How to calculate fertilizer application
at a 1 lb. rate per 1000 sq. ft. rate
If you had a 100 pound pile of 18-5-9 fertilizer. In
that pile would be 18 pounds of Nitrogen or 18%. Also included in that pile would be 5
pounds of phosphorus compound or 5%. And lastly in that same pile would be 9 pounds of a
potassium compound or 9%. That is what that number 18-5-9 means.
In order to apply one pound of Nitrogen to 1000/sq. ft. we would apply 5.6 pounds of
18-5-9, because it's only 18% Nitrogen. To arrive at this figure of 5.6 we divided 1 by
.18. In this example if we wanted to apply 18-5-9 at a 1 lb. rate on an acre of land we
would multiply the 5.6 pound of fertilizer by 43.56 since there is 43,560 square feet per
acre.
Other sample calculations are:
12-4-8 1 divided by .12 = 8.3 lb. per 1000
sq. ft. = multiplied by 43.56 = 363 lbs. / acre
20-5-10 1 divided by .20 = 5.0 lb. per 1000 sq. ft. = multiplied by 43.56 = 218
lbs. / acre
Most Lawn Care Service Companies do a good job of providing there turf services in a
timely fashion for a fair price. If you want to do it yourself and want to continue to
educate yourself about turf maintenance and what are the current recommended chemicals to
use, contact you local county extension service.
Remember that this area is a tough area to grow grass and every yard is different. You
have to decide how good you want your yard to look, how much time you want to spend, and
how much money you want to spend.
