Penn State Releases New Pre-Sidedress Nitrate Test for Corn

Jun 06, 2024

By Robert Meinen

Penn State researchers and Extension have released an updated version of the Pre-sidedress Soil Nitrate Test (PSNT) for corn. The fact sheet is available in electronic form and can be downloaded as a pdf file from this Penn State Extension webpage.

The affordable PSNT is a valuable tool that allows producers to sample soil during corn’s early growth stage and have it tested at a soil laboratory for nitrate nitrogen (NO₃) concentration. The NO₃-N is indicative of the N supply available in the soil from manure and other organic sources. The lab results are entered into a simple PSNT formula that provides a recommendation of sidedress nitrogen amount that is expected to provide Economic Optimum Nitrogen Rate (EONR) to the corn in the current growing season. The test can also indicate if no sidedress N is needed. Both scenarios can prove valuable considering the soil test is relatively inexpensive compared to bulk fertilizer purchases.

The updated PSNT fact sheet contains a new formula that was developed after extensive analysis of data from many field plots that reflect changes in agricultural practices that have occurred since the original PSNT was developed in the 1990s. The new PSNT reflects the widespread use of cover crops, modern manure management, and industry focus on soil health that have helped many soils attain a resilient ability to supply N to crops from existing organic matter.

Another new section of the PSNT fact sheet provides guidance for the collection of soil from fields that have received manure injection. Fields with manure injection have patterned N-concentration variability and the sampling protocol developed from research in Pennsylvania soils takes advantage of the predictable NO₃-N variation to provide a PSNT laboratory result that is reflected in the new PSNT formula.

Soil sampling and laboratory protocols should be followed closely so maximum agronomic, economic, and environmental benefits of the new PSNT can be realized.

Source : psu.edu

Video: Residue Management

Residue Management conservation practice manages the amount, orientation, and distribution of crop and other plant residue on the soil surface year-round while limiting soil-disturbing activities used to grow and harvest crops in systems where the field surface is tilled prior to planting. This video explores how Ryan McKenzie implemented this conservation practice on his farm in Samson, Alabama.

Practice benefits:

• Increases organic matter

• Improves air quality

• Decreases energy costs

• Reduces erosion

• Improves soil health

The Conservation at Work video series was created to increase producer awareness of common conservation practices and was filmed at various locations throughout the country. Because conservation plans are specific to the unique resource needs on each farm and also soil type, weather conditions, etc., these videos were designed to serve as a general guide to the benefits of soil and water conservation and landowners should contact their local USDA office for individual consultation.