Soil labs: taking them to the fields

The trend is to take real-time tests in the field, but are the results useful and can these be relied upon?

The elusively mysterious analytical assay procedures of the soil laboratory are moving step by tiny step into farmer’s fields.

Every year, more real-time lab-in-the-field products become available to growers.

We recently looked at the new MicroBiometer kit, which became available to western Canadian farmers seven months ago.

The MicroBiometer, which gauges microbial biomass and soil organic matter, joins a list of nearly a dozen devices and procedures that are best described as lab-in-the-field products.

Some of the earlier and more familiar products seeking to circumvent the traditional soil lab include the Veris EC machine on wheels, the Green Seeker and the Plant Root Simulator introduced 20 years ago by Ken Greer of Western Ag Innovations. The PRS, especially, was instrumental in launching this trend.

In compiling this story on the lab-in-the-field trend, we talked to Rigas Karamanos, senior agronomist with Koch Fertilizer in Calgary; John Heard, fertility specialist with Manitoba Agriculture; Don Flaten, soils researcher at University of Manitoba; and Greer. It’s ironic that Greer, himself a commercial ag-tech innovator, was the person who sounded the warning about the trend toward in-field soil test products.

Ken Greer — “Like any gold rush, simply staking a claim on an ag-tech idea can yield profit for venture capital,” stated Greer. He cited the most stunning fall from favour Silicon Valley has ever seen. A company called Theranos claimed to have invented a portable device that could cheaply run a full range of lab tests with just one drop of blood from a pin-prick. The principals of Theranos now face serious criminal fraud charges.

“If you convince someone there’s gold on a claim, you potentially flip it for big profits and never have to invest in the mine, blast rock, sieve, shake or separate gold. The truly valuable ag-tech is a fully developed working gold mine. Flipping claims is not value to farmers. Beware of venture-capital-backed ag tech start-ups. My tip for today.”

He said that venture capital always wants a fast return, but developments in agriculture and specifically in soil science tend to come slowly. He said he’s always cautious if he sees all the money behind an innovation is venture-capital money. When they use the term “patient venture capital” they’re talking about three years. Greer said three years in agricultural science usually can’t accomplish and ground truth any product or service.

He said he’s skeptical of new products in the same way people were skeptical of his PRS when it first came out.

“We’ve been around 20 years with our plant root simulator, and we’re just finally to the point that my friend, Rigas Karamanos, thinks we’re OK,” he said with a laugh. “In ag technology, the only test you really have to pass is the test of time.

“This soil test trend is to take more of a biological look at your farm rather than a chemical look at the farm. That’s what our plant root simulator is all about. It was reading the soil health around a plant root back before soil health became such a buzz word.

“Any of these new tests that look at the biological function of the soil are basically a good thing. These tests belong out in the field because that’s where the soil is living. There’s quite a number of products and devices now that aim at understanding this biological function. These tests are good for understanding our soils and good for farmers because they go beyond NPK. We used to treat soil like a chemistry set. Now we’re looking at how the soil lives.”

Rigas Karamanos — Karamanos said judging from the high number of questions he’s been getting, the new real-time in-field tests are becoming a hot topic.

“The bottom line for any type of soil test is you have to calibrate the data. That’s where all these new tests worry me,” said Karamanos.

“I understand the value of conducting testing in the field. For example, the Veris machine (EC3100) measures salts. It’s also used to delineate variable rate management zones in the field, but it has to be calibrated.

“The Green Seeker is another device that can be very useful, but it has to be calibrated for each crop. Like so many tests we have today, they need to be calibrated to be useful.

“Last year, I saw the laser test demonstration. You point the laser beam at the soil and it gives you an instant reading. It’s awesome technology, but what does the data mean? We don’t know.”

He says the only calibration that’s been conducted on the Prairies is with the Plant Root Simulator, the device he vehemently argued against two decades ago. But now that it has been calibrated for phosphorus, the PRS has become one of his favorite tools.

“This agrology is awesome methodology for phosphorus. It works better than any other method. I have two papers published on it (PRS). But we have no calibration for any other method. We have this debate internally at our company.”

Whenever the opportunity arises, Karamanos makes the point that a lot of people are making critical decisions that are not science-based. They make decisions based on things they believe rather than proven facts.

“Yes, we need to better understand the biology, but everyone’s gone into this craziness with the soil health. Now people say the salt in the fertilizer is killing the microbes. That’s nonsense. We did some studies at Lethbridge with the soil microbiologist there, applying anhydrous ammonia. The conclusion was that the anhydrous did not change the microbial populations.

“Another study in the States showed that the microbial populations were actually higher three days following an application of anhydrous ammonia, except for the fungi. Their populations were lower. I joked with people that here we have a new fungicide.”

John Heard — Heard said he’s skeptical of many of the new in-field tests coming to market. “Are these tests really something I need or just a bad joke that somebody in Silicon Valley dreamed up,” asked Heard.

He said the only real value is if a test gives you information to make an economic decision. The only real purpose for real-time information is when you’re going to vary your nitrogen on the go. But it’s only relevant for nitrogen because we don’t variable rate other nutrients in-field in real time.

“What value is an organic matter test on the Prairies where we have some years like 2016 when we were moist and warm, and we had a huge release of nitrogen from organic matter. And then we have two years of drought.

“How can your organic matter test help predict what the nitrogen release will be when Mother Nature holds those cards? It is the Holy Grail of testing. But probably the devices closer to estimating (nitrogen release) for us are those that also measure real-time weather, moisture and temperature, and whether we’re getting too much water, which causes (nitrogen) losses or just enough water to cause mineralization. And it’s all out of our control.

“Microbial biomass is nice to know, but it’s also nice to know that there’s the same biomass per acre in the soil as having two beef cows per acre. Having 2,600 pounds of biomass per acre is like having two beef cows per acre.”

Don Flaten — Devices such as the Green Seeker, which measure activity in plants have been around long enough to be accepted as valid and useful, said Flaten.

“I’d say the more recent phenomenon is the instrumentation for measuring soil characteristics. The challenge is to make sure the characteristics are measured properly with respect to the questions you’re trying to answer. There’s huge potential for these technologies, but we’re at the pioneering stage right now and many of these devices are lacking in one way or another.

“Here’s an example. We might have an instrument that measures the total amount of a certain nutrient in the soil, but it might not measure the portion of that nutrient available to a crop. Other instruments might measure quite intensively at one certain spot in your field continuously over time, but they don’t account for variability within the field.

“There are several new tests looking at microbial activity, some of which are supposed to predict nutrient requirements. But here’s the thing. Microbial activity might be tying up nutrients or microbial activity might be releasing nutrients. These are some of the details farmers and agronomists need to understand. These devices have a lot of potential once they’re calibrated and validated against conventional soil test techniques. But there are all sorts of issues to sort out with respect to soil characterization. It’s still a buyer beware scenario.”

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Comments

  • neil

    Excellent article. I am interested in this new soil health topic and how the biology of the soil is doing with my management. Its great to have four respected soil fertility experts/researchers give some good advice on how to approach these new soil tests.

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