Soil Testing for Better Warm-Season Forage Yields in Missouri

By Blake Jackson

University of Missouri Extension agronomist Rudra Baral emphasizes the importance of soil testing and precise fertilization for optimal warm-season forage production in Missouri.

The new publication provides guidelines to help farmers achieve healthier pastures and better yields.

Baral stresses that "maintaining healthy forage for livestock requires understanding the specific needs of soil and grass." He recommends soil testing every three years to avoid unnecessary fertilizer applications, which benefits both the environment and farm budgets. "Soil testing is nonnegotiable," says Baral, "Soil Testing and Fertilizer Management Strategies for Warm-Season Forage in Missouri."

Soil pH is a critical factor in nutrient availability, with most warm-season forages thriving in a pH range of 6 to 6.5. Low pH can limit nitrogen availability and bind phosphorus, while high pH can lead to nitrogen loss and reduced phosphorus uptake.

"Understanding soil needs and carefully managing fertilizers is the first step toward achieving healthier pastures, higher yields and better forage quality," Baral explains.

Baral advises farmers to consider soil temperature, growth stage, and calendar dates when applying fertilizer.

In Missouri, the ideal application period is from April to June. Applying fertilizer too early can promote weed growth and prevent forages from adequately absorbing nutrients.

Warm-season annual grasses, such as sorghum-Sudan, millet, and crabgrass, begin growth when soil temperatures reach 60°F at a 4-inch depth. Native warm-season grasses should reach 10-16 inches in height before fertilization.

Baral recommends a split application of nitrogen fertilizer, applying 50% at spring green-up and the remaining 50% midsummer.

Baral cautions against applying fertilizer after July to allow grasses to enter dormancy and avoid winter damage.

For further assistance with soil testing and fertilizer management, farmers are encouraged to contact their local MU Extension agronomist. Some county offices offer soil testing equipment for loan.

Photo Credit: gettyimages-diane-kuhl