In the Field

APPLICATION IN THE OFF-SEASON

When applying nutrients outside of the growing season, certain practices can help minimize losses.

by Amber Radatz

Nutrient applications, from either manure or fertilizer, come with an ever-growing list of items to consider before, during, and after application. Many of these considerations are related to field characteristics or weather and changing seasons.

Since 2001, the Discovery Farms programs in Wisconsin and Minnesota have collected and analyzed water quality data from privately owned farms to develop solutions with farmers for the best ways to protect and preserve water quality resources. Discovery Farms is a farmer-led, water quality research and outreach program led by the University of Wisconsin-Madison Division of Extension in Wisconsin and the Minnesota Agricultural Water Resources Center in Minnesota.

There is tremendous power in understanding the conditions that lead to runoff and risk for nutrient loss. Using that knowledge to make small tweaks can pay big dividends toward achieving sustainable levels of nutrient loss.

Depends on the nutrient

The best time outside of the growing season to apply nutrients depends on the nutrient of concern. In general, nitrogen is best applied close to when the growing crop will use it. This favors spring application. For phosphorus, spring applications can be a higher risk due to elevated moisture conditions and larger storm events, which correspond to more surface runoff. This favors phosphorus application during the drier conditions of fall.

Farming systems, available equipment, location, and other factors will also determine timing of nutrient application. In reality, some fall and spring application will have to occur. Knowing what conditions are important in the fall or spring to prevent nutrient loss is the way to improve nutrient efficiency and protect water resources.

Field day attendees watched equipment made to incorporate fertilizer for off-season application while only disturbing a small amount of soil in each field row.

Considerations for fall

Fall can be an excellent time to apply fertilizer or manure. Compared to spring, fall usually has drier conditions and more time for fieldwork. Drier conditions lead to a lower risk of loss via surface runoff. However, without a few extra targeted management steps, fall application can lead to elevated loss of nitrogen.

For applications of fertilizer or manure with high levels of nitrogen, waiting for the soil to cool below 50°F reduces the amount of nitrogen that might be converted to the nitrate form. The reason for this slower conversion of nitrogen in the soil is attributed to reduced microbial activity because of cooler soil conditions. Nitrogen in the form of nitrate moves freely with water. It is easily leachable through the soil profile and lost to shallow groundwater or subsurface tile drainage before the intended crop can utilize it.

Nitrification inhibitors can provide a week or two of protection in the fall if soil temperatures haven’t dropped below 50°F. Products with known efficacy for inhibiting nitrification are dicyandiamide, nitrapyrin, and pronitradine. These chemical compounds temporarily reduce populations of bacteria in soil that are responsible for converting different forms of nitrogen to nitrate. If nutrient application is earlier in the fall where longer protection is needed for higher soil temperatures, cover crops can be planted to take up some of the applied nitrogen.

Spring can also be an excellent time for fertilizer or manure applications. Surface runoff risks are higher, though, because soils are typically wetter and storms are more intense and frequent.

To reduce risk of nutrient losses in the spring, take a walk through the fields before spreading to assess potential risks to water quality. Note weather conditions and forecasts to assess potential for runoff. Delay applications if conditions for surface runoff are present and the forecast is not favorable.

Wisconsin, Minnesota, and several other states have partnered with the National Weather Service and other agencies to create the Runoff Risk Advisory Forecast. This online tool uses Discovery Farms’ runoff data along with weather forecasting technology to assist in predicting when and where runoff might occur.

Follow recommendations

Also consider the method of nutrient application. In general, incorporating nutrients into the soil profile is preferable. However, if soil disturbance due to incorporation raises the risk of soil losses on your farm, incorporation would be a disadvantage. Knowing your landscape and runoff risks allows proper assessment of this risk. What follows is an example of where incorporation of nutrients or a change in application timing could have reduced losses.

The normal range of nitrate-nitrogen concentration in surface water runoff is 0.05 to 5.2 milligrams per liter (mg/L). When water samples from monitoring stations come back much higher than that range, a nutrient application is sometimes the reason.

