U.S. anhydrous ammonia prices jumped 15.9% to $945 per short ton in the week ending Oct. 7, the steepest gain among nitrogen products tracked by FertilizerPrice.com, as farmers harvesting the 2026 crop absorb a fresh round of input inflation heading into 2027 planting decisions.

UAN32 climbed 15.7% to $645 per ton and urea rose 9.1% to $796.25. Potash added 6.8% to $571.35.

Why are prices diverging?

National averages masked the move's unevenness. UAN28 fell 11.1% to $533.34, DAP slipped 1.7% to $945.56 and MAP dropped 3.8% to $978. Co-ops and retailers are quoting widely different delivered prices across the Corn Belt based on product, geography and timing, which makes weekly benchmarks market indicators rather than a stand-in for local delivered bids.

What does this mean for 2027 fertilizer bills?

The weekly data lands on top of a cost outlook USDA already expects to weigh on producers. The agency's 2026 farm income forecast projects fertilizer, lime and soil conditioner expenses to climb $5.3 billion, a 15.3% jump over 2025. Fuel and oil expenses are set to rise $4.8 billion, or 28.8%.

Inflation-adjusted U.S. net farm income is projected to fall 5.5% this year. Any further nitrogen rally between now and spring application would deepen those pressures, particularly for corn, which consumes far more nitrogen per acre than soybeans.

How tight are corn margins in Illinois?

University of Illinois economists see 2027 corn returns after all costs, including cash rent, at just $28 to $36 per acre in northern and central Illinois. Soybean returns are projected at $68 to $86 per acre. That gives soybeans a $40 to $50 per acre advantage over corn at projected prices of $5.00 per bushel for corn and $12.00 for soybeans.

A 50-cent swing in the corn price can shift projected returns by more than $100 per acre on highly productive Illinois ground, according to farmdoc research published in September. Break-even prices sit near $5.00 per bushel for corn and $11.10 to $11.28 for soybeans.

Why does the corn-soybean acreage mix matter?

Corn requires substantially more nitrogen than soybeans, and that asymmetry sharpens when nitrogen prices rise. Rotation rules, local basis, forward commodity prices, livestock feed needs and balance sheets will all shape planting decisions. The relative profitability signal in Illinois currently favors soybeans, and persistent fertilizer inflation could widen that gap.

Growers with rotation flexibility will weigh an additional corn acre against the lower nutrient requirement and higher projected margins tied to soybeans, farmdoc adds.

Which tools can producers use?

Precision practices grow more attractive when nutrient prices rise. Soil testing, variable-rate application, split nitrogen strategies and tissue sampling can stretch each pound of nitrogen further. University of Illinois research recommends evaluating nitrogen rates against expected corn and fertilizer prices rather than repeating historical application levels.

"For growers, the objective heading into 2027 will not necessarily be using less fertilizer, but extracting more economic return from each dollar invested in nutrients," farmdoc researchers wrote.

The next several months will determine whether October's price strength becomes a temporary market move or a lasting component of 2027 production costs. Farmers will weigh local fertilizer bids, global nitrogen supply, energy markets, basis levels and 2027 commodity prices as fall application and purchasing decisions advance.