Residue management and disease risk

By Stephanie Karhoff, OSU Extension Field Specialist

No-till and reduced-till systems have gained popularity for their benefits to soil health, moisture retention, and erosion control. But retaining crop residue on the surface can also increase disease pressure, especially after a season with high infection levels.

Tillage can be an effective tool for reducing inoculum levels of several crop pathogens. By burying crop residue, tillage accelerates decomposition and reduces the survival of fungi that overwinter on surface debris. For example, fungal pathogens responsible for gray leaf spot and northern corn leaf blight of corn are less likely to persist when residue is incorporated into the soil, where microbial activity breaks it down more rapidly. Specifically, past research in Ohio has