On one Discovery Farms site, the nitrate concentration of surface water runoff events in May of two different years were over 30 mg/L and ranged up to 80 mg/L. For this field, urea had been broadcast on harvested soybean stubble in late November after the soil temperature had dropped below 50°F.

Nutrient management recommendations agree with waiting until soil temperatures have cooled before applying any nitrogen, but it is also recommended that nitrogen applied during this time period be incorporated immediately. As soil temperatures warmed in the spring, the breakdown of the fall broadcast urea accelerated.

Minimal tillage in the spring resulted in the nitrate nitrogen produced from the breakdown of urea remaining close to the soil surface. In this case, water quality data confirms the agronomic recommendations of following all of the associated mitigation steps to reduce nitrogen losses to local surface waters.

Before an off-season application, consider the following: • Ensure that crop nutrient needs require this application. • Incorporate nutrients if it doesn’t lead to substantially increasing soil loss. • Wait until soil temperatures are below 50°F for fall applications of nitrogen. • Plant cover crops or utilize nitrification inhibitors. • Assess surface runoff conditions to properly time nutrient applications and reduce risk of loss. ■

Nitrate concentrations of water samples on one farm

Surface runoff nitrate sample concentration (mg/L) 80 70 60 50 40 30 20 10 0

2012 Soybean 2013 Corn

2014 Soybean 2015 Corn

2016 Soybean 2017 Corn

Cropping season

Each dot represents the nitrate concentration of water samples by event in six different cropping seasons. The gray area from zero to 5.2 represents the normal range of nitrate concentrations for Discovery Farms’ sites. Elevated concentrations in 2015 and 2017 are attributed to urea applied in the fall that was not incorporated. The author is co-director of the University of WisconsinMadison Division of Extension Discovery Farms Program.

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Look before leaping into renewable natural gas

As more farms explore renewable natural gas (RNG) options, there are questions that should first be considered.

by Abby Bauer, Managing Editor

newer opportunity in the sustainable energy space is the production of renewable natural gas, or RNG, which is created from organic materials such as food waste or animal manure. After manure travels through an anaerobic digester, the biogas produced is then processed into RNG that can be injected into a pipeline for distribution.

RNG companies are looking at livestock farms to become partners for production sites. While there is a lot of excitement surrounding these new agreements, it is important that farmers know what they are agreeing to before signing on the dotted line. In the webinar, “How to prepare for conversations with RNG developers,” Newtrient’s chief operating officer, Mark Stoermann, offered some insight and questions to consider before making a long-term commitment.

“It’s an exciting time because it’s an opportunity for the dairy industry to have a positive environmental impact but also to diversify the revenue stream,” Stoermann said. However, he pointed out that there is still a lot to learn in terms of putting agreements in writing.

“When it comes to contracts, it’s the Wild, Wild West, and that’s really true. Everybody and every project is different,” he shared. “What you need to do, as a producer, is really think about your operation and your future as you are getting ready to talk to people about these digester projects.”

The biogas produced by an anaerobic digester can be converted into renewable natural gas.

Questions to ask yourself

Think about things that are very practical. For example, Stoermann said that digesters generally work better if they are not filled with sand. So, if your farm is using sand as a bedding material, you may be asked to switch to manure solids. “Is that something you are willing to do?” he asked. There are digesters that run on sand dairies, but he said they require more water and more revenue to be profitable.

Another factor he brought up is that there will be more traffic and more people on your property. Are you comfortable with that?

Stoermann also said to consider your nutrient management permitting and what you are currently committed to do. Then, envision the future of your operation.

“You need to think about the longterm future of the dairy and the project,” he said. He explained that these contracts tend to last 15 to 20 years. If you are not ready to make a commitment for that period of time, you need to talk about it with other people who are part of your dairy.

He said to consider the farm’s succession plan, and who will be taking over the operation someday. “What kind of expertise do they have? Will they want to be involved?” he questioned.

Additionally, determine if you want the developers to provide all the investment for the project, or if you want to invest in it. “That will probably change the dynamics of how the project looks,” he explained.

