The document provides information on calculating fertilizer requirements based on nutrient recommendations and fertilizer grades. It gives an example calculation for nitrogen, phosphorus, and potassium requirements and the amounts of ammonium sulfate, ordinary super phosphate, and potassium chloride needed. It then does calculations to determine the amounts of complete fertilizer, ammonium phosphate, and urea needed to meet the same nutrient recommendations. Finally, it lists and describes different methods for applying fertilizer, including broadcast, band, in-the-row, ring, hole, spot, basal, topdress, sidedress, foliar, and fertigation applications.

1. Fertilizer Computation
• Amount of Nutrient = amount of fert
material x fert grade
• Amount of Fertilizer material =
Recommendation
Fertilizer Grade
Calculate the amount of ammonium
sulfate (21-0-0), Ordinary super
phosphate (OSP) (0-20-0) and KCl (0-0-
60) needed if the recommendation
calls for the application of 120-40-30 kg
N – P2O5 – K2O/ha.
A.S = 120 kg N/ha
0.21
= 570 kg/ha
OSP = 40 kg P2O5/ha
0.20
= 200 kg/ha
KCl = 30 kg K2O /ha
0.60
= 50 kg/ha

2. • Calculate the individual of amount of
fertilizer materials using the following:
Complete (14-14-14), Ammonium phosphate
(16-20-0), and Urea (46-0-0)
• 1st Complete (14-14-14)
= 30 kg K2O/ha
0.14
= 214.28 kg/ha
214.28 kg complete x 0.14 = 30 kg P2O5
214.28 kg complete x 0.14 = 30 kg N
• 2nd Ammonium phosphate
= 10 kg P2O5/ha (16-20-0)
0.20
= 50 kg/ha
50 kg Ammonium phosphate x 0.16 = 8 kg N
• 3rd Urea (46-0-0)
= 82 kg N/ha
0.46
= 178.26 kg/ha
120
kg N
40 kg
P2O5
30
kg
K2O
Fertilizer Material
(kg)
30 30 30 214 kg
complete(14-14-14)
8 10 - 50 kg A.P(16-20-0)
82 - - 178.26 kg Urea (46-
0-0)

3. Fertilizer Application
• Broadcast - spread uniformly over the soil surface
• Band - spread on a narrow strip along the side of the row of plants
• In-the-row - applied along the bottom to furrow
• Ring - applied around the base of the plant or tree
• Hole - dropped in holes around the trees
• Spot - dropped in small amount on the side of each hill or plant.
• Basal - fertilizer applied at planting time
• Topdress - application sometime after plants have emerged
• Sidedress - placement beside the row of the crops such as corn or cotton
• Foliar - spraying of fertilizers on leaves
• Fertigation - application of fertilizer dissolved in irrigation water