Handling Manure: Cold Weather Implications

Not testing manure for nutrient content is like buying fertilizer without asking for the analysis.

One thing is certain in animal agriculture. There is manure, and it happens year-round. But handling that manure changes with the seasons. The weather has major impacts on manure application strategies, and winter manure handling brings additional considerations. Snow cover, winter precipitation, frozen ground, and winter melts all complicate the management of manure.

Climate change predictions indicate that wetter winters, more extreme storm events and weather variability will create increasingly challenging conditions for farmers needing to apply manure outside of the growing season. Manure management in the Northeast is only going to get trickier.

Peter Wright, formerly of New York State National Resources Conservation Services, addressed some of these concerns at the recent Dairy Environmental Systems and Climate Adaptation Conference, held at Cornell University. The impacts of climate change, Wright said, will be accompanied by increased environmental regulations, including water quality management. Decreasing the carbon footprint of agriculture will become a main focus, and mitigating greenhouse gas emissions and eliminating runoff concerns will play a major role in farm manure management decisions. With all of these pressures, managing manure with as little detrimental impact as possible will require changes in handling.


Manure is a nutrient-laden, all-natural fertilizer, and its use in crop production is an important part of the equation on most farms. Whether deposited by rotationally grazed livestock, spread in its solid form, stored and applied in its liquid form, composted, separated or anaerobically digested, manure in all of its forms needs to be handled appropriately.

Proper manure management will help to reduce runoff from fields, as well as to reduce odors and greenhouse gas emissions. Nitrogen and phosphorus, both present in manure and both of which contribute to eutrophication of waterways, can run off of fields,. In addition, volatilization of nitrogen left on the surface of the soil causes the release of nitrous oxide, a greenhouse gas.

“It is critical for farm managers to understand that while we may not notice a loss of a pound or so of phosphorus per acre, if there are enough farm acres in a watershed, this is enough phosphorus to potentially have significant impact on water quality,” Karl Czymmek, Senior Extension Associate, Prodairy Field Crops and Nutrient Management, Cornell University, said. “It is also critical to understand that phosphorus losses happen with or without manure application: fields that are fertilized and have runoff or soil erosion are contributors too.”

While manure isn’t the only contributing factor to runoff, proper manure application, year-round, is warranted. Managing manure through daily spreading, which is less and less common as farm size grows, eliminates the need for manure storage, but applying manure under adverse conditions is not an acceptable practice. If precipitation is predicted in the next 24-48 hours, soil is saturated, snowmelt is predicted, snow coverage exists, or when the ground is frozen, spreading manure isn’t a good practice.

piles of manure in cold weather
Photo courtesy audaxl/istock

Spreading manure in the summer, when the crops can actively utilize the manure nutrients, will become one standard method of reducing winter manure application concerns. Increasingly warmer summers will be conducive to double cropping, Wright said. Because less than optimal weather conditions for applying manure in the colder months are expected to increase, increasing manure storage volumes, separating out manure solids and covering liquid manure storage need to become standard practices, Wright said.

There are other risk factors which that intensify the negative impacts of winter manure spreading. Sloped land, proximity of surface water, tile drainage systems, inlets and ditches, liquid manure and lack of crop residue or cover all negatively impact manure application. The method of manure application also has a substantial impact.

Applying manure

While more farms store their manure in some form prior to its field application, situations still arise when the manure storage is full, and the manure needs to be applied to the crop outside of ideal conditions. Although solid-liquid manure separation and coverage of liquid manure storage will help to increase storage capacity, in general liquid manure is more likely to run off when spread on fields than is manure in its solid form. No matter the form, some states ban spreading during certain months, while others have restrictions limiting the conditions under which application can occur.

“Manure spreading in Vermont is banned from December 15th through April 1st,” Scott Magnan, a custom applicator in St. Albans, said. “Adequate storage through those months is needed. The farms in the area have made huge improvements to structures and in management practices to control runoff. If broadcast spreading is needed late in the year we try to apply to low runoff areas away from stream and waterways.”

Contact with the soil is important in preventing runoff from occurring. During spreading of manure, the time period during which the manure can dry is critical. Liquid manure is more likely to runoff after surface application, no matter the weather conditions.

“The main concern is that manure runs off of the soil when rain or snow comes. A period of time when manure is in contact with the soil, crop residue, or cover crops, without precipitation, reduce s the chances of runoff losses,” Bill Verbeten, of Empire Ag Imagery LLC, and formerly of Cornell Cooperative Extension, said. “Partially or fully incorporating the manure into the soil,” and doing so when weather conditions are optimal, are best practices for manure handling.

In the winter, getting manure into contact with the soil is complicated by the freeze/thaw cycle, and by snow coverage. Spreading on snow should be avoided, and rain and melting conditions lead to runoff concerns. Because new snow coverage can obscure where manure was recently spread, marking the end-point when spreading frequently can decrease overlap.

