Reducing Phosphorus Runoff

By James Hoorman, Hoorman Soil Health Services

Rain is again slowing down spring planting. April and May showers are saturating fields causing nutrient runoff and soil organic matter (SOM) losses.  While most scientists say phosphorous (P) is the main culprit, the harmful algae blooms (HAB) or cyanobacteria need a variety nutrients.  If rains continue into summer combined with warm weather and not much wind, HAB can multiply quite rapidly. Farmers have planted cover crops and applied a variety of best management practices to reduce HAB in Lake Erie, will it be enough?

Where is the P coming from, what is the source?  Human wastes account for roughly 16%, livestock manure 17%, and the biggest source is still from agriculture, from the soil.  Considering the large acreage (4.2 million acres in the Maumee River basin) it takes only a small amount of P loss to cause HAB in Lake Erie.  Farmers generally apply about 35-40# of P on corn and maintain about 95% of what is applied.… Continue reading