Know your costs

“Get with your accountant,” was the next advice Stoermann offered. He said you have to know the costs of running your dairy, especially the expenses associated with manure management.

What are you currently paying for permitting, manure collection, manure transportation, storage, and spreading? How valuable is manure to you as a fertilizer or bedding source? Are you getting any carbon credits? Are you willing to take in other products to get tipping fees?

“You really want to look at the whole picture,” he said. These projects require a large capital investment, and while the developer may be footing that bill, they are putting an expensive project next to another expensive project — your dairy.

“You want to make sure everyone will be happy with the project and get a fair return,” he said.

Questions to ask the developer

Stoermann shared these questions to ask the developer before committing to a project: 1. How many dairy projects have you developed, and how many are operating? Can I call and talk to your dairy partners? 2. How long do you need to conduct due diligence on this project? 3. What is the expected project term length? “Always make sure you understand the length of any agreement you sign, and be sure there is a termination of each agreement you sign,” he advised. 4. If significant upside occurs in the RNG market, how will you share that with the dairy? On the other hand, if there is significant downturn, what would you expect from the dairy? “Those are good discussions to have before you are committed and sign contracts,” Stoermann said. 5. What kind of termination clause do you have in the agreements? “It’s always important to have a conversation about termination clauses,” he said. “Everybody has to have a way to have a way out.” 6. Who owns the rights to develop future manure-related revenue? 7. What is your source of capital? Are you open to the dairy participating as an investor?

Again, Stoermann reminded that this is a fairly new market, and it pays to do your homework first. “It is the Wild West in some respects,” he reiterated. “You need to do your due diligence to understand what you are getting into.” ■

To view the full webinar recording, visit www.newtrient.com or email info@newtrient.com.

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Monitoring groundwater at the field level

When it comes to groundwater testing results, what you see is what you get . . . or is it?

by Michael Sklash and Fatemeh Vakili

When a red light starts to flash on your vehicle’s dashboard, it usually means something is wrong with your vehicle . . . but not always. It could be a faulty sensor.

The same is true for monitoring nitrate in groundwater at the local field level. The nitrate concentrations in groundwater from a monitoring well may not be representative of the current farming practices on the property.

Recently, we have been asked to comment on monitoring data for nitrate in groundwater collected from a single monitoring well. We will share two examples that reflect the difficulties with interpreting this type of data.

Results from a single site

The first example started as a hypothetical: What do the nitrate concentration data from a single monitoring well in a field fertilized in part using manure from a larger dairy indicate? Our response began with the “brainstorming” sketch shown in Figure 1.

The monitoring well provides groundwater data from just below the water table, about 50 feet below ground level. The soil is all sandy and extends from ground surface to at least 90 feet below ground level. What do we need to consider with respect to the origin of the nitrate in the groundwater versus current agricultural practice?

Does “legacy nitrate” contribute

Low area focuses recharge Precipitation varies from year to year

Travel time from ground surface to water table

Water table at about 50 feet Single monitoring well on field

Legacy nitrate concentration may vary with depth

Regional groundwater flow with legacy nitrate Irrigation well with drawdown cone

Sandy soil extends to about 90 feet below ground

Figure 1: This is the recreation of a brainstorming sketch of the factors that can affect nitrate concentrations in groundwater at a single monitoring well.

to the groundwater under the field?

Legacy nitrate is nitrate in the groundwater that originated from past agricultural practices somewhere upgradient from the single monitoring well. In a previous article (“Tracking down the nitrate source,” February 2020), we discussed how we can use “isotopes” in the nitrate ion to differentiate between a manure source and a chemical fertilizer source for the nitrate and isotopes in water molecules to estimate groundwater age.

The concentration and origin (manure or chemical) of the legacy nitrate can vary with depth below the water table. Which part(s) of the nitrate does the monitoring well sample?

How long does it take for nitrate to reach the water table under the field? This, in part, depends on how much precipitation occurs, which can vary from year to year. It also depends on the soil (types and spatial distribution) and the depth to the water table.

