Proper lime application benefits hay production

STARKVILLE, Miss. -- Mississippi is a significant player in the nation’s beef cattle production, and to do that efficiently requires a lot of land managed as pastures and for hay production.

Brandi Karisch, Extension beef specialist, said the amount of hay and forage needed for a beef herd depends on the nutritive value of the forage and the size of the livestock eating it.

“A general rule of thumb is that a cow will eat around 2.5% of her body weight in dry matter per day,” Karisch said. “For example, a 1,200-pound cow will eat approximately 30 to 33 pounds of hay each day. Growing pasture contains a lot more moisture than dry hay, so that same size cow may eat 40 pounds of growing forage in a day.”

She said stocking rate recommendations, or the number of cows per acre, depend heavily on animal and forage type, as well as soil fertility.

“In general, I would recommend an average of 3 acres per cow throughout the year for mature cows in Mississippi,” Karisch said. “During drought, this rate needs to be increased, but during good conditions, this could be decreased.”

Rocky Lemus, forage specialist with the Mississippi State University Extension Service, said in the Southeast, one of the biggest limiting factors in forage production is soil pH.

“Liming becomes a critical management practice to neutralize soil acidity, enhance nutrient availability and boost forage productivity,” Lemus said. “Liming must be the first target of any fertility program before any other nutrients are added to the system.”

A soil test is used to determine the exact pH of the soil and to determine the existing amounts of nutrients.

“Achieving an ideal pH range of 6.0 to 6.5 can improve fertilizer efficiency by up to 70%,” Lemus said. “As soil pH drops below 6.0, key nutrients such as nitrogen, phosphorus and potassium become less available to the plant.”

Lemus said having the wrong soil pH causes plants to be unable to use nutrients efficiently. When every dollar counts and profit margins are slim, efficiency matters.

“While lime is the first step in developing a fertilization and nutrient management plan, the economic return can vary based on soil type and existing pH levels,” Lemus said. “Despite this variation, lime can enhance productivity and provide a higher return on investment.”

Lemus said a lower soil pH leads to much higher fertilizer needs and therefore a higher cost of production as the plants growing in the soil cannot efficiently use the supplied fertilizer when the pH is wrong.

For example, a pasture with a 4.5 pH loses $180 in the combined amounts of nitrogen, phosphorus and potassium, while a field with a pH of 6.0 loses just $41 an acre in fertilizer.

“In these challenging economic times with increasing input costs, beef and hay producers must rethink their nutrient management strategies,” he said. “Rethinking the approach to soil sampling and how to use liming must be the first step towards good economic decisions related to fertilization.

“Neglecting to properly lime hay fields and pastures causes a significant decline in profitability due to drastically reduced forage yields, wasted fertilizer and degraded forage nutritive value,” Lemus said. “Livestock producers need to take new approaches based on their location, the resources available and the type of operation.

“If you can only afford lime or fertilizer but not both, apply the lime,” he said.

Learn more about proper nutrition management for pastures and hay production at https://extension.msstate.edu/agriculture/forages.