For many crop farmers the knee-jerk, somewhat tongue-in-cheek response might be, “Are you kidding? I already have — have you seen what’s going on with input costs and crop prices lately?”
Humor aside, there’s reason to question whether your soil health is also impacting your bottom-line farm profitability more than you realize, according to Pioneer Field Agronomist Gary Brinkman.
While the traditional mindset and focus of soil health is on the big three in soil fertility — Nitrogen, Phosphorus, and Potassium (NPK) —as well as pH levels, Brinkman told producers during the recent Michigan Farm Bureau Growing Together conference that a paradigm shift is underway.
And given the bleak economic outlook for 2019 crop budgets, re-thinking soil health management on a holistic approach could help the pocketbook by identifying current fertility practices that might be causing unneeded over-application and higher costs.
“Soil health has taken on a new meaning, but it’s basically trying to measure overall soil or yield productivity to maximize soil health and performance,” Brinkman explained. “Soil health looks at things such as chemical aspects, physical aspects, and most recently, the biological aspects of the soil that are indicators to improve productivity.”
According to Brinkman, physical trait examples would include infiltration rate, bulk density and compaction.
“Those are things that we have measured in the past,” he said. “It's not uncommon that I'm trying to measure the ability of the penetrometer to penetrate into the soil to see whether or not there are compaction zones.”
Chemical aspects of soil health is where the traditional testing has focused, including soil tests for pH, phosphorus, potassium, nitrogen, and more recently micronutrients. “Those are all very important indicators of whether or not I'll have healthy soils as measured by crop productivity,” Brinkman said.
Biological aspects — the third component of soil health — is, in many cases, the “new frontier,” according to Brinkman, who adds that “there's a lot of unknowns.”
“We're looking at how to measures soil health through biological traits such as carbon mineralization and that's basically a measure of soil respiration,” Brinkman added. “If we think about our own health, we have to be breathing to be alive and healthy. Well, we're finding that the soil actually has a similar capacity — it breathes and requires components to give its breath.”
According to Brinkman, several new tests have been developed to measure carbon dioxide generated through microbial activity by living roots, which also give off carbon as part of normal plant growth.
“In the same way we're expelling carbon, plants are expelling carbon,” he said. “Measuring soil carbon gives us an opportunity to measure, in a new way, a different dimension of our soil health.”
Several of those new tests come with fancy names and a pretty hefty price tag compared to normal soil tests.
The Solvita test, for example, measures carbon emission to calculate biological activity will run $60 per test. The Haney Test, which combines five measurements into one score to determine carbon to nitrogen ratios, will fetch $50 per test. And the Cornell Comprehensive Assessment which checks 12 different soil measurements will range anywhere from $60 to $170 per test.
“It’s one of the problems we’re running into — it’s not inexpensive,” Brinkman said.
Cotton Underwear — a less expensive option…
So back to the soil-your-undies proposition.
For producers who want to get a relatively cheap assessment of their current overall soil health, Brinkman shared a simple project he conducted at the Pioneer Research Farm in Johnston, Iowa, using six pairs of cotton underwear — three white, three blue-colored.
A pair of the blue and white briefs were buried four inches deep, side-by-side, in three different fields with different crop rotations — corn after corn; corn after beans; and a nearby grass waterway.
Brinkman left the elastic bands just above surface level so he could find and retrieve them three months later.
“We came back three months later and measured the degradation of the decomposition of that pair of undies and it was a remarkable demonstration of biological activity and it was interesting to see the difference between the white undies and the blue undies,” Brinkman said. “There was something about the blue dye undies that, with less biodiversity, just did not break down as well as they did where I had corn following soybeans.”
According to Brinkman, the blue undies buried on the continuous corn plot were fairly intact, while the pair buried in the corn after soybean plot were much more degraded due to higher microbial activity. He was also surprised the grass waterway undies weren’t more degraded, but he suspects a prolonged drought impacted the results due to frequent mowing.
“It's a great demonstration anyone can do, especially if you're going to have a crop tour,” Brinkman suggested. “If you plan ahead and place some of these in a couple different cropping environments, you’ll get a first-hand view of microbial activity. It's interesting to see how even just subtle changes, like blue dye versus no dye, can make a difference in degradation and microbial activity.”
Factors Driving Soil Health Interest
Like it or not, consumers are driving the train on soil health, said Brinkman, citing a General Mills 2015 survey of consumer preference for regenerative agriculture and their concerns about air and water pollution. A repeat of the consumer survey in 2018 showed the importance consumers placed on those environmental concerns jumped 30 points in the three-year period.
“The consumer is much more engaged in where they're getting their food and how it’s grown,” Brinkman said. “As a result, food companies like Walmart, General Mills and others are looking and listening to the consumer and saying, ‘OK then, I better get the food that I'm sourcing from growers that are going to be more sustainable.’”
Brinkman forecasts the momentum will continue building with more major food companies starting to get involved in measuring soil health and being cognizant of how a crop’s grown. General Mills, for example, established a team of soil scientist to focus on regenerative agriculture — and improve soil health as a consumer would see it.
“Food companies like General Mills, Walmart have set some pretty lofty goals in my opinion as to how they want to start to impact soil health, including bringing about a greater carbon sequestration of carbon dioxide to lowering greenhouse gases,” Brinkman said. “They view soil as a great pool for capturing greenhouse gasses through the photosynthesis process: capturing carbon dioxide through a living plant and putting it back into the soil through residue and building organic matter.”
Will heavy hitters in the food industry such as Walmart, the low price leader, and ultimately consumers be willing to back up their preferences for regenerative ag practices at the check-out line with a higher price tag?
“That's a great question,” Brinkman said, noting the irony of another consistent guiding principle of regenerative agriculture which calls for integrating livestock back into farm operations.
“I almost have to laugh because a lot of consumers are almost to the point where they are minimizing their intake of beef and other meats,” Brinkman said. “To make this series of principles work, one of the key components is the integration of livestock. So I think the food industry will have challenges trying to please consumers.”
Farmers will face their own challenges trying to balance improved soil health and productivity, while also remaining profitable. Beyond improved crop rotation, no-till and minimum tillage practices, Brinkman said he’s seeing renewed interest in the use of cover crops, which has gone full circle during his career.
“As a farmer, there is good reason to consider management practices that improve your soil health and be a good steward,” Brinkman concluded. So go ahead and take the challenge - soil your undies. You might be surprised at what you’ll learn!