In our hypothetical example, it takes many years for the precipitation and nitrate from the current year to reach the water table. If farming practices change, when do the effects of the current farming practices show up in the water table?

Low areas in the field can focus recharge from precipitation and

irrigation. How does this affect nitrate movement to the water table? Does the

location of the single monitoring well result in groundwater nitrate data that are representative of the entire field?

If groundwater is used for irrigation, it can bring legacy nitrate to

the surface. Irrigation wells can also homogenize the legacy nitrate in the groundwater to further complicate the issue. Does this affect the nitrate distribution in the groundwater?

The agricultural impacts

So, what does nitrate concentration data from one groundwater monitoring well tell us about the impacts of current agricultural practices? Thomas Harter from the University of California, Davis presented a webinar last fall where he discussed the areal variation in nitrate concentration in groundwater near the water table in a commercial almond grove in California’s Central Valley. The study site was a mile square, intensively instrumented (including 21 monitoring wells in a grid), and had detailed geological information.

Here is what was stunning about this study: Where the area was uniformly farmed, the areal variation in nitrate concentrations in groundwater included a difference of about 80 mg/L between two adjacent monitoring wells about 800 feet apart. Harter’s study site had significant spatial variation in subsurface soil types.

The second example is similar to the hypothetical site. The second problem involved the “background” monitoring well at an existing dairy. The site is underlain by sandy soil with the water table at about 20 feet below ground level. The regional groundwater has high concentrations of legacy nitrate, up to about 80 mg/L in some places.

The legacy nitrate originated from decades of chemical fertilizer use and heavy irrigation for crops. The dairy’s problem was that the nitrate concentration in groundwater at the “background” monitoring well was consistently less than 10 mg/L; that is, it was not representative of the (legacy) groundwater moving onto the dairy property. How could this happen?

We took two actions to find out. First, we installed data loggers in the “background” monitoring well and several other wells to record the elevation of the water table continuously for a period of months. This allowed us to determine the groundwater flow direction at the “background” well continuously. With this information, we could determine whether the regional groundwater, with its legacy nitrate load, was always flowing onto the dairy property or not.

Second, we conducted a large scale, natural tracer test next to the “background” monitoring well to determine where the groundwater originated. A large, spring rainstorm caused ponding of the vegetative treatment area (VTA), which is used to treat part of the nonproduction area storm runoff. The photos show the flooded VTA and the “background” monitoring well.

Three main things happened. First, the data loggers indicated that the water table “mounded” from infiltration of the ponded water in the VTA, compared to areas further from the VTA. The mounding reversed the direction of groundwater flow at the “background” monitoring well; that is, the groundwater with the legacy nitrate episodically stopped moving onto the dairy property.

Second, the ponded water, which was virtually free of nitrate, diluted the nitrate concentration in the groundwater at the “background” well as it seeped into the ground and caused the mounding. This did not occur at monitoring wells further from the VTA.

Third, we were able to test the ponded water and the groundwater around the dairy for oxygen and hydrogen isotopes in the water molecules (see our February 2020 article). The ponded water and groundwater were very different isotopically, but the groundwater at the “background” monitoring well became like the ponded water isotopically.

In other words, when it rained heavily, nonproduction area runoff ponded in the VTA, creating preferential recharge to the groundwater. This caused localized groundwater mounding, blocking of the regional groundwater inflow with its legacy nitrate, and nitrate dilution in the groundwater around the “background” monitoring well.

Two other interesting observations were made. We installed monitoring wells further upgradient than the “background well,” beyond the mounding effect. Data from these upgradient monitoring wells confirmed that the regional groundwater with its legacy nitrate was still flowing toward the dairy (see the first consideration in the first example).

The downgradient monitoring wells at the dairy also had nitrate concentrations considerably lower than the legacy nitrate concentrations. It is possible that because the VTA is located in a naturally lower spot, this area has always acted as a preferential recharge area, long before the dairy was built (see the fourth consideration).

A flooded vegetative treatment area and the “background” monitoring well.

