Timing fertilization of winter pastures proving tricky amid drought, above-average temperatures

Source: AgriLife Today
Fertilizing to produce quality winter annual forages, such as ryegrass or small grains, has been difficult for East Texas producers to time as above-average temperatures and moderate drought continue, said Dr. Vanessa Corriher-Olson, Texas A&M AgriLife Extension Service forage specialist, Overton.
Corriher-Olson has received many calls from producers recently regarding the best time to fertilize, especially with nitrogen. They want to know if it’s best to fertilize before or after rains.
Other nutrients like phosphorous and potassium can be applied when winter grasses are planted, but Corriher-Olson said producers should be mindful about when they apply nitrogen.
She recommends fertilizing prior to a forecasted rainfall, but said it has been difficult this year for producers to gauge whether precipitation will materialize.
“The best scenario is to fertilize and then get moisture,” she said. “Producers watch the forecast before an application but the issue this year is that the forecast a week out may call for a 60 percent chance of rain, then the chance of rain diminishes and it may not happen.”
Much of East Texas is experiencing moderate drought, she said. Above-average temperatures compound the problem because warm-season grasses like Bermuda grass have not gone dormant.
She said producers typically plant winter pastures in late September or early October but that many planted in August hoping to capitalize on late-summer rains. But cool temperatures have not arrived.
In East Texas, fertilizer is typically applied in mid-November, around the time of the first frost as lower temperatures begin to induce dormancy of warm-season forages. Fertilizing near or after the first freeze ensures winter grasses are not competing with Bermuda grass for nitrogen.
“During an average year we have the first frost around Nov. 15 in East Texas, but this year it’s past that point and Bermuda grass is still potentially growing because temperatures are still in the 80s. If there was moisture it would definitely still be growing, and you don’t want your warm-season grasses using the nitrogen you applied for fall and winter forages.”
Corriher-Olson said the most important aspect of fertilizing for forage production is soil testing, which identifies the soil pH and nutrients, such as nitrogen, phosphorous and potassium, that might be deficient for optimum forage production.
Another consideration is the timeframe producers want pastures ready for grazing or forage, she said. Pastures require a fertilizer application for fall and early winter forage production and another for spring growth.
The amount of fertilizer applied depends on soil test recommendations and how much production producers hope to achieve, stocking rates and expected rainfall, she said.
“Fertilization can be a major cost in winter pasture production and should be done based on soil test recommendations and with moisture, if we are so lucky,” she said.