Heavy August rains challenge Ohio manure strategy

By Joel Penhorwood, Ohio Ag Net

Heavy August rainfall is creating manure storage and application challenges for some Ohio livestock producers.

Ohio State University Extension Manure Management Field Specialist Glen Arnold said parts of his region in northwest Ohio have received six inches or more of rain in August, leaving many manure haulers at a standstill during a time when they would typically be applying manure to wheat stubble and preparing for upcoming silage harvest.

“We’re in a situation where many of our manure haulers are at a standstill,” Arnold said. “Typically, they would be putting a lot of manure on wheat stubble at this time of the year.”

The additional rainfall can also quickly add volume to outdoor manure storage facilities.

“Every inch of water on an acre of ground is about 27,154 gallons,” Arnold said. For a large outdoor manure pond, several inches of rain can mean hundreds of thousands of additional gallons that eventually need to be pumped.

“When you look at someone who might have a five- or eight-acre pond and receive six, eight, 10 inches of rain, you’re pretty close to getting into a half million gallons of extra liquid,” Arnold said.

The extra water also dilutes nutrient concentrations in liquid manure, potentially requiring additional pumping and application time later in the season.

“There’ll be more water and less nutrients,” Arnold said. “It’ll just be some extra work, some extra pumping, some extra time sunk into this.”

Arnold said a return to more typical rainfall through the remainder of August and early September could allow producers to regain some lost application opportunities.

“If we can get back into our regular rainfall patterns, it’ll give us time to recover and get back on track,” he said.

When fields do become fit, however, Arnold encouraged farmers and applicators to remain cautious about runoff risks following the recent wet pattern.

For surface-applied manure, Arnold said setback distances remain especially important. He noted setbacks of about 35 feet from the edge of a vegetated area and around 100 feet for non-vegetated areas, depending on the situation.

“We just need to be super cautious when we get out in those fields again and realize that we could catch some more big rains in the future,” Arnold said. “Observe those setback distances when we’re doing our manure application.”

With additional heavy rainfall still possible, producers should evaluate manure storage levels, watch field conditions and weather forecasts, and avoid rushing applications onto fields where runoff could become a concern.