Question

how many lbs of 10-10-0 fertilizer should i apply?

Problem A1: Your soil test report said you needed 100 lb acre-i N and 30 lb acre-P,0. Your field is 0.5 acres. You have a bag of 46-0-0 and you have two bags of 10-10-0 (all bags are 100 lb each). What will you apply? Hint: Start with the 10-10-0 fertilizer since it contains two nutrients. Also, start with P because you will apply N with the P and usually applications of P are less than N. ibs of 10-10-0 to apply. 30 lb P₂O5 x 0. 5A

Answer 1

Since we need 30 lb/acre of P for the soil, and the total area of the field is 0.5 acres, the total amount of P needed is 30x0.5 = 15lb.

A 100 lb bag of 10-10-0 fertilizer will have 10% N and 10% P which means it will have 10lb P. We need 15 lbs total, thus, we need to use 1.5 bags of 10-10-0 lb.

Now, we need 100lb/acre of N, which means the total amount of N needed is 100x0.5 = 50 lbs. We have already applied 15lbs through 1.5 bags of 10-10-0 fertilizer. Now, we have to use the 46-0-0 fertilizer to apply the remaining 35lbs N. A 100lb bag of 46-0-0 fertilizer has 46lbs of N, while we need 35. Thus, we do not need to apply the whole bag, just (35/46) of it. Thus, the total amount needed to be applied is 76.09 lbs.

The total amount of fertilizer needed to be applied is 150 lbs 10-10-0 fertilizer and 76.09 lbs of 46-0-0.