Once it's all turned in, you can immediately replant with a crop. Add Compost Of course, using compost is another very effective way to improve the soil. In Missouri, clay rules, says Denny Schrock, and the best thing you can do is add organic matter. If you work in a good amount in the spring, it will improve the soil structure when you're planting. It's important to use only finished, completely decomposed, compost in spring.
Every little bit helps.
But it is possible to add too much organic matter, especially to clay soil. So, as a rule of thumb, Schrock says don't add more than a third of the volume of the soil at any one time. For example if you're going to work the soil to 6 inches deep, add a 3-inch layer of organic matter, and work it in thoroughly. Failing that, you can use any tool, from a spade to a tiller. Raise the Beds, Dig the Soil Working amendments into the soil offers a good opportunity to build raised beds.