“In the past we have spread on snow covered ground, but as environmental regulations become stricter, this practice is avoided. We have been able to inject manure into one to three inches of frost with our current injector,” Magnan said. “If the frost becomes much deeper, we can no longer pull through. We have also had issues with frost when the top starts to melt and the tractor spins out on the slick surface.”

Injecting or incorporating manure into soils with this critical one to three inches of frost is one of the best tools for winter manure application. Spreading, too, works well during this occurrence, if it is done where significant crop residues exists, and if local laws allow. Some residues, such as hay, offer more protection from runoff than others, and heavier residue is preferred.

“It’s a wonderful way to apply manure,” Wright said of frost injection. “But it may not be a way you can count on,” moving into the future, as changing weather patterns may create less of an opportunity for the proper conditions to occur.

Proper conditions for frost injection develop rapidly. Above freezing daytime temperatures, plus bare soil and night temperatures which that fall below freezing combine to create the frost layer. This frost layer can support heavy equipment without compaction.

Magnan is purchasing a new injector this fall, which utilizes uses disks instead of points. This “cuts and rolls” instead of “pulling and ripping” through the frost layers, and the machine is designed specifically for these harsh conditions.

Equipment and storage preparation

“Equipment preparation is important, and all tanks and pumps should be drained at night. Plug in the block heaters on the tractors at night. A few minutes spent at shutdown can save you hours the next day,” Magnan said. “Accurate spreader calibration means less chance of runoff from over-application. GPS equipment helps in accuracy, and flow meters and valves on tanks allow rates to be set.”

Wright advised that farmers plan on separating manure solids out, capturing value for use in bedding. This also decreases manure hauling costs “because you’re not hauling all that liquid.”

Storage for liquid manure should be covered, eliminating rainfall and capturing greenhouse gases. Without covers, and without designing storage to account for the increased winter rainfalls predicted for the Northeast region, manure storage facilities will be inadequate. With winter field conditions for manure application also increasingly limiting application windows, combined with increased environmental regulations, farmers will be facing a crisis if manure storage capacity isn’t adequate. Filled storage leads to application at “inopportune times,” Wright said.

pile of manure
Photo courtesy holdeneye/istock

Management of tile drainage systems is another area which that Wright recommends improving. Blocking drainage after harvest, to allow the soil to absorb nutrients, and the use of bioreactors, joined to every tile line, are needed improvements to nutrient handling. Both phosphorous and nitrogen discharges from tile drainage will increase with warming trends, Wright said.

“Tile can improve drainage, but it’s impact on manure runoff can be quite variable,” Verbeten said. Increased

Tile drainage areas are already known to be hydrologically active areas of concern. Applying manure to fields where tiles are flowing from field drainage is risky as runoff issues are highly likely to occur.

If winter weather conditions are not optimal for manure application, yet storage is inadequate, reducing the manure application rate, applying manure to fields with the least chance for runoff issues, and applying smaller amounts of manure more frequently, rather than a large amount at once, are some recommendations to decrease negative impacts.

“Manure management is among the top priorities for farms that are positioning themselves for the future. This will mean having manure systems that can function in a range of expected weather conditions and enough manure storage capacity to avoid applications in poor conditions such as when the soil is frozen solid or when significant rainfall or snow melt is expected,” Czymmek said. “Anything we can do to keep soil, residual nutrients and manure on the land will help us to maintain productivity of farm fields and will limit offsite degradation where the extra fertility can create problems.”

Cover Photo Courtesy Scott Magnan

What You Need to Know About Autonomous Vehicles

image of a tractor

An autonomous vehicle could change the way your farming is done. Here’s what to consider.

Artificial intelligence and robotics are becoming more ubiquitous in every facet of our lives, including in how farmers run their operations. The future of semi- and fully autonomous farm equipment is closer than you think. Understanding present and future technology and considerations for when to adopt it is an important financial decision.

How technology is evolving

A survey from the University of Nebraska-Lincoln found that 80 percent of farmers use GPS navigation systems. However, technology for semi-autonomous and autonomous is still in a conceptual phase. Yet Matt Nielsen, corporate communications manager for Autonomous Solutions, Inc. (ASI) pointed out, it is very functional. Nielsen explained how the company’s software and hardware technology is integrated into the CNH Industrial (Case IH, New Holland, Steyr, etc.) platform.

“It incorporates a variety of sensors, cameras, GPS, radio, communication … to bring these sensors all together. Then Mobius platform, (ASI’s command and control platform for robotic vehicle operations), is what gives the operator the control of that vehicle or vehicles,” Nielsen said. “Speaking in concept, in a scenario, an operator would be interfacing with those vehicles through a tablet or through a computer at that farmer’s home or job or anywhere to control those vehicles (and) to monitor what they’re doing while freeing him up to do other things as well. Those sensors provide the capabilities to till a field, seed a field, plant a field, and then also to work in tandem.”

