Lime has a few very important uses in soil preparation. Because it promotes alkalinity through a chemical process, lime is used in gardening to balance soil for planting. Construction crews use lime to suck the moisture out of soil and stabilize it for building. Pouring concrete on unstable or wet soil can lead to problems with the concrete setting, and future problems with the stability of the concrete. Remove any moisture to keep your concrete from cracking or being displaced in the future. If you're pouring concrete for yourself, take a reading of your soil -- if there's standing water, or if the soil is obviously moist to the touch, there's a good chance you'll need to suck the moisture out before you start. Regardless of the reason, liming soil is always done in the same way.
Determine how much lime you need according to manufacturer directions. A standard guideline for deciding on the quantity of lime is that sandy soil will need less lime than clay, which has a high moisture content. Every lime powder is the same when it comes to drying soil, so don't worry about deciding on a specific brand of lime. If you're in doubt about how much lime to use or what kind of soil you're working with, take a sample to an expert. Employees at home and garden shops are always available to help with home improvement projects like pouring concrete or amending soil for a construction project.
Pour lime into the spreader wearing goggles and gloves and apply the lime to your soil. This is best done before you plant or start your construction process; amending the soil before you start will bring better success. If you've already poured concrete, there is no way to amend the soil underneath. If you have established plants or grass, use lime only if those plants need additional alkalinity. Many plants have a natural preference for acid rather than alkaline substances. For this reason, it's better to use lime on unplanted ground rather than soil that has plants and/or grass already planted.
Use the shovel to turn the soil over and mix the lime in for quicker results. This is not absolutely necessary. Lime will begin to remove moisture from the soil almost immediately through a chemical process. If you're going to be pouring concrete, give the lime two to three days to do its job before progressing. After two to three days, if the soil is still quite moist, consider adding a second layer of lime. Keep in mind that lime will make concrete set faster, and try not to expose the concrete to any of the lime powder as that will make your job more difficult.