific tables)
• Subtract manure N: calculate manure application rate × available N fraction from your state's manure nutrient database
• Do not simply add more N beyond MRTN — yield response flattens while cost increases linearly above the optimum rate

Frequently Asked Questions

What is the cheapest form of nitrogen fertilizer?

Anhydrous ammonia (82% N) typically has the lowest cost per pound of nitrogen, at $0.55–$0.67/lb N in 2026. However, it requires pressurized equipment, handler training, and has strict timing requirements. For operations without anhydrous infrastructure, urea (46% N) is the most economical dry alternative at $0.46–$0.57/lb N.

How much nitrogen does corn remove per bushel?

Corn grain removes approximately 0.67 lbs of nitrogen per bushel at harvest. A 200 bu/acre crop removes 134 lbs N/acre in grain. However, total N uptake is higher (roots, stover) — plants typically take up 180–240 lbs N/acre total, with the remainder returned to the field in residue.