Choose What to Measure
Putting Data to Work
Scientists recently announced the discovery of a new phylum of microbes found deep below the Earth’s surface (think the bottom of a seven-story building below ground). Soil testing kits might not measure 70 feet below the surface, but there are plenty of living organisms sharing the soil with crop roots. Soil testing kits can help growers understand what their crops are lacking.
Whether it’s soil compaction, evaluating nutrient loads, moisture levels, or any other number of factors necessary for healthy plants, soil testing is a critical tool.
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Testing to understand the impact of soil compaction in the field can help growers make better soil health decisions.
Photo by Josh Jeske / Terraform Tillage
There are many different versions of soil tests growers can choose from depending on just what they are looking to measure.
“The Haney test looks at some of the things that people are more familiar with, such as inorganic fertility, macronutrients, NPK, and micronutrients, and their plant availability,” says Soil Scientist Liz Haney, Co-owner of Soil Regen and Co-Developer of the Haney Soil Health Test.
This test, however, goes beyond the makeup of traditional tests, also exploring soil biology, including microbial respiration — how active microbes are in the soil — as well as their food source, which is water-extractable organic carbon.
“As far as some of the differentiating factors, we look at water-soluble organic nitrogen which is plant available and can also be mineralized into inorganic nitrogen,” Haney says. “So, we look at a lot of different aspects that standard soil testing doesn't look at, especially if you're in a biological system.”
According to fifth-generation farmer Josh Jeske, Founder of Terraform Tillage, traditional soil testing hasn’t changed much in the past few years, but methods have evolved significantly “to efficiently measure and manage the soil’s physical properties, specifically compaction,” he says. “Before developing our SmartProbe system, conducting detailed soil compaction analyses was uncommon and typically seen as impractical.
“Our technology,” Jeske continues, “has made it straightforward and cost-effective for farmers, agronomists, and retailers to identify exactly where compaction is limiting yields, enabling targeted subsoiling efforts or other compaction management products only where they’re needed and reducing unnecessary expenses in areas that won't benefit agronomically or environmentally.”
“Growers want to know what's available as far as nutrients go. We don't want to over fertilize or under fertilize.”
For growers concerned about soil compaction, Jeske suggests growers start with that spot where they generally enter and exit their fields.
“I recommend that growers initially conduct a soil compaction survey to establish a baseline for their fields’ soil structure,” he says. “This baseline can reveal hidden yield limitations unrelated to fertility. Unlike fertility testing, regular annual soil-compaction testing isn't usually necessary, as compaction patterns often remain consistent unless significant field traffic changes or adverse conditions occur. However, I do recommend additional compaction testing if farmers have been forced to work fields in wet conditions, potentially increasing compaction. In these cases, after establishing a baseline, targeted spot checks on problem areas are typically sufficient, rather than re-testing entire fields.”
With a better understanding of what’s inhibiting growth, end users can save on their crop inputs. But to do that, they need to know what’s in the ground. According to Haney, the average field has 30 pounds of unused nitrogen.
“Growers want to know what's available as far as nutrients go. We don't want to over fertilize or under fertilize,” Haney says. “We want the growers to have the biggest return on investment they possibly can. We use different extractants than a conventional test. But we also look at the biology because biology controls nutrient cycling.
“So, we want to know if your microbes are active, if they're going to be releasing nutrients to the plant. We want to know if the soil is in balance and if it's going to be functioning at its optimal rate,” Haney says.
Testing gives end users the information they need to optimize the soil.
“Once we start balancing out the soil and we can see the effect of these management practices,” Haney says, “we can start seeing a bigger return on investment through improved yields, improved drought, resistance, and reducing herbicide and fungicide passes that will come from your soil being in balance.”
“Efficiently managing soil compaction can significantly boost farm profitability, sustainability, and resilience, especially during challenging weather years.”
Testing, of course, is needed to find that balance.
“We're trying to make decisions from what we're seeing in the data,” says Leo Rivera, Director of Scientific Outreach at METER Group. “Sometimes that means focusing on what's actually happening across field.”
METER provides advanced, cloud-connected, real-time soil-plant-atmospheric data using an extensive array of research-grade soil science instrumentation. That data is used by universities conducting environmental research along with labs, and government agencies.
“There's all sorts of data coming in,” beyond standard precipitation data, Rivera says. “You have wind temperature, relative humidity, and vapor pressure, which is really important for understanding the potential for water loss from crops. There are also models that come in that tell you the evapotranspiration, which is how much water the crop is actually transpiring out.”
The loggers transmit the data through various means of communication, Rivera continues. “Typically, cellular is the most common, and that data is transmitted and stored on a cloud server. Growers can access that data anytime from their phones using an app, or they can go onto their computer and use web-based software. What's cool is you can get your weather data there, and with soil sensors, you can get all your soil data. It's actually pretty powerful to have all that data right there so they can make decisions.”
There’s always some unpredictability when it comes to agriculture. Soil tests give growers, retailers, and crop consultants the information they need to manage the variables they can control.
“The Haney test is a tool to help visualize and see what's going on, and then the rest is really up to the producer,” Haney says. “We'll help walk them through what management practices can improve certain things like increasing soil organic matter or increasing the amount of food source available to the microbes in the soil. Then the return on investment really starts to increase. And it's going to change every year because we don't have any control over climate.”
There will always be parts of the process that growers are unable to control. With the right soil testing tools, however, growers will be better able to manage those parts of the process where they can take action.
“The most important takeaway is that efficiently managing soil compaction can significantly boost farm profitability, sustainability, and resilience, especially during challenging weather years,” says Jeske. “I've seen drastic improvements on our own farm here in central Iowa over the past few years, and our transition away from full conventional tillage has improved our yields, reduced our input costs. and opened up lucrative opportunities in the form of carbon programs.”
Looking to the future, METER’s Rivera expects soil testing will provide even more information than it does now.
“We're always trying to evolve and find ways to make tools that can help people make decisions, but also, to improve their lives by having a better understanding of what's happening in the environment around their plants,” he says. “And a lot of that comes from just working with growers to understand what their needs and what their pains are, and how we can help make that better. We hope to continue to make better tools that will help them quickly and easily make decisions on what's happening with their plants, so they can be more proactive. And, so they can also manage the resources that are becoming less and less available — especially in arid climates.
“We're always continuing to innovate and try and make better tools,” Rivera says. “There's a lot of cool stuff coming down the road.”
