Depending on the species in your seeding, it may be of benefit. No fertilization should be done on native plantings. In most cases, any fertilizer benefits the annual weeds more than it does the native species. This is the toughest part. During the first year, the prairie seeding may not look like much more than a weed patch.
Most native plants put most of their growth into their root system the first year.
Also, many of us are not great at identifying native plant seedlings. In late summer, have someone with native prairie experience look at the seeding with you. They can help evaluate seeding success and show you what different species look like. In the second and third year you should start to see the native species come shining through. Country living may offer wonderful sunsets, songbirds, and a different pace, but don t be lulled into a false sense of security.