The document discusses how to calculate fertilizer requirements based on recommended nutrient doses. It provides fertilizer factors for common fertilizers like urea, DAP, SSP, and MOP based on their nutrient contents. It then shows examples of calculations to determine the required amounts of different fertilizers given a recommended dose of 120:60:40 kg/ha of N:P:K. The amounts calculated are 260.4 kg/ha of urea, 375 kg/ha of SSP, and 66.67 kg/ha of MOP. A second example calculates the amounts of DAP, urea, and MOP as 130.43 kg/ha of DAP, 210.87 kg/ha of u

1. Fertilizer
calculation

2. Fertilizer required=
100
nutrient content(%)
×Recommended dose of fertilizer
• In case of Urea=
𝟏𝟏𝟏𝟏𝟏𝟏
𝟒𝟒𝟒𝟒
= 2.17
(factor)
• DAP (for N)=
𝟏𝟏𝟏𝟏𝟏𝟏
𝟏𝟏𝟖𝟖
= 5.55
• DAP (for phosphorus)=
𝟏𝟏𝟏𝟏𝟏𝟏
𝟒𝟒𝟒𝟒
=
2.17
• SSP=
𝟏𝟏𝟏𝟏𝟏𝟏
𝟏𝟏𝟏𝟏
= 6.25
• MOP=
𝟏𝟏𝟏𝟏𝟏𝟏
𝟔𝟔𝟔𝟔
= 1.67
FERTILIZER
NUTRIENT
%
FACTOR
UREA 46% N 2.17
SSP 16% P₂O₅ 6.25
MOP 60% K₂O 1.67
DAP
18% N
46% P₂O₅
5.55
2.17

3. 1. The recommended dose of fertilizer is
120:60:40 kg/ha. Calculate how much Urea,
SSP & MOP will be required for this.
Solution:
Fertilizer requirement will be,
• Urea =120×2.17= 260.4 kg/ha
• SSP= 60×6.25= 375 kg/ha
• MOP= 40×1.67= 66.67 kg/ha

4. 1. The recommended dose of fertilizer is 120:60:40 kg/ha. Calculate
how much DAP, Urea & MOP will be required for this.
Solution:
DAP contains 18% N & 46% P₂O₅
Now, first we have to calculate fertilizer dose for highest nutrient content in given fertilizer.
Fertilizer requirement for Phosphorus will be,
• DAP (for Phosphorus)=60×2.17= 130.43 kg/ha
• Now let’s check how much N supplied through 130.43 kg DAP fertilizer as it also contain
Nitrogen(18%).
• 100 kg of DAP contain 18kg of N.
• 130.43 kg DAP contain =(18/100) × 130.43= 23.48 kg
23 kg of N requirement is fulfilled through DAP.
• Rest 97kg N (120-23=97kg) will be supplied through Urea.
• Urea (for N)= 97×2.17= 210.87 kg/ha
• MOP= 40×1.67= 66.67 kg/ha