Spade or rototill the top 4 to 6 inches of soil. This not only helps relieve compaction, but also incorporates the compost and other organic matter into the soil. Avoid deeper cultivation, which causes more moisture to be lost from the sub-soil. Use a spading fork to break up hard ground, then follow with a tiller to incorporate the organic matter. Excessive rototilling, however, destroys the soil structure, resulting in poor drainage and surface crusting.
Crusted soil makes it difficult for seedlings to emerge.
Once the soil is prepared and you are ready to plant, check soil moisture content again. If it is extremely dry, irrigate lightly a day or two before planting. Plant seeds in shallow trenches to conserve moisture. Cover the seeds about twice as deep as you would during spring planting to keep seeds from drying during germination. Light irrigation 2-3 times per day during extremely hot weather will keep the soil moist and prevent seed death.