The roadmap to next season

September 1, 2026 | Kriss Nelson

Iowa Soybean Association Conservation Agronomist Brock Webb says fall is ideal for evaluating crop performance. “It's one of the most important times for conservation because it allows farmers to look back at the growing season and use that information to make better decisions for next year,” he says.

While cover crops and reduced tillage dominate conservation conversations, Webb says nutrient management deserves more attention — especially with high fertilizer costs.

“It's one of the biggest opportunities farmers have to improve profitability and conservation at the same time,” he says, encouraging producers to evaluate what is in their fields before buying inputs.

Evaluate before you apply

One of the most valuable post-harvest tools is residual soil nitrate testing. Webb recommends collecting samples before the ground freezes. Sampling the top 12 inches provides the greatest value; a 12- to 24-inch sample shows whether nitrate moved deeper.

Rather than averaging an entire field, he encourages sampling individual management zones.

“This is probably the single most valuable measurement farmers can take after harvest,” Webb says. “It tells you how efficiently nitrogen was used and helps fine-tune future nutrient management decisions.”

The results reveal unused nitrogen, over- or under-fertilized areas, and where nitrate is vulnerable to leaching.

Corn stalk nitrate testing indicates whether nitrogen applications were deficient, adequate, or excessive. Grid soil sampling measures phosphorus, potassium, pH, and organic matter to build recommendations based on field conditions rather than assumptions.

ISA conservation agronomists help producers review soil tests and nutrient plans to identify opportunities for improvement.

“We can sit down with farmers and help them understand what the results are telling them and how to use that information next year,” Webb says.

He also encourages livestock producers to know the nutrient value of their manure before applying it.

“I talked to a farmer recently who was applying hog manure, and when I asked what the manure analysis was, he didn't know,” Webb says. “That’s really the baseline for everything.”

Without understanding manure nutrient content, farmers risk overapplying fertilizer and increasing costs.

“Fertilizer isn’t getting cheaper,” Webb says. “Invest in understanding what's in your soil and what your crop actually needs.”

Building on conservation

Fall is also ideal to establish cover crops and reduced tillage. Together, they keep soil covered, improve water infiltration, reduce erosion, and hold nutrients in place.

“Over time, those practices build healthier soils that are more resilient and productive,” Webb says.

Heavy rainfall caused erosion across Iowa this year. While Webb observed erosion even in no-till fields, combining no-till with cover crops consistently provided the greatest protection.

For Webb, conservation relies on data-driven management. “If a farmer could build one habit every fall, I’d say focus on nutrient management,” he says. “Stay on top of understanding what’s left in your soil. The more information you have, the better decisions you can make.”

Email the ISA conservation agronomy team at conservation@iasoybeans.com.

Contact Kriss Nelson at knelson@iasoybeans.com.

Written by Kriss Nelson.

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