Limestone Application Guidelines
Limestone may be applied at any time of the year, although fall application is generally considered optimum. Aerating the lawn immediately before or after applying limestone increases its effectiveness. This is especially helpful when application rates exceed 50 lbs/1000 square feet. Use a high quality ground or pelletized agricultural limestone product to meet the limestone recommendation on this report. Manufacturers of agricultural limestone products provide a number called the calcium carbonate equivalent, or CCE, on the label. CCEs with high numerical values (close to 100% or above) indicate a pure limestone source (greater ability to neutralize soil acidity). The amount of limestone recommended on this report is based on an agricultural ground limestone with a CCE of 100%. If your limestone source is close to or equal to 100%, you don't need to adjust the recommended amount. In the event that you use a limestone source with a CCE well below or above 100, use the following formula to adjust the required amount.
Actual liming material required= ((Soil test recommendation in lbs/1000 square feet) x 100) ÷ CCE of liming material
Example:
Soil Test Recommendation: Apply 75 lbs limestone/1000 square feet
CCE on label: 80%
Actual liming material required = ((75 lbs) x 100) ÷ 80 = 94 lb/1000 square feet of actual liming material
Turfgrass Fertilizer Grades
Turfgrass fertilizers contain one or more plant nutrients. The most common nutrient in lawn maintenance fertilizers is nitrogen, but some products also contain phosphorus (designated on labels as available phosphate, or P2O5), and/or potassium (designated as water soluble potash, or K2O). The amounts of these three nutrients are listed on the fertilizer container as three numbers, indicating the percentages by weight of nitrogen, phosphate, and potash—always in that order. The three numbers are referred to as the fertilizer grade or analysis. For example, a 50-lb bag of fertilizer with a grade of 30-0-10 contains 15 lb of nitrogen, no phosphate, and 5 lb of potash. A 10-lb bag of the same product would yield 3 lb nitrogen, no phosphate, and 1 lb of potash. Knowing the fertilizer grade is important in determining which nutrients, and the amount of each nutrient, are contained in your fertilizer. The majority of lawn maintenance fertilizers are now free of phosphorus, so if your soil test report indicates a need for phosphorus, you can apply a starter fertilizer. Starter fertilizers always contain P2O5 and usually some K2O as well.
Get the Most Out of Your Fertilizer While Protecting Water Resources
The following are suggestions for maximizing the efficiency of your fertilizer program, while minimizing nutrient losses to water resources through leaching and runoff.
- Apply nitrogen, phosphorus, potassium, and limestone according to soil test recommendations. Do not apply more than is needed as this may harm the turf and contribute to leaching and runoff.
- On turf, apply fertilizer in two or three applications over the growing season so as to meet the needs of your turf at the appropriate time of year (mid to late spring, late summer, and late fall). Late fall fertilizer applications should take place around the same time as the last mowing of the season, and before soils freeze. An alternative to late fall fertilization is an early spring fertilizer application.
- When possible, use fertilizer containing some nitrogen in a slowly available form, as either water insoluble nitrogen (WIN), controlled-release nitrogen (CRN), or coated urea. This information is provided on the fertilizer label.
- Returning clippings to lawns can cut nitrogen fertilizer use by up to one-third.
- Keep fertilizer on the lawn and not on pavement. Shut off your spreader when moving across driveways or maintenance roads, and blow or sweep granules from pavement onto the turf. In small lawns enclosed by sidewalks and driveways, use a drop spreader for greater accuracy.
- Do not apply fertilizer to lawns under summer dormancy or on frozen surfaces in winter.
- Fill and empty fertilizer spreaders in an area where spills can be easily cleaned up. Use your spilled fertilizer; don't wash it into the street or storm sewers.
Ag Analytical Services Lab
Hours: Monday-Friday, 8:00 AM - 4:00 PM
- Email aaslab@psu.edu
- Office 814-863-0841
- Fax 814-863-4540
Ag Analytical Services Lab
Hours: Monday-Friday, 8:00 AM - 4:00 PM
- Email aaslab@psu.edu
- Office 814-863-0841
- Fax 814-863-4540