Corn and Soybean Farmers Often Apply Fertilizer in November. Experts Say Timing is Key

By Rachel Cramer

With the corn and soybean harvest winding down in Iowa, many farmers are turning their attention to fertilizer.

Roughly 25% to 50% of the total commercial nitrogen applied to fields across the state occurs in the fall, according to a survey led by the Iowa Nutrient Research & Education Council. But to prevent nutrients from flushing into streams and rivers, agronomists say the type of fertilizer and timing are key.

Richard Roth, a nutrient management specialist with Iowa State University Extension and Outreach, said the primary motivation for farmers to apply fertilizer in the fall is to spread out the workload.

Spring rainfall and muddy fields can narrow the window for applying fertilizer and planting seeds.