It’s a sermon the Extension Service has preached for years, but with fertilizer prices at a near record high, the admonition to base fertilization on soil tests should bring new converts into the fold.

“Soil testing is one of the cheapest practices a forage producer can use,” said Texas AgriLife Extension forage specialist Vanessa Corriher, speaking at the annual Ag Technology Conference on the Texas A&M-Commerce campus.

“For the past few years, fertilizer prices have increased significantly and have not come down much,” Corriher said.”So producers must learn to manage cost and maintain optimum production.”

Fertility recommendations should be based on how much nitrogen, phosphorus and potassium, as well as secondary and micronutrients are available in the soil. “If you don’t know what nutrients you need and at what rate, you either waste money or lose production.”

A $12 bargain

Producers should set production goals for hay production or grazing and fertilize accordingly. “Without soil test recommendations, it’s just a guessing game. At $12 per sample, soil testing is a bargain.”

She recommends annual testing for hay production. “Taking hay off removes nutrients and changes the soil environment every time you cut and bale.”

For pastures, she said testing every two or three years should be adequate and that recommendations will consider credits for nutrients already available. “Cattle recycle nutrients with feces and urine in pastures. Nutrient recycling is less in hay meadows.”

Producers should take a standard sample, from 0 to 6 inches deep, for nitrogen, phosphorus and potassium. They might also want a deeper sample to detect nutrients at 12, 18 or 24 inches. She said secondary nutrients—calcium, magnesium and sulfur—are also important, along with micronutrients—copper, iron, manganese and zinc.