# Finding The Actual Slow Release %

Discussion in 'Pesticide & Herbicide Application' started by The Ranger, Jan 21, 2006.

1. ### The RangerLawnSite Memberfrom NE OhioMessages: 208

Divide the slow release % on the label by the % of N in the bag; Example

32-5-7 with 6.8% slow release N

Divide 6.8 by 32 = 21% slow release N

just a little help from a friend

2. ### olive123LawnSite Senior Memberfrom ft lauderdale, FlMessages: 500

but 32 is not the amount of N in a bag its the pounds of N per 100 lbs of product

3. ### sildocLawnSite Silver Memberfrom Eagle Point, OregonMessages: 2,925

Ahh its the little things we over look that cause us so much greif.

4. ### ThreeWideLawnSite Bronze Memberfrom Georgia Z7Messages: 1,116

Unless I missed something major, I don't believe that is correct. Percentage is based on the weight of the bag/container regardless of size.

5. ### New GreenLawnSite Memberfrom Gorham MEMessages: 57

Seems so confusing... 32 is the number of passes you make if the spreader is set at #7 leaving a 5 ft swath.. 32-5-7.

BTW .. that formula is the same regardless of the lawn size.

6. ### olive123LawnSite Senior Memberfrom ft lauderdale, FlMessages: 500

DUH
i was drinking last night and was feeling harsh this morning...

sorry...

7. ### The RangerLawnSite Memberfrom NE OhioMessages: 208

The nutrient analysis on the label (32-5-7) represents the percentage by weight of the nutrients in the bag. 32%N, x50lbs. =16lbs of N, 5%P = 2.5lbs, & 7%= 3.5lbsK. The slow release formula in the original post represents how to figure what the slow release % is compared to the total amount of N. When they put slow release on the bag @ 6.8%, if you take 6.8% of 50lbs. = 3.4lbs. That means nothing unless you compare it to the total N. 3.4 divided by 16lbs of N = 21% 21% of the total N is slow the rest is fast.
Or divide the slow relase N 6.8 divided by the N number (32) = 21% slow release N. Both answers are the same and right, the one involves less math. Sorry for the confusion.

8. ### JBIRD33LawnSite Memberfrom GeorgiaMessages: 2

Actually you have to know the type of slow-release to make and accurate calculation. As far as PPSCU goes legally 90% of the slow-release can be claimed unless product is sold in Florida then only 50 % can be claimed. This should be expressed in units of Slow-release
Therefore a 50% slow release product like 32-5-7 would have 16 units of slow-release but the bag will say 14.4 units slowly available from PPSCU because of the 90% rule