Lawn

MSU Extension Soil Web pages for Consumers

11/16/09

Knowing the conditions of your soil is one of the most important factors in growing healthy lawn turf. Congratulations on getting it tested!

Example report: (See below for number and time of applications.)

RECOMMENDATIONS FOR: Lawn, ryegrass
Limestone:	NONE
NUTRIENT NEEDS:
Nitrogen (N)	Phosphate (P₂O₅)	Potassium ( K₂O)
3-5 lb/1000 sq ft	NONE	NONE
FERTILIZER OPTIONS:


MESSAGES
Maximum single nitrogen application is 1lb/1000 sq. ft. Nitrogen rate may be decreased 20 to 40% if clippings are returned. For shaded grass decrease nitrogen rate by 1/2 and apply primarily in fall.

Test methods: 1-1:1 soil:water pH, 2-Bray P1 Extractant, 3- 1N Ammonium Acetate Extractant

Lime: Turf grows well in pH ranging from 5.8 to 8.2. Michigan lawn soils are generally within this range. If lime is recommended, see adding lime.

If you are preparing soil for seeding or sod, see New Turf.

Nitrogen is an essential nutrient for all plant growth and is available in many forms from garden centers or professional lawn care services. To successfully meet the objectives of most lawn areas, annual applications of nitrogen are required. The Recommendations section of the lawn report like the example above gives a range of nitrogen to use. You will decide how many times you apply fertilizer each year. The following factors will determine if you wish to apply fertilizer at the top or bottom of the range...or somewhere in between. Once you have decided your range, Use a fertilizer calculator; enter your recommendation and the fertilizer you want to use, and the calculator will tell you how much to buy and apply, or Learn to calculate the amount of fertilizer that will meet your goals.

Please consider the environmental responsibility of applying nitrogen to your lawn. Nitrogen is easily dissolved in water. When too much nitrogen is available for turfgrass plants to consume and excessive water is present, nitrogen can move away from the lawn and into water resources. This situation can be easily avoided by following these suggestions.

	Do not apply more than 1 pound of nitrogen to 1,000square feet of lawn per application. In general, the recommendations printed on lawn fertilizer bags are designed to apply the maximum amount 1 pound of nitrogen per 1,000 square feet of lawn. For example, if you read on a bag of fertilizer that it will cover 5,000 square feet of lawn, it will deliver approximately 5 pounds of nitrogen to that area. Follow the bag directions and don't overapply.
	Return clippings to turf and cut one or two nitrogen applications in half. Similarly, cut rates in half in shaded areas.
	Consider using slow-release forms of nitrogen. Slow-release nitrogen fertilizers are designed to release nitrogen to the plants over a long period of time. Slow-release fertilizers include organic sources such as poultry manure or sewage sludge. Others include common nitrogen sources such as urea or ammonia nitrate that are coated with materials that release the nitrogen slowly over time. The portion of slow-release nitrogen available in the fertilizer product is listed as water insoluble nitrogen on the label. Choose products with slow-release nitrogen to reduce the potential for off-site movement.
	Keep fertilizers off impervious surfaces. Sweep fertilizer particles from driveways and sidewalks back onto the lawn area. This will prevent them from moving downstream with rain water.

Number and timing of applications: What are your goals? Carefully consider the function for your lawn along with the growing conditions on your property, and then set realistic objectives for your lawn. Choose your maintenance level and see the chart below for timing and number of fertilizer applications.

High maintenance situations: where a high quality, uniform, dense lawn or athletic field is desired and an irrigation system is available. The primary turfgrass species used in this situation is Kentucky bluegrass.

Medium maintenance situations: most general lawn or athletic field areas where supplemental irrigation will not be regularly applied, but the intention is to optimize turf growth for quality, density or playing conditions. Grasses are likely to be turf-type tall fescues or a mixture of grasses with more ryegrass in sun and fine fescue in dry or shady areas. New lawns planted from seed are likely to contain more ryegrass.

Low maintenance situation: lawn areas where the lowest level of input to maintain turfgrasses for a stable surface is desired. Grasses are likely to be turf-type tall fescues or a mixture of grasses with more ryegrass in sun and fine fescue in dry and shady areas.

Pounds of nitrogen per thousand square feet of lawn
Fertility Level	April	May	June	July	Aug	Sept	Nov
High 4-6# per year		1.0 and/or	1.0	0.5-1.0	0.5-1.0	1.0	1.0
Medium 3# per year		1.0 or	1.0			1.0	1.0
Low 1-2# per year						1.0 and/or	1.0

Michigan State University Extension programs and materials are open to all without regard to race, color, national origin, gender, religion, age, disability, political beliefs, sexual orientation, marital status, or family status. Feedback on this site should go to Jennie Stanger, stanger@msu.edu