Broadcasting – random scattering of the fertilizers on the ground.
Placement method– application of fertilizers in the planting holes.
Side dressing – fertilizer is placed at the side of the plant within the root zone, in bands or spot-rings.
Foliar spraying – specially formulated fertilizer solution applied on the foliage in spray form.
Drip method – applied through irrigation water.
Determination of Fertilizer Rates

Contents of fertilizers are expressed as fertilizer grade or fertilizer analysis.

Fertilizer grade indicate the guaranteed minimum of the active ingredients (N, P205, K 20) in the mixture.
It is expressed as a percentage on a weight to weight basis or percentage by weigh

Example 10:20:o means for every 10kg of the mixture there are 10kg of nitrogen, 20kg of P10 5 and 1okg of K20.

Example

A farmer was asked to apply fertilizers as follows:

60 kg/ha nitrogen (top dressing)
60 kg/ha P205 (in planting hole).
60 kg/ha K20. How much sulphate of ammonia (20%) would be required per hectare? How much double super-phosphate (40%) P2O5would be required per hectare? How much muriate of potash (50% K20) would be required per hectare?

Answer/Solution

Sulphate of ammonia (SA) which gives 60kg/ha N

60/20 x 100 = 300 kg SA

Double super phosphate (40% P2O5)which gives 60kg/ha P205

60/12 x 100 = 150 kg DSP

Muriate of potash (60% K20) which gives 60kg/hK2O

=60/60 x 100 = 100 kg muriate of potash

Example

A farmer was asked to apply fertilizers as follows:

200kg/ha of DSP (40% P205

150kg/ha of muriate of potash (60% K20)

150kg/ha of sulphate of ammonia (20% N)

How much P205 did the farmer apply per acre?

How much K20 did the farmer apply per hectare?

How much N did the farmer apply per hectare?

P205 applied per hectare from 200kg of DSP 40/100 x 200 = 80 kg/ha P205

K205 applied per hectare from 150 kg of muriate of potash = 60/100 x 150 = 90 kg/ha K20

N applied per hectare from 150 kg/ha sulphate of ammonia 20/100 x 150: 30 kg/ha N