Fertilizer, diesel costs remain elevated heading into fall

Fertilizer and diesel prices remain well above recent-year levels, adding pressure to farmers making fall input decisions for the 2027 crop. USDA data analyzed by the University of Illinois shows anhydrous ammonia averaged $915.50 per ton on August 7, up 16 percent from a year ago. DAP averaged $912.22 per ton, seven percent higher than last year. Potash prices have been more stable, averaging about $500 per ton. Diesel has been more volatile. After reaching nearly $5.50 per gallon in May, the Illinois average fell below $4 before climbing back to $4.65 on August 7. That is more than 50 percent higher than the same time in 2024 and 2025. University of Illinois researchers say farmers may want to diversify fertilizer purchases rather than waiting for prices to fall. They also recommend reviewing application rates, using soil tests, and following maximum-return-to-nitrogen recommendations. Higher soybean returns could also encourage more soybean acreage in 2027.