Applying manure in-season

GREEN BAY, Wis. — The ability to give crops the nutrients they need when they need them has prompted farmers to invest in systems that offer flexibility to apply manure while plants are growing and developing.

During a panel on in-season land application of manure Feb. 26 at the Midwest Manure Summit in Green Bay, four farmers explained how they are applying nutrients.

Mike Perry, field operations manager at Double S Dairy LLC, as well as farmer John Schwahn, talked about their use of the 360 RAIN system. Randy Ebert of Ebert Enterprises LLC shared his experiences with irrigation, and Todd Rokey of Rokey Farms LLC discussed the NutraDrip Subsurface Drip Irrigation system.

Schwahn farms about 500 acres near Reedsville and chose to utilize the RAIN system because land is hard to come by in his area and he wanted to improve crop yield. The system is positioned over 160 acres, and Schwahn has been able to gain bushels per acre without extra inputs.

“Manure is applied at the base of the plant throughout the growing season with very good results,” Schwahn said. “When you get manure in that growing crop, it provides a lot of benefits. Applying at the base also minimizes smell.”

Every four days, Schwahn puts on 0.3-inch of a water and manure blend in a banded zone. Schwahn’s system pumps 2 miles in both directions, but he is hoping to eventually reach further fields. “It’s really crucial in that late season to have the RAIN advantage,” he said.

Double S Dairy near Markesan began using 360 RAIN in 2022.

“The machine is out there every day of the year, and we have the option of applying manure throughout the growing season all the way through full tassel and beyond,” Perry said. “We’re also applying a blend into alfalfa, and we see some really nice responses with that.”

The dairy applies a blend that is three-quarters water and one-quarter manure to each alfalfa crop after cutting. Manure is separated by the farm’s separator, and typically the manure in the lagoon contains 3%-4% solids.

“We know how much it costs to apply manure if it’s custom done,” Perry said. “If it contains a large volume of water, it’s expensive to get out but doesn’t have a lot of value. Now, it can be put on a lot of acres close to the farm.”

For the past six years, Rokey has managed 127 acres of subsurface drip irrigation, and for the past four years, he has applied swine effluent through the subsurface drip tape. Rokey said his system is similar to RAIN 360 but with a different delivery method.

Rokey and his brother raise 3,600 pigs in Kansas and farm 700 acres while custom farming another 150 acres of soybeans and corn. Two of their finishing buildings drain into a concrete lagoon which is at the top of an earthen lagoon. Solids and liquids run into the earthen lagoon. Solids are separated by gravity, and liquid enters the irrigation system from the earthen lagoon.

“We’re in rolling country and do not have access to underground water for irrigation,” Rokey said. “We built a pond which acts as a pumping station, and that’s where the manure is mixed with water.”

The sub-service drip system is located 12-14 inches underground. Manure travels in a 3-inch line buried for 1 mile as the hog building is located a mile from the lagoon.

Manure is injected into irrigation water at a rate of 80% water and 20% manure. Rokey puts over a million gallons of manure through the system each year. By utilizing a two-stage lagoon, Rokey said he can get manure solids down to 2%.

“That’s vital for our drip system,” he said. “If there is more than 2%, it has to go through a separation process.”

Rokey cut nitrogen use on corn by a third by applying manure in season and reduced synthetic nitrogen use by about 20%.

Rokey has increased yields above 260-270 bushels of corn per acre. He said the speed of growth from applying in season is key.

“Being able to put nutrients out there when that crop needs it makes a difference,” he said.

The return on investment for Rokey’s system was three years.

“That does not include the value of manure; that’s strictly handling costs,” he said. “This is a system that’s been working very well for us. There are a number of these systems on dairies, particularly in Minnesota.”

Perry said the ROI of their 360 RAIN was also quick. When looking at application costs of 360 RAIN versus hiring a custom operator to pump out manure and leachate, the per-acre difference was $500-$550 solely in application costs.

Ebert and his wife, Renee, are the sixth generation at Ebert Enterprises near Algoma, which is home to a cropping, dairy and beef operation they operate with their children, Jordan and Whitney, and more than 100 employees.

The Eberts have three irrigation pivots: an 1,100-foot pivot covering nearly 100 acres that delivers 400 gallons per minute and takes 40 hours to make a complete turn; a 600-foot pivot covering a little over 30 acres that delivers 600 gallons per minute and makes a complete turn in eight hours; and a 1,000-foot pivot they have not used yet. A weather station in the field monitors wind, and moisture probes monitor moisture.

“Both of those things indicate what we can and cannot do on a given day,” Ebert said.

Ebert uses surface water and a low-nutrient manure source in his irrigation system.

“Irrigation is its own beast; it’s not the same as manure application,” Ebert said. “I’ve been through three permits. Our county has adopted an irrigation ordinance, and we have multiple towns within our county that have an irrigation ban. When people think of irrigation, they think of spraying, but what we’re doing is very different from that.”

Ebert applies wastewater irrigation to corn up to full-tassel silk ear. In 2024, the Eberts planted corn in a circle for the first time.

“We’re trying to get our drop nozzles to follow corn rows instead of fighting through corn rows,” Ebert said.

The low-pressure drop nozzles deliver a coarse droplet that minimizes drift.

“Our approach is to put the least nutrient-dense product through the pivots from a trucking standpoint,” Ebert said.

The Eberts have about 2,500 contiguous acres and started the process of burying a pipeline 17 years ago. This has given them the ability to connect all their acres with a pipeline and connect three production sites through a 10-inch line with 8-inch laterals. The system can handle 1,000-2,000 gallons per minute at less than 200 pounds per square inch.

The Eberts are collecting 20 acres of surface water between their farm sites. Receiving 31 inches of rain on an annual basis allows them to collect 15-16 million gallons of water per year.

“Our goal is to use this moisture on more pivots and do more applications to grow consistent crops no matter what the good Lord gives us for weather,” Ebert said.

Schwahn said he believes in-season application will expand in the future.

“Ten years down the road, I think the majority of manure is going to get hauled in summer, and it will just be maintenance in spring and fall,” Schwahn said. “This will prevent losing the value of that nutrient, as you lose some from fall to spring. Timing is everything.”