Is the ground fit?

The annual Hoover Manure Expo held this summer in Chambersburg, PA, featured a panel of manure handlers who discussed in-season manure application as well as challenges with winter spreading.

Eric Rosenbaum, Rosetree Consulting, moderated a panel that included dairy farmers Eric Hoover, Anthony Martin, Clinton Burkholder and nutrient management planner Jeremy Newswanger.

“People have been top-dressing small grains for many years,” Rosenbaum said. “Farmers emptied manure storage in winter until appropriate springtime conditions. People are thinking about emptying storage, soil health, improving forage quality, driving yield as much as possible and focusing on minimizing injury from in-season applications.”

Farmers should be familiar with all state regulations regarding manure storage and application.

Hoover applies most manure in autumn, so after the corn is off, he plants rye or triticale then applies manure. When the crop is four to six inches tall, he applies manure with a dragline.

“It’s going to be ugly afterwards but looks much better in just a week or two,” he said. “With injection, the ground has to be dry enough. If the ground is too wet, I use a dribble bar or splash pan.”

Hoover said the most important aspect of winter manure application is avoiding entering fields just prior to snow.

“If you are spreading with any snow on the ground, the manure is warm and melts the snow, turns to slush, then it freezes,” Hoover said. “There’s a layer of ice on top of the rye, and if there’s rain and cold, it can kill rye. This past winter, pits were full and had to be emptied so we ran the injector in the snow. The ground was thawed and the manure soaked in so there was no runoff. The biggest thing is whether the ground fit for manure – you don’t want runoff.”

Field conditions Hoover doesn’t want to see at application include excessive field wetness, runoff if there’s too much manure in one spot and application timing for growing crops. For those growing spring forage, he advised not injecting into frost because the frost pushes sideways and tears plant roots.

Considering there are many more rural landowners who aren’t farmers, Hoover believes the single biggest improvement in manure application is better odor management and neighbor relations.

One of Martin’s challenges is limited manure storage space.

“We kept adding cows and didn’t change facilities, especially not manure storage, so that added more manure to the same size facility,” Martin said. “We had to not withhold fall application. For winter application, we were limited and only did as much as we needed to, then we picked certain fields to apply based on location or topography.”

Martin discussed the impact of reducing compaction and tires over fields, and whether the definition of a “good manure application” has changed.

“After taking small grain silage off and draglining manure, the soil structure is healthy,” Martin said. “There is a lot more manure and a lot more forage to make, so timing and using manure has changed. Going from a tank spreader to dragline is where we first saw a difference because there had been compaction and crop damage in winter. The dragline helped with compaction, especially at field entrances and exits. We were transitioning from alfalfa strips to double crop rye and corn and that changes field size. With bigger fields, it’s easier to be more efficient with dragline.”

Martin said planting time is what affects crop yield. In autumn, he injects manure prior to planting small grains. However, it’s been challenging to get the correct planting depth. He is cautious to drill no more than a few inches to avoid sinking too deeply.

“With extended snow cover, the ground thaws,” Martin said. “If there’s snow cover and it’s going to rain and warm up, don’t apply if it won’t have time to soak in. The dragline works well but if you are top-spreading on snow, it’ll make huge piles because the hose drags the manure and snow together. With the injector, going through eight inches of snow isn’t a problem.”

Burkholder, whose Burke-Lea Farms hosted the event, said his biggest challenge is maximizing forage on limited acreage. Burkholder’s primary focus is crop quality and how and when manure is applied. Regarding decisions about whether to land-apply manure in winter, Burkholder said that it depends when the crop was planted in autumn and lagoon level.

“We were growing a cover crop and not harvesting forage, so we needed a crop to keep manure application in place to take up nutrients,” Burkholder said. “Now we’re looking at forage production for rations and removing nutrients from soil. We were using a dragline with an aerator, so we were incorporating into the soil and disturbing the soil more. There were ruts in the field, the ash content was affected and it wasn’t good for no-tilling corn back into the same field. It was both accident and necessity for how to manage based on equipment, crops and getting into the fields for timely application and harvest.”

Newswanger discussed changes in how manure is handled in winter, including emptying manure storage over winter to use manure more efficiently and to comply with regulations. He believes injection equipment and draglining have made significant improvements in compaction and crop injury. Timing is also critical.

“Toward the middle to end of March is too late,” Newswanger said. “It depends on how much you’re putting out – you don’t want to use too high a rate. I recommend no more than 5,000 gallons per acre on spring forage crops at one application to avoid knocking it down. Using a dribble bar decreases the risk of crop damage.”

Newswanger said most farmers want to maximize manure and application timing to optimize benefits from manure nitrogen. Less manure nitrogen is lost when conditions are cool and dry over winter.

“People are focusing on the timing of spring applications,” he said. “The goal for dairy cows is pushing protein and getting more digestible fiber. The right place is critical, along with adding sulfur as well as nitrogen because they work together in the plant. Nitrogen at first application via manure or nitrogen at green-up increases yield. Later nitrogen applications several weeks prior to harvest boosts protein in plants.”

by Sally Colby