Soil testing is an efficient tool for farmers to maximize yield potential and profitability. For many farmers, soil testing is a useful and relatively inexpensive management tool to assess crop nutrient levels in their fields. Proper methods and timing of soil sampling help ensure reliability of test results for making informed decisions related to soil inputs such as fertilizer and lime.
“When conducting soil tests, we hope to check soil health and soil microbiological activity,” said Paul Yoder, Pioneer Field Agronomist. “We take into consideration management practices and soil types, and how those microbiologicals behave. Combining soil testing with tissue sampling, soil properties and growing conditions gives us a more complete picture of overall soil health and how to maximize yield.”
Regardless of if the sampling plan is random or part of a precision management system, collecting and submitting a clean and representative sample is required for reliable results. It is recommended to sample every two to four years for a given field.
Critical nutrient levels are the point where yield loss potential increases quickly if soil test levels for a particular nutrient fall below that threshold. Establishing those levels through soil testing can help farmers maximize yield potential.
One strategy is to build nutrient levels just above the critical levels and apply nutrients to annual or biennial crop removal rates. This accounts for variability in fertilizer spreading and anticipated crop removal. This practice may guide appropriate fertilizer rates for rented land or when fertilizer prices are high while still reducing the risk of yield loss.