Turfgrass is the name given to any of the various grasses grown to form turf. The United States National Arboretum lists bluegrass, fescue, ryegrass, buffalograss, zoysiagrass, Bermudagrass and bentgrass as varieties of grass falling under the turfgrass classification. Preparing soil for a turfgrass installation is a long process, but relatively simple to perform and absolutely crucial to the long-term success of the lawn. The consistency, grading and chemical make-up of the soil are all vital elements to consider.
Perform a soil test on the existing yard. Soil test kits can be purchased at garden supply stores or obtained at most local cooperative extension offices. Follow the directions provided with the test kit. Most need to be mailed to a laboratory for analysis.
Kill any weeds or existing grass if the soil is being prepared for a completely new lawn installation. Sodding.com recommends using a glyphosate type of herbicide. Wait until the herbicide dissipates to continue working the soil.
Till the existing soil, removing all foreign material as you work. Wright Turf Farms recommends the removal of all foreign bodies greater than 2 inches in diameter. The University of Rhode Island Landscape Horticulture Program suggests adding organic materials such as peat into heavy or clay soil types.
Rake the soil to achieve a rough grade sloping away from any buildings and free of any large bumps or holes. Grading regulations vary -- check with local government officials prior to altering the landscape's grade.
Add any soil amendments suggested by the soil test results. The University of Massachusetts Amherst Department of Plant and Soil Sciences says turfgrass grows best in soil with a slightly acidic pH level of 6 to 7. Wright Turf suggests lime to improve soils with a pH of less than 6, and sulphur to lower the alkalinity of soils with a pH level higher than 8.
Layer new topsoil over the existing soil and till the yard again. According to Wright Turf, the ideal topsoil is loam, sandy loam or loamy sand with a final topsoil depth of 10 to 15 inches.
Rake fertiliser into the top 3 to 4 inches of top soil. Maintain the soil's grading level as you rake.
Smooth the soil with a lawn roller. Water the soil with a light spray setting to avoid altering the grade of the soil.
The UMass Amherst Department of Plant and Soil Sciences suggests using a fertiliser with 1.36kg. of nitrogen per 1,000 square feet of coverage for turfgrass. The fertiliser should also incorporate moderate amounts of phosphorus, labelled "P" on most bags, and potassium, labelled "K." Choose fertilisers containing potassium sulphate over fertilisers with potassium chloride, which is more apt to burn grass if over-applied.