Regardless of farm size or operation type, manure (or nutrient) management is something every dairy producer must be familiar with. Not giving this area due consideration and planning can have detrimental effects.
Establishing a plan, in addition to proper application with drain tiles, was discussed by Dennis Frame of Timber Ridge Consulting and Eric Cooley, co-director of Discovery Farms, during an April presentation for The Dairy Signal podcast.
Why you need a plan
Not all operations meet the parameters to be required to have a formal nutrient management plan (NMP) in place under the law. Regardless, an NMP should have a place on every farm, according to Frame.
“Today’s plans are really designed to ensure both adequate supply of nutrients (and) to achieve high yields,” he said, “but they try to balance that with a degree of environmental protection.”
This is a mindset different than what farmers and agronomists had even just a decade or two earlier, he noted. And today’s thinking isn’t exclusively about meeting the mounting environmental regulations; a lack of proper nutrient application can have serious consequences for farmers in terms of efficiency, profitability and crop performance.
“You’ve got to be profitable, and you’ve got to be protective at the same time,” Frame stressed. “And it’s a tight balance on that whole thing.”
Of course, no NMP is gospel. It is a strategic plan, but it cannot account for the many things that are out of human control, including weather conditions, equipment failures and the like. However, it is a good guideline to refer to and strive for. To make sure plan details fall within whatever state or federal requirements there might be for a particular operation, many farmers will opt to hire an outside party to develop NMPs for them. However, Frame noted that this should always be gone over after completion to ensure it is achievable and appropriate.
The good news, Frame said, is that in the past eight years especially, plans have improved dramatically. This includes accounting for different tillage practices, cover crops and application methods – all customized to each individual farm.
“I always say there are three keys a farmer needs to think about – maintaining or reducing soil loss, reducing phosphorus loss to surface water,” he said, “and today as we move into reducing nitrogen loss to groundwater.”
In each distinct field, the priority of these concerns will change according to specifications like environment, agronomy and topography. And as environmental concerns increase, there may be other considerations as well as being unique to specific regions or states.
Drain tiles – a serious consideration
Tile drainage, while a wonderful management and agronomic tool, Cooley told listeners, adds a special management consideration when applying any sort of manure, fertilizer or pesticide to a field.
The first step to being successful is having good maps of all tile systems in each field. Besides helping at application times, these maps can be used to manage tile systems for routine maintenance.
“It’s not like one of those set-it-and-forget-it type of systems,” he said. “These do require some manual inspection and maintenance.”
At a minimum, tiles should be evaluated on an annual basis, typically in the spring of the year when the snow melts or after a significant spring rain. This will make things like blockages and blowouts easily identifiable.
Time of application and conditions can also have an adverse effect on application. Any additional liquid or water added to a field, such as with manure, during very wet or dry conditions can be problematic and lead to it flowing out through the tiles without proper filtration.
“One of the common statements made is that we should not apply manure when tiles are flowing,” Cooley said. “From a lot of the monitoring that we’re doing … we’ve seen a majority of those tile systems flowing almost 365 days a year. So it’s really important to understand the individual footprints of your tile systems.”
This knowledge can also help operators identify any warning signs – such as a change in water color or an increased flow – for each individual tile system.
Prior to any manure application, drainage should be restricted. If water control structures are in place, Cooley recommended inserting stop logs to prevent flow before application. Tile plugs, he said, can be used but often fail.
No-till systems need to be paid careful attention during application as liquids can move very quickly into tiles. This is especially true after a dry season that has led to significant cracks in the soil.
“If the soils show these really large cracks,” he said, “we can either have a reduced initial rate to try to get them to swell back up … or we can actually wait ’til a small rain event to help swallow soils up before making a manure application.”
Light pre-tillage, or tillage in concurrent with application, can help break up the “preferential flow paths,” or cracks in the soil, and help slow the descent of manure into tiles.
Part of good management practices also includes ensuring no excess nutrients are applied to what the soil’s needs are, looping back to having an established NMP. Some circumstances that can help prevent this include utilizing cover crops or other surface protection that help retain soil nutrients.
“We’ve really seen some benefits in those tile systems from some of these practices that have been implemented,” Cooley said.
Finally, Cooley cautioned that all farms should have some emergency plan in case of the unfortunate event of a manure spill. Farmers and all involved employees should know the appropriate emergency numbers for their region to report spills and what immediate steps should be taken.
As soon as manure has been found to enter a tile drain, Cooley says the outlet should be immediately blocked, diverted or intersected. After that, a pit can be dug down to collect as much of the runoff as possible.
PHOTO: Staff photo.
