Fertilizer questions from a dummy

50lbs x 0.16 = 8lbs of N
50lbs x 0.04 = 2lbs of P
50lbs x 0.08 = 4lbs of K

This mean that N-P-K combined accounts for 14lbs of your 50lb bag. The rest is filler and trace elements. Note that the numbers combined can never be greater than 100 or 100%.

If, in our example, you want to use a 16-4-8 fertilizer and want 40lbs of Nitrogen per acre you would need to put down 250lbs per acre of the 16-4-8 fertilizer. This is because 40lbs divided by 0.16 is equal to 250lbs. Or another way to look at it is 250lbs times 0.16 = 40lbs.

If you spread this on an acre you would have put 40 units of N and 27 units of K on your acre.

If you put on 50 LBS of each you would have put 20 units of N and 13.5 units of K per acre

Gary

If you mixed together 100 LBS of 0-0-17 and 100 LBS of 40-0-10. You would have a 20-0-13.5 not 40-0-27 because by mixing two 100lb bags you now have 200lbs of fertilizer. Thus, for the Nitrogen, you have 40lbs in a 200lb mix. This is 20% of the 200lb mix (20-0-13.5).

Math is fun, huh?

No. It would be the weighted average of the two components. For example, if you had one pound each of the two different types, it would result in the average of the two, in this case 13 1/2.

If you had two pounds of the 10 and one pound of the 17, it would be 10+10+17 divided by 3 = 12 1/3. Etc. It's the weighted average, not the sum.

Good luck,

Tom in TN

Gerald J.