Chris Parker has walked a lot of pasture and hay fields in his some 27 years as the Morgan County Extension Ag Educator. Ask him how you could improve your pasture and he is quick to answer.
"The key to helping pastures be more productive is to soil test them regularly," he insists. "You will often find that the pH level is low. The field needs lime. The key to taking advantage of other nutrients, like P and K, is to have the pH at the proper level."
Grasses don't need to be as high as alfalfa, where the recommendation is often for a ph of around 7.0/. However, pH levels below 6.0 don't cut it even for grass, he says. If pastures haven't been tested in a while, it's possible that the pH level could be lower than you think.
There are no special requirements for pulling spoil tests on pastures, he notes. Follow the same procedures you would follow if you were pulling soil tests for corn or soybeans. He typically pulls cores at about a depth of 6 inches. He looks for bare spots, and makes sure he doesn't get grass material in the sample. As when testing for corn and soybeans, it takes a dozen or more cores to make up one good sample. If the pasture is rolling and features several soil types, of adequate size to justify treating them differently, then you will want to sample those soil types separately, he says.
The big thing about pulling cores is to be consistent, going to the same depth each time, he notes. Some people, especially soil consultants who pull soil samples for a label, will mark their probe with black tape or even a nail scratch so they know the exact depth to sample each time.
If the pH is low, you can spread the lime on top. It won't hurt livestock that will graze there, he notes. Allow for 6 months to a year for the effect to take hold. Since no tillage is involved, the change will happened slower than in a crop field where you apply lime and then till it into the soil.
Your biggest challenge may be finding someone willing to spread lime on your pasture if you only have a few acres.