“I like to say we’re the best kept secret in Shawano County,” says Steve Peterson, AgSource Laboratories’ vice president of laboratory services.

Indeed, for 50 years now the AgSource lab on the main downtown street in Bonduel has been a fixture. But the unassuming brick façade hides a beehive of activity inside, where soil samples go through a variety of laboratory processes so information can be returned to farmers and landowners so they will know what kinds of fertility levels they are dealing with.

The red brick headquarters building has a small footprint on Bonduel’s main drag, but inside and behind it is an array of sophisticated equipment that provides important information on what has been found in the soil samples.

The whole process begins with soil samples that arrive by mail or UPS shipment or from routes run by staffers in Wisconsin and Illinois. Once those samples arrive in a newer building, built in 2006 and tucked behind the brick laboratory, they get unique identification numbers and the analysis starts. First, samples are dried down in a specially built “oven” – a room with heat and fans that bring it down to a moisture level that allows the rest of the testing to take place.

With use of this heated space, set at about 100 degrees Fahrenheit, the lab can process 3,000 samples per day. The soil samples are also run through a flail grinder to process them for further testing. So that it won’t affect any of the tests, the grinder is built from non-reactive stainless steel.

In addition to getting a unique identification number, the samples are also assigned an account number, because certain landowners or crop consultants may have a unique package of information that they need run on that sample. At a minimum, each sample gets five tests run on it, but the lab can test up to 25 different components in the soil.

Chris Clark, the lab’s sales representative said they have 2,500 different accounts and many of them want different packets of information from their samples. “Nobody’s simple anymore,” she added. “And we have had to keep up with technology.”

Testing of lawn and garden samples may include tests for soluble salts for example.

Some of the technology is high-tech and some is low tech. One of the latter is the use of three different calibrated scoops to test for various components in the soil – a 5 gram scoop for organic matter, a 1.5 gram scoop for phosphorus and potassium and a 7.5 gram scoop to test for pH.

“A lot of this methodology was worked on through the University of Wisconsin,” said Peterson, “probably in the 1950s.”

Peterson notes that no two soil labs are the same. “All of these labs are built by someone’s ingenuity or the availability of space.” A big day of soil sampling, when he started working at the Bonduel lab, was 10 trays equaling 500 samples. Now, a big day would be 3,500 soil samples.

In addition, these days the lab also does manure and tissue sample testing. As those tests became available, the lab added an oven to dry down the manure samples which are tested for their levels of key nutrients – N, P and K – as well as pH and electrical conductivity. Farmers test their manure in order to know how to best use it to feed their crops; but the Bonduel lab has also tested things like zoo manure.

Luckily, manure samples usually come to the lab frozen. Once testing is completed, they are stored in a frozen state as well.

Plant tissue analysis is done at the lab for a variety of Wisconsin’s specialty crops – potatoes, Christmas trees, apples and cabbage (grown for sauerkraut). Spring and fall are the lab’s busiest times for soil sampling, and manure “trickles in” all year. One large client does a lot of soil sampling from May through July.

The lab employs from four to 15 people, depending on the season, and all are cross-trained on other jobs so they can keep the laboratory processes running like a well-oiled machine.

Some of the high-tech equipment used at the lab includes a flow injection analysis (FIA) system for phosphorus and other components. The lab also has two Inductively Coupled Plasma (ICP) systems for elemental analysis that can read multiple elements simultaneously to determine the levels of calcium, magnesium, zinc and others in parts per million.

A lower tech process is used to test for organic matter. Specialized, tiny crucibles – each with its own unique weight and identification – are filled with soil and then loaded into an oven where 680-720 degrees Fahrenheit temperatures burn off the organic matter. By knowing the weight of the samples before and after the organic matter is burned off, that information can be calculated.

Peterson notes that over the years the high-tech equipment has gotten smaller and less expensive. The first ICP or Inductive Coupled Plasma machine was about $110,000 but now they are more in the range of $75,000 to $80,000. “What’s exciting about this technology is that the new versions will take up half the space,” he said.

Since the 1980s, the Bonduel lab has undergone four or five remodels or revisions to make way for the new technology and along the way has added new tests and services.

Potato growers have benefited from tissue testing of leaf petioles from June through August, as those plant tissues are tested weekly so that the proper nutrients can be added throughout the growing season as the plants need them. The tissue testing has also been embraced by cranberry growers and can be valuable in production of alfalfa, soybeans, oats and wheat as well as apples, blueberries and corn. The lab has offered this kind of testing for the last 15 years.

The state’s budding grape industry has also taken advantage of this kind of plant tissue testing and the lab runs similar samples for grape growers in Iowa and Illinois.

The building in Bonduel which has housed the soil lab for 50 years has a history twice as long. It was originally built as a mercantile store and then at some point became a grocery store. Its life as a laboratory began when it was set up as a milk testing lab – back when there was a lab set up to test dairy farmers’ milk in every Wisconsin county. By the 1960s, because of its fairly central location, the Bonduel lab became a regional milk lab for dairy herd testing done in Shawano, Oconto, Marinette and Forest counties.

By 1967, the lab was home to soil testing along with milk sample analysis but then in 1978 the milk lab moved to Appleton, making way for the Bonduel lab’s specialized future in soil analysis. The year that the milk lab moved out, 1978, is also the year that Peterson joined the team in Bonduel, shortly after graduating from the University of Wisconsin-River Falls.

Tissue sampling and the high-tech ICP equipment became part of the lab’s repertoire in 1986 and manure sampling was added in 1990. Field staff members were added in 1995. For years, Peterson said, the lab also did forage testing and handled the World Forage Superbowl that is part of World Dairy Expo. That aspect of the business was sold to Dairyland Labs in May 2012.

That change allowed the Bonduel lab to expand on the soil side and manage the daily workload more efficiently. Soil sampling, an essential part of farming with a nutrient management plan, expanded as more farmers began to have individualized nutrient management plans.

The lab has also found ways to be a good citizen in Bonduel. When soil samples are no longer needed, leftover soil has been available for residents to pickup to add to their garden or fill low areas on their lawns. Local cemeteries have picked up the soil as well.

Over the years the lab has added services, improved and added to its testing protocols and looked for ways to better serve its clients. Peterson re-worked the information sheet after talking with focus groups of clients and incorporating their ideas on information they wanted to see in their reports.

Back in 1967 the lab ran 5,301 soil samples for the year. Today that same number of samples is run in a day and a half.

Jan Shepel is a freelance writer, with more than 30 years experience writing about agriculture. She and her husband operate a dairy farm in Dane County, WI.

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