Record US Corn Stocks Press CBOT Grains as Urea and Ammonia Prices Rebound
US corn inventories on September 1 came in at 2.095 billion bushels, 35% above a year earlier and well above trade expectations, sending December corn to a five-week low near $5.00. At the same time nitrogen costs firmed, with urea quoted at $796.25 a short ton and anhydrous ammonia at $945.00.
The USDA's quarterly Grain Stocks report reset the grain complex. Corn stocks as of September 1 totalled 2.095 billion bushels against an average trade estimate near 1.918 billion and 1.551 billion a year earlier, a 35% year-on-year increase and a seven-year high for the date. December corn futures fell more than 20 cents to a five-week low near $5.00 per bushel on the release, with the contract dropping from an opening level around 522 to a session low near 503.38. The agency also trimmed its 2025 corn production estimate by roughly 57 million bushels on lower harvested area while leaving the yield unchanged.
Oilseed and wheat balances diverged from corn. Soybean stocks came in at 315 million bushels, slightly below the average trade guess near 323 million and down from 325 million a year ago, a modestly supportive result that was nonetheless dragged lower by corn. Wheat stocks of 1.846 billion bushels were close to pre-report expectations but down 14% from a year earlier, and the Small Grains Summary put 2026 all-wheat production at 1.534 billion bushels, some 23% below last year's total. USDA also reported that processors crushed 209.6 million bushels of soybeans in August, below the average trade estimate.
Harvest logistics remain the near-term swing factor. USDA crop progress data showed corn only 18% harvested, matching last year's pace but behind trade expectations, and a wet late summer and early autumn slowed fieldwork across the western Corn Belt. USDA meteorologist Brad Rippey noted the quick pace of soybean harvest across much of the South as a main factor behind the fast national harvest numbers as of September 20, and separately flagged heavy rains across parts of the western corn and soybean belts. Private forecasters have moved in opposite directions, with StoneX cutting its US corn yield estimate to 182.1 bushels per acre from 182.9 while raising its soybean yield estimate to 54.1 bushels per acre from 53.0.
Input costs are moving the other way from grain prices. FertilizerPrice.com's weekly survey showed urea at $796.25 a short ton, up $66.25 on the week, anhydrous ammonia at $945.00, up $129.50, and UAN 32% at $645.00, up $87.57. Weakness was concentrated in phosphates and one nitrogen solution, with UAN 28% at $533.34, down $66.66, DAP at $945.56, down $16.27, and MAP at $978.00, down $38.23, while potash firmed to $571.35, up $36.15. Rising nitrogen costs against sub-$5 corn tighten the margin math for 2027 planting decisions ahead of the October 9 WASDE update.