Clover Sowing

I have a pecan orchard and would like to attract more beneficials to help control unwanted pests. I also read that clover helps put nitrogen in the soil.
What is the preferred method of sowing clover and what recommendations do you have to ensure a successful crop?

Direct sowing is best. Cultivate, then seed at the rate of 9 to 12 kg per hectare. Sow just before a rain is expected in either early spring or early fall. Plant seed in drills about an inch (2cm) deep.

Do you have any other recommendations to help manage pests in the orchard, improve soil quality, and for a good fertilizer?

Planting nectar bearing plants helps keep beneficials in the area. Clover is a good start. Introducing releases of beneficials from commercial growers of these insects is also a good idea. Sources closest to you can be found on the Internet. Richters still sells Scanmask (Richters catalogue #T2600), the predatory nematodes that attack insects pupating in the soil.
Working compost into the soil every year or top dressing under the crown of trees with it is a very beneficial way to fertilize. If you are on thick clay working sharp builders sand into the soil is essential. Mulching under the crowns keeps soil temperatures more even and conserves moisture, all important functions in these times of global warming and the resulting erratic climate.