It takes many steps to find the right rate

Galen Koepke farms in Ottawa County on the banks of the Portage River just a few miles from Lake Erie.

A television crew was at Koepke’s farm within a few hours after the news broke after the Toledo water crisis in 2014. Since then, all agriculture in the watershed has been the subject of great water quality scrutiny, but Koepke is under a microscope.

In many ways, though, Koepke welcomes the attention because he knows he is doing things right according to the 4Rs with his farming practices. This has not always been easy, however, particularly for one 34-acre field that borders the Portage River. For many years, he had farmed and carefully managed the 20-acre field and then around 20 years ago he purchased a neighboring 14-acre field and combined them.

“On that 14 acres they had two large layer operations with a total of around 100,000 chickens and they had spread all the manure on that field for many years. When we bought it and soil tested, we found that the phosphorus was off the charts. It is a relatively sandy soil and it is prone to flooding,” Koepke said. “I think there is probably enough phosphorus on that field to finish out my farming career. We double-checked to make sure that there was no mistake made.”

Doug Uher is the seed and precision specialist for Luckey Farmers, Inc. Cooperative who works with Koepke on the challenging field.

“I pulled a soil sample that I think was 1,200 pounds of phosphorus. I told Galen that I didn’t think this was correct, as this was one of the first years we were doing grid soil sampling. When the next results

Doug Uher and Galen Koepke stand on Koepke’s farm near the Portage River.

Doug Uher and Galen Koepke stand on Koepke’s farm near the Portage River.

came back, we found samples higher than 1,200 — it turns out that 1,200 was the average on the 34-acre field. There was only one spot on the east edge of the field that actually needed phosphorus. I told him he wouldn’t need to apply phosphorus for the rest of his life,” Uher said. “Because this field is located right by a river, it is more of a risk environmentally. We haven’t applied P in 16 years on most of that field.”

The systematic sampling was a crucial part of coming up with a prescription for the right rate in the portion of that field with a legacy of poultry manure — zero. Koepke very clearly understands the value of the right rate in terms of the environment and water quality, but he also understands the economic benefits.

“There are a lot of different soil types from black sandy loam to heavy clay in that field. On the part that we owned before, the soil tests are still calling for phosphorus applications, which makes the variable rate applications really shine,” Koepke said. “With the soil testing we try to do each field every third year and we use prescriptive maps with Luckey Farmers. They do the samples and then I meet with my agronomist and we plan the application accordingly. When we dropped it to 0 P it didn’t change the yields any and it saves money.”

Along with using the right rate, Koepke has implemented numerous conservation practices farm-wide to minimize the environmental impact of his farm. He has a corn-soybean-wheat rotation in many of his predominantly no-till fields, but wheat does not work well in the river bottom fields because of flooding problems. He has also dramatically expanded the use of cover crops in recent years.

The Portage River borders some of Koepke’s farm just a few miles from Lake Erie.

The Portage River borders some of Koepke’s farm just a few miles from Lake Erie.

“I plant soybeans into cereal rye and in my wheat ground I have been using a mixture of oats and tillage radish,” he said. “We can’t plant wheat in our river bottom ground because of the flooding so we aerial seeded oats into the corn this year. We have been using cover crops there for three or four years now. This year I will have a cover crop on all of my acres.”

His work with the Luckey Farmers has allowed him to take his environmental emphasis to the next level.

“As individual farmers we can’t afford the right equipment for the job that Luckey Farmers has,” he said. “I have a vested interest in protecting the environment here. I get my drinking water from the lake too and this helps me to do a better job.”

Luckey Farmers starts the process of developing the right rate of fertilizer long before the actual application with soil sampling. Though there are multiple ways to strategically and consistently take soil samples, each with pros and cons, Luckey Farmers has stuck with sampling on 2.5-acre grids.

“We do 2.5-acre grids but we work with a consulting firm that does it on yield zones. That can be a chicken or the egg thing. Did that part of the field yield 120 bushels because it was fertilized for 120 bushels or because that’s the maximum yield potential for the soil type? We want to come up with the right rate based on numerous factors. When we grid sample now we fertilize based on what is there not what may be there in yield, so I am still a grid guy. In my opinion that is the way to go,” Uher said. “If you base it on soil types, they usually won’t match your yield map because yields can vary over the same soil type. In fields where yields match the soil types then zone sampling works, but that does not happen often. I think in the future it may be a combination of all three things: fertility, yield and soil types. I do

The auto-probe is mounted on an ATV and it is operated by push button.

The auto-probe is mounted on an ATV and it is operated by push button.

know the days of the right rate of 400 pounds of 4-10-46 are not here anymore. Why would a farmer want to over fertilize? We want farmers to make money so we want to put the right rate down.”

Within the grid sampling system, the next step is getting consistent and accurate soil samples.

