What is in this article?:
- New Ways to Evaluate Soil
- Soil sampling
Soil quality is the most important base layer for all farm production decisions. That includes decisions about yield goals, plant populations, fertility programs and hybrid genetics, says Clay Mitchell, a Harvard-educated corn and soybean grower, futurist and new technology guru from Buckingham, IA.
In the past, farmers and landowners have tended to base both their management decisions and farmland sales on soil surveys that are at least a generation old, but now that’s changing rapidly, he says.
"There is no other physical asset that trades on its condition from a long, long time ago," says Mitchell. "In a modern farming paradigm, agriculture will require higher resolution analysis of soil capacity to effectively index farmland values and to determine what it is that we're buying after all."
New, analytical techniques to measure soil quality, nutrient content, texture and, ultimately, productive capacity will soon help to support land investment premiums and more productive, sustainable farm-management decisions, he says. "With recent technological advancements in soil analysis, we can measure nutrient content and physical properties of soil in ways that we haven't been able to before," says Mitchell. "This includes both how soil samples are collected and how those samples are prepared and analyzed."
Determining the nutrient profile in the rooting zone, typically considered to be at least 4 ft. deep, is the best place to start when evaluating a new farm's production potential, Mitchell advises. "You want to look for the depth at which nutrient levels change," he says.
Soil probes can easily mount on a pickup and take samples as deep as 4 ft., he says. "Using this technology is a way to inventory soil productivity of farms for resale value for buying and selling farmland," Mitchell says.
Deep soil samples are important for land sales, but most management decisions can be made with shallower sampling, he adds. "Shallow sampling can be fine as long as people are consistent with depth when making year-to-year comparisons and aware of the depth at which their soil fertility changes," says Mitchell. "Then the shallow sampling can work for annual sales."
Still, the marketplace is eager for even more accurate ways to factor soil-nutrient levels and stewardship into farm leases, he adds. "There is increasing professionalism falling into place affecting how leases are written for farm-investment groups," Mitchell says. "However, certain protocols need to be followed if specific soil-nutrient expectations are written into a lease."
If a farmer fails to maintain soil nutrient levels, landowners would like to be able to hold the farmer liable, and that is what drives the demand to specify soil-fertility levels in a farmland lease, explains Mitchell.
"At nearly $100/acre for fertilizer replacement levels on high-productivity grain farms, the fertilizer cost is between 20% and 40% of annual rent," he says. "A farmer who mines the soil is effectively lowering the returns to the landowner by that amount. Furthermore, if the farmer adds to soil erosion, soil fertility is lost in a way that wouldn’t be accounted for if the lease simply required application records."