Nielsen explained its technology, in conjunction with equipment manufacturers, can resolve two common challenges for autonomous farming equipment. First, the technology can correct coordination between multiple vehicles when they’re using different types of implements or separately sized implements, which has been a recent and common issue. Second, it can identify and avoid obstacles, plus provide the operator with a path around the obstacle and opportunity to clear the obstruction.

Researchers see a progression that is moving into a human-machine collaboration environment. “What we prefer to do is program the machine so when it sees something that it’s not expecting, it (will) ping the farm supervisor,” explained Herman Herman, director of the National Robotics Engineering Center at Carnegie Mellon University in Pittsburgh. “You can imagine you have the path on your smartphone and the tractor shows you the issue on your smartphone. Then you can decide whether you want to remove the tree or to tell the tractor to go around it or do other things. Coupling human and machine, we believe, is the right thing to do.”

Legal considerations

With new technology comes the unpredictability of the law. Todd J. Janzen of Janzen Agricultural Law LLC in Indianapolis explained there is still a bit of gray matter to autonomous vehicles.

“It depends what the machine is doing,” he said. “For most farm activities, (including tillage and harvesting), I think that there’s no law that would prevent an autonomous machine from performing its duties out on the field,” Janzen said.

However, there are exceptions: noting some states have requirements for nutrient application or spraying pesticides that are done by certified operators.

“It’s an open-ended question whether or not a farmer watching the machine from a computer back at the farm would qualify as being done under a licensed or certified applicator,” he said.

Crop considerations

When using semi- and fully autonomous farming equipment, it often depends on the crop being harvested, said Scott A. Shearer, Ph.D., P.E., professor and chair of The Ohio State University’s Department of Food, Agricultural and Biological Engineering Department.

Shearer used apple growers in Washington state as an analogy to illustrate the difference in approach to a more mechanized and potentially fully autonomous harvesting.

“They’re coming up with tree canopy structures that lend themselves to automated harvest,” Shearer said. “If you spread all your fingers out on your hand and you keep your hand flat, that’s pretty much what the tree looks like. Then you have two rows of those and you lean them over at about a 30-degree angle so the branches of the top of the trees touch. If you put your hands at 30-degree angles, underneath the canopy, the apples hang down so you can go through there with a robotic harvester and harvest the apples really easily.”

Shearer highlighted that while harvesting apples with robotics has real potential, it’s not as simple as creating a machine to harvest the fruit. Compared with crops like corn, wheat and soybeans where the tractors are being equipped with more features traditionally handled by the operator, orchard owners and citrus growers must create a growing environment, which requires a 25- to 30-year commitment when they plant to make their orchard or grove conducive for automated harvesting, according to Shearer.

GPS functioning and technical considerations

Most systems are exclusively reliant on GPS; however, Kraig Schulz, president and CEO of Autonomous Tractor Corporation (ATC), noted there are still lingering issues.

“GPS is good, not great. It’s a very weak signal,” he said. “You get fades and sunspots, reflections and ionospheric interference, and all sorts of challenges that make GPS good most of the time, and then not great sometimes.”

Schulz explained the real-world potential for GPS errors based on the how the system works. Satellites orbiting the earth transmit a signal through the atmosphere, notably the ionosphere. Refraction occurs due to the ionosphere’s varying thickness. When the signal is refracted, errors emerge in the GPS signal.

Base or real-time kinematic (RTK, a satellite navigation technique used to enhance the precision of position data) stations are put in place to correct the errors as best they can. However, the further the RTK station is from a tractor, coupled with processing and communication time and a tractor moving 10 to 20 inches per second, there’s a delay in processing time. Schulz explained that GPS is good at determining where the tractor has been, but not as good at indicating where it is in real time.

What Schulz recommends to improve GPS data is closer RTK stations within the field. The closer to the tractor the RTK correction station is, Schulz explained, the less latency occurs. The shorter distance provided by the RTK correction station to the tractor, compared with the distance between the satellite and tractor as Schulz detailed, the closer the GPS data is in real time to the tractor’s real-time location.

Herman, of the National Robotics Engineering Center at Carnegie Mellon, explained that while GPS systems are improving because the number of base stations is improving, there are environmental factors that can’t be as easily improved. GPS interference can still occur due to towering trees or buildings or even “high faulted transmission lines.” As with Washington state apple growers, step hills can shadow the GPS satellites. Similarly, the satellite’s position – fewer satellites available for signal transmission – can also make it make sensitive to disturbances.

GPS’ role in autonomy

Herman said that if you know where you are, a GPS system would suffice. But in many applications it’s also important to know where you are in respect to things around you, and that’s not captured by GPS.