“This last year we purchased two auto-probes that are pre-determined on soil sampling depth. It is all I-pad based and it geo-references where you pull it. You take a picture of the barcode on the bag holding the sample and that is then geo-referenced. That takes out any room for paperwork error. The traceability and accuracy of the soil samples is a really tight window now. Part of the issue we used to get when we sent an intern out to get soil samples is when it hasn’t rained for three months you can get inaccurate results because the soil was hard. This is much more accurate and repeatable,” Uher said. “That is new this year. We try to do it about the same date every year for each field. We either sample right after wheat or in the fall. We don’t like to sample in the spring. In the spring you can find different levels so that is our last resort for taking soil samples. We target anything going to corn in the fall.”

After developing the sampling plan with the farmer, the samples must be carefully collected and handled.

“The guy pulling the soil sample gets a text describing the job and he’ll go out to the field. The auto-probe is mounted on an ATV and it is operated by push button. Everything is on an I-pad and it really takes out the human error component. On a general soil sample the sampler finds random samples. On the grid, the spots are pre-determined where the probes need to be. We go back and sample the same spots where we sampled before to get a handle on what is happening over time. If it is in a bad location — headland or in a low area or swale — it can be moved. They also need to stay off the rows where fertilizer applications may have been made,” Uher said. “We work with A&L Great Lakes labs in Ft. Wayne. With our new software the results go from the lab to the software company that puts it in and I get an email that says it is ready for precision. It is all automated. Then I go in and put in the crop, yield goals and type of fertilizer used and it tells me a prescription for the field.”

Each of those factors is also important for determining the right rate, particularly the yield.

“You need realistic yields to get the right rate. Many guys have yield goals that are two low for today’s genetics, but I also have guys tell me they want 240 bushels every year,” Uher said. “We are working to do a better job of overlaying fertility with yields. We don’t want a rate for 200-bushel corn in a part of the field that yielded 120 bushels. Yield data is going to be a bigger part of the right rate in the future.”

Uher’s plans for the application include details like the location of the field entrance and numerous types of environmentally sensitive areas. Once an accurate and realistic rate prescription has been developed, it must then be properly applied.

“We create a file that can be uploaded to the application machine. We put it on a flash drive so the applicator will know to apply it like we have it drawn up. We develop the right rate based on our computer model and we make the application based on that,” Uher said. “The applicator then provides an ‘as applied’ map to show exactly how he drove to match everything up. It is a 70-foot boom so I match up with application grids as closely as we can. We are getting a lot better with automation. Now we are starting to do all of it wirelessly.”

In addition, the equipment must all be accurately calibrated to get the right rate on the field.

“We calibrate all of our equipment twice a year and every load that goes out we are spot-checking to seeing if it’s right,” he said. “If we know we are supposed to put on 1,000 pounds and we are 20 pounds off we’ll be able to tell.”

The technology is evolving and improving quickly but keeping up with the changes can be a challenge.

“A lot of the software we use is not based on agriculture and we have to adapt everything,” Uher said. “We have to find what works and what doesn’t and it can be a learning process.”

The end result of this long process, though, is a very valuable right rate.

“In most instances one of two things will happen when guys start with grid soil sampling and variable rate application — his yields with either go up or his fertilizer application will go down,” Uher said. “There is a misconception that when guys get more precision they put less fertilizer on, but that is not always the case. In some cases the grid soil sampling leads to recommendations for fertility that are actually higher and they see a nice yield bump. In the end it has to be profitable for the farmer for it to work.”

This ongoing evolution at Luckey Farmers fits right in with their certification through the 4R Nutrient Steward Certification Program.

“We have always tried to do the right thing but now we have it in black and white. Now we have a standard where we are held accountable to make sure we are doing the right thing,” Uher said. “The certification process really helped us with traceability and it forced us to do a better job with the paperwork. Before if we were asked ‘Do you have a soil sample from four years ago?’ ‘Well yes. But where’s it at?’ We have done a good job of keeping track of what phosphorus levels have done in the fields, for example, and if we see an outlier we know something isn’t right. This certification makes us keep track of things better and helps us to do a better job for our customers.”

The right rate component of the 4Rs is crucial for farm profitability and environmental stewardship, but finding it depends on a long chain of the right people and the right equipment used in the right way, Uher said.

“Did we sample right? Was the equipment calibrated right?  There are a lot of moving parts with the right rate from getting the right soil sample to getting the fertilizer applied.”

For more, visit 4rcertified.org.

 

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5 thoughts on “It takes many steps to find the right rate”

  1. For right rate you need to depend on environment, type of fertilizers, and. I agree with you. These are better steps. Thanks for sharing with us.

  2. At the time that the poultry farms were applying manure, there were only regulations on Nitrogen application. No one at that time understood the issue of Phosphorus and potential impacts to water quality. It was not that long ago that soil tests only listed P as 90 # plus….Today we know better…science has and still is advancing. We still have areas where hogs were fed out on pasture that the soil tests are high on our grids 40 years later.

  3. Yeah! its nice information.

  4. Wow! Thanks for share with us. Nice blog.

  5. Your post is really a great help for people like who are just learning basics.

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