Ask more questions

Do you need to be alarmed by the “flashing light” of the high nitrate concentrations in groundwater observed at a single monitoring well? We suggest that you and the regulators exercise caution when using nitrate concentration data from single monitoring wells to make decisions about your farming practices.

Do the data make sense in the big picture? Are there special circumstances that may skew the nitrate data? Do you need to step back and look at a larger area to help interpret the local nitrate data? Can isotopes and high-resolution water level data help to explain what is going on with nitrate in the groundwater? Ask yourself these questions first. ■

The authors are a senior hydrogeologist and a hydrogeologist, respectively, for Dragun Corporation.

Dairy rations make milk and manure

While a ration is formulated to optimize milk output, we shouldn’t ignore the nutrients excreted in the process.

by Steve Martin

When considering the task of formulating rations, I think about building blocks. When an architect and a contractor work together to build a house, there is a plan and there are materials. Building dairy rations is much the same. Instead of wood, steel, and concrete, we create dairy rations with ingredients like corn, soybean meal, various by-products, and forages.

In reality, though, the nutrition formulation model I use looks deeper. It is not concerned with the use of soybean meal or canola meal, or corn silage or alfalfa hay. It is, however, very interested in carbon and nitrogen as well as various vitamins and minerals. This is science that has been in development for more than 100 years and is getting more complicated by the day!

Nothing goes to waste

The reason I refer to the building blocks concept is that dairy producers buy these nutrients through feed purchases and crop or forage farming costs. Then they sell these same building blocks, repackaged by the cow in the form of butter, cheese, fluid milk, and beef.

The most amazing part is how the microbial action in the cow’s rumen converts items inedible by humans, like wheat straw, corn stalks, and ethanol by-products, into nutritious human foods. Cows are the ultimate “up-cyclers.”

However, the process is not perfect, nor 100% efficient. For every cheeseburger and milkshake value meal at a fast-food restaurant, there is manure that is also created. We won’t, however, call it waste since the cattle industry is excellent in using this co-product for either methane digesters or crop production fertilizer. Nothing goes to waste! Even the solids left over after creating methane can be an excellent, clean bedding option for the cows. The newest technology is even creating perfectly clean water from the “other” product produced by our cows.

Though most of these manure management ideas and plans come from our

Rations that are formulated more precisely save money and reduce unused nutrients being released through manure.

engineering friends, the formulating nutritionist has a hand in the beginnings of the process. How much, though, can my efforts to build rations impact the problems or opportunities of the manure-based products?

Thinking beyond milk

In the dairy world, I think the nutritionist’s role is a bit different than it is for other livestock species. I won’t say it’s harder, but it is different. The beef or swine nutritionists don’t have the opportunity to have their ration adjustments judged by tomorrow’s production measures. In dairy, it is usually no secret if a ration is deemed a good one or a failure, and the decision could come as soon as a day or two from it being fed.

As we think about so many numbers, including milk to feed economics, cow health and reproduction, forage and grain inventory management, and how much protein and fat is in the milk, is there really room left at the table to think about more things? Do the nutrient management implications of the feeds we formulate — those that are not converted into milk or beef but end up in the manure and the urine — have a role?

I grew into my role as a dairy nutritionist in Stephenville, Texas, in the early 1990s. Among other regions of the country that found themselves at odds with regulators, politicians, and the media, the Central Texas dairy industry had an issue with the city of Waco. I am sure the details can be found online, and the struggles were not unlike those elsewhere, but the impact of this issue for me as a young nutritionist was to not add any supplemental phosphorus (P) to our rations. I remember being told by a client that he was more worried about Waco than he was the question of how the level of P compared to the established requirements for what a cow needed in a diet. “We can’t take the risk” was the directive.

At about the same time that this supplemental P reduction was in motion in Texas, we started feeding more and more by-product ingredients that were actually higher in P than primary grains like corn or traditional forages. The fact that P is not a cheap addition to a ration was helpful since removing routine supplemental levels actually was a feed cost reduction for the dairy.

