Protecting Water Quality Between the Rows

Protecting Water Quality Between the Rows

Applying nitrogen, phosphorus and potassium found in livestock manure to growing field crops is an economical way to recycle the readily-available nutrients. To protect downstream water quality, farmers and Ohio State University researchers have been working together to ensure these nutrients stay in the fields while also contributing to the crop’s growth.

One such farm striving to utilize manure produced by their livestock is Stateler Family Farms, a Blanchard River Demonstration Farm site. The Statelers started working with Glen Arnold, Ohio State University (OSU) Extension field specialist, manure nutrient management, to utilize their liquid swine manure in an efficient fashion – economically and environmentally. They accomplished this by applying manure to their emerged cornfield.

New equipment needed

There is a growing interest in this practice, but the equipment is a farmer’s biggest hurdle. “Most liquid manure from larger farms is applied by commercial manure applications and their equipment is currently not set up to go through cornrows,” Arnold said.

In order to implement this practice, the Statelers used a toolbar fitted to pull a drag hose to knife the manure into the soil between the cornrows at the V3 stage of growth. The hose was connected to a frac tank which sat at the edge of the field.

However, logistics have greatly improved in the last few years and are getting easier for farmers who are looking to implement this practice on their farms. Arnold recommends modifying smaller manure tankers to travel down cornrows or working with relatives or neighbors to get a drag hose system that works with their current tractors.

Time is an important factor

Side dressing manure requires the application to take place during the early stages of growth if using a drag hose. In addition to the application of nutrients during an important growing stage, manure side dressing can provide moisture during a dry season. A wet spring can prohibit a farmer from entering the field, but the additional moisture from this practice would not harm the crop. A manure tanker, modified to travel down cornrows, could provide a much wider application window for most farmers as the corn could be much taller than the drag hose allows.

Profit and environmental potential

Arnold and his team say the Statelers’ results mirror the results throughout the state. “Statelers yielded about 35 bushels better than their fields with 28%,” said Arnold. “These farmers are using a product that they already have on hand and are seeing great returns. Typically, we see a yield increase of more than 12 bushels per acre.”

“Side dressing manure is proving to be a practice that allows farmers to use a product already available on the farm and aligns with 4R practices. Glen Arnold and his team continue to improve the process and available knowledge so more farmers throughout the state can try this out on their farm.” – Aaron Heilers, Project Manager

Applying manure to a growing crop aligns with the 4R Nutrient Stewardship principles which provide proven best practices for the application of nutrients. Fall soil testing has also shown that the plants are using the available nutrients during the growing season.

Statelers and other farmers throughout Ohio are seeing that manure side dressing can be an efficient use of nutrients. While water quality data from the soil surface and field tile monitoring was inconclusive, the manure-applied fields did not show a “spike” in soil phosphorus while using a product that is readily available on their livestock farm. •

Learn more about subsurface nutrient application.