“In many farms, many people move the collection box, [the] cart or other implements in many places in the field,” he explained. “To make it safe, the robot needs to be able to detect where the humans are located – whether they are on a ladder … sitting on the ground or just walking around, or if somebody parked their pickup truck at the end of the road.”

“We do use GPS so that farmers can use the field work patterns they have already established with their GPS systems,” Schulz said. “We just supplement the GPS data so that we are not reliant on GPS, which has many well-documented issues.” One way to increase accuracy further can be accomplished via an on-farm system.

Schulz’s approach, a product known as Autodrive, provides farmers with on-farm data. Using a laser-radio navigation system, this technology has sensors on the tractor and the field to create hyper-local data for its current location. It provides three safety zones when operating: a 5-foot verification zone, a 15-foot breaking zone and a 30-foot safety zone.

Herman explained how automation research on agricultural vehicles is progressing from playback to nonplayback technology. Using the example of small- and medium-Pennsylvania apple orchards, he explained that one method is to travel through the orchard to train the tractor through all rows and it can “play back that part.” However, if there’s an unintended object, such as a flooded row or a downed tree, it can’t adjust to that unforeseen event.

“The problem with teaching by this playback system is that it’s very inflexible. So if you just use this playback system, the robot can just replicate what you show them, but it cannot come up with a new path or sequence,” Herman said.

For the foreseeable future, instead of using a playback system, Herman said autonomous software will contain a layout of the farm and will be able to navigate from one point to the next by real-time information from its laser scanner and video camera system. While Herman explained a tractor can be programmed to avoid and re-route itself around a downed tree, for example, the next phase is a man and machine working hand-in-hand when an unexpected scenario occurs to maximize safety with autonomy.

Snow Removal and Your Ag Business: It’s Not an Option


Drexler shares her keys to preparedness against the impending snow season.

Paulie Drexler, who runs the tree farm of Springside Farm with her husband, Ed, often thinks about the snow during the beginning of fall. She sees it as nothing strange. “Some may think it’s crazy to talk snow this time of year,” she said, “but then again, we grow and talk about Christmas trees in July.”

For their Fabius, New York operation near Syracuse, which also serves as an agritourism destination, planning for the upcoming winter is a necessity. Drexler shares her keys to preparedness against the impending snow season.


“If you can’t get them in, you can’t sell them anything. That’s the truth,” Drexler said. “You have to look open for business from the highway or else people will drive away. You’re losing business and you don’t even know it. It’s as simple as that.”

It’s the owner’s responsibility to clear the first line of your ag business, she noted: The parking lot. Drexler’s farm uses a 75-hp Massey Ferguson with a frontend loader and snow blower on back. “We use a skid-steer if it gets really bad as the season progresses,” she added. “Sometimes that’s not enough and you need to move large amounts of snow out of the way.”

Having a clear lot is the difference between a satisfied customer and lost business. “We have those who buy trees from us to sell for Christmas,” Drexler said. “If they can’t get in, they’ll go somewhere else. That could be lost business for the next year, too.”


In addition to its snow obligation, the farm’s Massey also plays the role of wagon ride tractor for its agritourism business. When the eventual snowstorm lands, it is difficult to pull double duty.

“After a big snowfall we have to suspend our wagon ride. It is not safe to go through the snow,” Drexler said. “You can’t plow everywhere. Some of your stuff like your seasonal paths start plowing up dirt and gravel and it becomes impractical at a certain point.”

She also pointed out that although the lot and paths are cleared out, some customers may be prone to error and find themselves in trouble. Drexler said the burden still falls on the owner to assist their patrons.

“Occasionally you do get people who are stuck,” she said. “That’s not fun, but you have to be ready for that. It’s nonnegotiable.”


Drexler has heard the horror stories, and she plans not to be one of them. “It’s my responsibility to avoid any hazards,” she said. “God forbid someone gets hurt.”

Hawkish attention needs to be applied, Drexler noted. The first step for safety is preparing ahead of time on the business end.

“You better be ready by Thanksgiving,” she said matter-of-factly, “and make sure you get it done earlier in that day. It gets worse if your equipment isn’t ready to go. That’ll give you a two- or three-hour delay right there.”

Drexler noted that during the season, her crew checks their inventory such as shovels and plows and pays attention to the little things such as making sure the tractor is fully charged and serviceable. “Definitely make sure your tractor is plugged in,” she joked. “You never want to be cussed out by the morning crew. It’s just the way things go.”

She recommends to keep vigilant in clearing and de-icing all walkways and paths. It will be unfortunate for a customer to injure themselves, but it won’t be any better for the owners with any accompanying lawsuits, she said.

“Planning: That’s what it takes. We have skin in the game, and it’s not an option. Your customers matter,” Drexler said. “Farmers are practical by nature. You don’t do yourself any favors by not being prepared.”