A win-win, it would seem, except for the politics that overwhelmed the situation. The question about whether it was a human source or a cow source of problematic P in the river was complicated by the various area sewer treatment plants in the same area as the dairy farms. I am not sure how the politics and the science sorted itself out in that situation, but the result for me is that I still rarely include supplemental P in dairy rations.

The extras add up

Phosphorus is only one example of nutrients that can be included into diets at excessive levels and either not help or even potentially hurt cows. It may be excessive protein levels in rations that result in a nitrogen loss into the environment or various trace minerals that are fed at a routine excess just to be sure there is enough for the cow.

A dairy nutritionist is quickly judged by their client based on milk production and cow health. At times, the least-risk position for the nutritionist was to be sure there is enough of everything by adding a little extra of many things. With our current intricate nutrition models and complicated on-farm feeding systems, we now have the ability to feed cows building blocks in a more thoughtful manner.

One of the ways to accomplish this is through more laboratory analysis of feedstuffs to be sure we know what we have and only add supplemental levels of nutrients to meet and not exceed guidelines. Feeding groups of dairy cows by their stage of lactation is another way to not only manage feed costs for the producer but also limit unused nutrients that end up in livestock manure and urine. Taking care to consider all of these implications when building diets is the job of a competent and forward thinking nutritionist. ■

The author is the founder of DNMCmilk, which works with dairy producers and heifer growers in several regions of the U.S. and around the world.

The centrifuge at Swager Farms runs at 250 gallons per minute. The water removed from manure enters the centrifuge to be polished, sorting out the smaller particles missed by the screens.

THINKING OUTSIDE

THE BOX This Idaho dairy mixes simple concepts and mechanical systems to best handle manure.

Dairy farmer Dean Swager isn’t one to just maintain the status quo. “If we can do something better, God gave us an opportunity to learn more and be better in our lives,” he said.

He has applied this philosophy to many aspects of his dairy located in southern Idaho. For instance, to more accurately measure feed ingredients for each load of total mixed ration (TMR), Swager created a system using a conveyor belt, a scale, and a trap door that only allows the exact pounds of forage needed into the mixer.

Recognizing the important role water plays in ruminant digestion, Swager also installed a free-flowing water system that runs along the feedbunks. With more water accessibility, “All cows have an equal opportunity to drink water all day,” Swager said, and he found that cows actually eat less feed and produce more milk now. “Anything to bring efficiency up in a cow is a win-win,” he commented.

He applies this “outside the box” thinking to manure management as well. He shared some of the changes he has made to the farm’s manure handling systems and processes in a virtual farm tour during the Pacific and Mountain West Nutrient Cycling, Soil Health, and Food Safety Conference.

Down the lane

Swager grew up on a dairy farm in southern California that was established by his father in 1945. The family moved their dairy to Buhl, Idaho, in 2000, and over time it has grown to their current size of 4,800 milking cows and 1,000 crop acres. Today, the herd of Holsteins averages around 85 pounds of milk per cow per day.

The operation was set up as a flush dairy, which utilizes water to clean the alleyways. “Nutrient management has always been a big focus of mine because of the flush system,” Swager said. “It was a problem that needed to be solved sooner rather than later.”

He said they have tried a “plethora” of manure handling methods over the years. His takeaway has been that in most instances, simpler is better. “Gravity works every day,” he shared. “It has worked since the beginning of time. You don’t need anything but gravity to take out most of the solids.”

Manure is flushed from the freestall barn alleys down into a receiving pit. A pump moves the manure over some coarse screens for initial solids removal. Then, the manure flows down to another pit, where it is pumped into a third pit that feeds a centrifuge. To remove the smaller particles, Swager installed the centrifuge 4-1/2 years ago.

Running at 250 gallons per minute, the centrifuge polishes the water, taking out the solids that the coarse screens miss. Swager explained that when the solids are spun, they stick to the outside of the barrel, just like wet clothes in a washing machine. The solids travel up an incline inside the centrifuge, getting drier as they move along, eventually leaving the centrifuge dry enough to make a cone pile.

