Soil mapping is a task many growers want to tick off their list in the off-season, but getting accurate data can be time-consuming and prohibitively expensive. Now, row crop managers have a new option to build soil zones using the industry's most precise and reliable aerial imagery.
There are a host of reasons growers invest in soil mapping—from establishing better variable rate application zones, to interpreting yield maps and planning drainage improvements.
Traditional grid sampling is straightforward, but it’s expensive for an approach that won’t always produce an accurate reflection of soil texture variations in the field. And while SSURGO maps can provide a good starting point, they don't provide the level of detail that most operations need to fine-tune management decisions.
There may actually be significant variability in soil type within a single SURRGO map zone.
For that reason, some growers turn to specialized equipment for electrical conductivity (EC) or electromagnetic (EM) mapping. While effective for some operations, for others this ground-level approach is too expensive and too vulnerable to data anomalies produced by variable conditions or improperly gathered data.
Soil maps created from aerial imagery provide a cost-effective alternative for those growers who haven't yet found a practical path to detailed soil data. Ceres Imaging customers who've requested color infrared imagery of bare soil can use the zone creation tool to create soil maps more detailed than SSURGO options, more affordably than through EC testing
Soil types represented by Ceres Imaging's zone creation tool.
Color infrared imagery incorporates green, red, and near infrared spectral bands. As with any other approach to soil mapping, optimal timing can depend on soil type and moisture content—but Ceres Imaging remote sensing scientist Kirk Stueve, PhD, has some general advice.
“Less residue is better,” Stueve says. “Ideally, you’d have 20% or less residue, consistently distributed on the field.” To achieve this, Stueve recommends capturing imagery on bare soil 10-14 days after tillage, with rain or irrigation within a week of that tillage.
For more tips, or to schedule a consultation, contact your Ceres Imaging representative.