(IPPM) in Vegetables - Vegetableipmasia.org

Resource Manual on IPPM in Rice
World Education Philippines, Inc.
Example 2
If one wants to apply 80 kilograms per hectare of phosphorus (P 2 O 5 ) as a single
superphosphate (20% P 2 O 5 ), the computation appears below:
80
20
x 100 = 400 kg/ha
b. How to calculate the percentage of fertilizer elements from known amounts of
fertilizer materials
To determine the analysis of a fertilizer mixture, multiply the quantity of fertilizer
by the percentage of N, P 2 O 5 or K 2 0 in it and divide by 100.
Example 1
Given a quantity of fertilizer with the following composition, how will you find
the number of kilograms of available nitrogen, phosphate, and potash in the
mixture
· 150kg of ammonium sulfate analyzing 21% N
· 600kg superphosphate analyzing 20% P 2 O 5
· 100kg potassium chloride analyzing 60% K 2 0
· 850 kg total weight
Solution:
520 kilograms of ammonium sulfate (21% N)
520 x 21%
100
600 x 20%
100
100 x 60%
100
= 109 kg of nitrogen
= 120 kg of phosphate
= 60 kg of potash
How will you find the percentage of N, available P 2 O 5 and K 2 0 in the whole
mixture
Solution:
Divide the weight of each plant nutrient by the total weight of the mixture and
multiply by 100, thus:
29