The water removed by the centrifuge is reused to flush the cow lanes, while the solids are composted in windrows and then used for bedding in the freestsall barns. He said the amount of reclaimed solids has doubled since they installed the centrifuge.

Swager said that the system requires little maintenance. The screens are pressure washed once a week and are treated with acid when necessary. The centrifuge is shut down once a week to be greased, but that is about it for regular maintenance.

A bonus of installing the centrifuge has been fewer solids in the manure lagoons. “I hardly ever need to clean my lagoons,” Swager said. “Before, it was a full-time job, cleaning at least one lagoon every year. Now, that’s not necessary with a centrifuge. You could see tire tracks at the bottom of the lagoon from cleaning the year before.”

When asked if he was satisfied with his installation, Swager said, “Absolutely. I think every dairy farm could utilize a centrifuge in some way or another.”

Out to the field

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ing with trucks like he used to do.

“I needed a better way to not go into the lagoon and disturb the bottom with heavy equipment,” he explained. “Also, I needed a way to remove slurry without taking a year worth of drying, even in ideal conditions, to get that slurry dry enough so it could be hauled out.”

About six years ago, Swager settled on a drag hose system for a simple reason. “It’s a tried and true technology that’s been used for many years, more in Eastern states than here, but if it works there, why wouldn’t it work here?” he shared.

Plus, he was able to utilize drag hoses with the system he already had in place. “We just put the pump in and start pumping. There’s no prep involved,” he explained. “And no one is covered in cow manure at the end of the day.”

Another benefit is that the manure is applied more precisely. “It puts the nutrients where you need the nutrients. They are not on the surface; it puts them down below, where it’s plant available,” he explained.

On a good day, he said they are running 1,000 gallons of manure per minute through the injectors, “so we can put a lot of product down in a short amount of time,” he noted.

The draglines are only used for about a month out of the year. He said maintenance includes the basics, such as diesel fuel, oil changes, and filters. As for the drag hoses themselves, he said they usually last about three years before needing to be replaced.

When comparing the cost of the current drag hose system to his former method using tankers and hiring someone to pump out the lagoon, he said he was able to pay off the drag hose system investment in a year and a half to two years.

As for the crops, “Our yields are so much better now. The crops are so much better now,” Swager shared. “They are not affected by spreader trucks driving over the fields and creating compaction.” He also reiterated the benefit of putting the nutrients down in the soil.

“It’s just a way better system for putting nutrients on,” he said.

Looking forward, Swager said, “Ultimately, we need to keep the nutrients out of the lagoon. That’s what dairy farms need to do. But for today, this is a great way to mitigate problems.”

As part of the farm’s nutrient management system, screens remove the solids from manure. These solids are composted in windrows and are then used for bedding in the freestalls.

Better air for all

Swager also worked with the University of Idaho to install a trial zeolite filter on his dairy. Zeolites are minerals of volcanic origin, and one of the most abundant and commercially available zeolites, clinoptilolite, is mined in Idaho. A filter made using this zeolite has the potential to reduce ammonia and other emissions from stored manure.

When approached with the idea, Swager was willing to give it a try. “Systems that can reduce ammonia emissions on the farm would be a great plus to the industry,” he said.

His early opinion about the filter was encouraging. He noticed a drastic reduction in ammonia emissions.

“The zeolite filters are a low-cost option to solving a bigger problem,” he said, noting both reduced emissions and less odor. “I am all about anything positive the dairy industry can do for the environment.”

Swager finds partnerships with the state’s university to be valuable, and he appreciates the work they do. “The University of Idaho does excellent research, and they are always looking for the next step,” he said. “If we simply do the same thing over and over, we can’t expect different results.”

Swager considers himself to have a “why and how come” type of mind. “I like to test why things work the way they do,” he said.

His advice to other farmers was to adopt a similar mentality. “We don’t just have to do things like Dad did because it worked for him,” Swager said. “Ask yourself, ‘Can we do it better?’” Swager doesn’t have a specific plan yet as to what is next for manure management on the dairy, but his eyes and ears are wide open for new ideas that could improve his farm and the world around it. ■