IRRIGATION AND FERTIGATION
Irrigation is the artificial application of water to crops.
Fertigation on the other hand is the process of mixing soluble fertilisers through an irrigation system in
order to supply them to crops in soluble form.
Within the fertigation systems there are various channels by which the pumping system works through
until water and fertilizers are supplied to the crops.
The source of water for irrigation is the river, at which there is a pump house near the river that pumps
the water through the main pipe to the fertigation house. The daily consumption from the river is
8900m3. The master control valve in the pump house controls pressure from dam to fertigation. In the
fertigation house there is the centrifugal pump that sucks in water from the dam due to pressure
created and is aided by a mortar. Priming of the centrifugal pump is done in order to assist in the
creation of pressure to achieve the suction force needed to suck water from the dam. The pumps in the
fertigation house have filters to prevent dirt from passing to the pipes that would otherwise block the
drip emitters in the field resulting to uneven distribution of water in the blocks. There are three types of
filters;
a) Disc filters: They have discs in them.
b) Screen filters: They have wire mesh in them.
The pumps have a pressure gauge and the pressure is read in terms of bars. If there is a pressure
difference then there is a blockage in the pump and the filters have to be removed and cleaned.
Hydrogen peroxide is used to clean the dirt from the filters.
c) Gravel (carbonated filter): They are made of sand or gravel.
The fertigation jet is computerized and it relays information to the computer on how it relays water and
soluble fertilisers in the drips.
In the fertigation house the fertilizers are mixed in different tanks according to their chemical
composition to avoid forming crusts that could be as a result of chemical reaction.
Sulphates, nitrates and microelements are each mixed in different tanks.
The mixed fertilizers are then moved to the bottom tanks through pipes, then to the venturi which sucks
the dissolved fertilizer through the difference in pressure between the upper and the lower pipe. There
is a non-return rubber in the pipe to prevent water loss t venturi. The fertilizer is then mixed with water
at calculated amounts which is automated and taken to a booster pump.
The booster pump relays the fertilizer to the field through piping to the drip system where it will be
relayed to the crops. The positioning of the fertilizer movement near the venture is to allow for more
concentration of the fertilizer.
, When it comes to passing fertilizer through the pivot system, urea fertilizer is used. It is applied as a
foliar fertilizer, only to babycorn since it can cause scorching of leaves. Molasses and OSP are mixed at
the rate of 1:1:18, that is 10 litres of molasses mixed with 10 litres OSP and 180 litres of water. This is
important since it controls fusarium wilt. The pivot has a dosage pump to inject the worm tea in the pipe
in doses.
In the field the booster pump pumps water from the main pump to the drips, that is, it boosts the water
pressure that is in the pipes till the water reaches the blocks via the drip lines. Before the water reaches
the drip lines it has to pass via a series of connections. There is the sub main pipe that is buried
underground and transports the water from the booster pump. Within the sub main pipe perforations
are made and the start connector is inserted.
The hydrant is used to regulate the water flow in the drip lines, that is, it is opened and
closed to regulate flow of water into the drips. It has a red ball valve that is 4inch in size, which is
equivalent to 110 mm. It allows water flow into the pipe when it is open and limits water flow when it
closed. The air relieve valve is used to ensure that excess air is pushed out of the pipes to prevent
bursting due to pressure. Grommet rubbers are used to connect the start connector to the sub main
pipe. The start connector measures 12 by 16 mm. A P.E pipe is then connected to the start connector.
The drip connector then connects the P.E pipe to the drips. Water passes through these channels and it
is at the drips that the water is relayed to the soil. At some instances there may be need to connect one
drip to the other, for example, when the drip is short and needs to be lengthened or when the drip has
undergone damage and has been cutoff. In this case, a drip to drip connector is used. In the overhead
irrigation, a sandal clamps connects the pipe for overhead irrigation from the main pipe.
There are several types of drip lines that are used:
a) Hydro drip super
b) Rivulis
c) Typhoon( pressure compensated drips)
d) T tape
The selection of space of emitters in drips depends on:
a) Type of crop
b) Amount of water
The emitters should face up to:
a) Prevent blockages due to soil particles getting in them.
b) Avoid growth of algae due to solar effect.
The drips and pegs should be checked to ensure supply of water and blocking of drips, pressure and
disconnections.
Irrigation is the artificial application of water to crops.
Fertigation on the other hand is the process of mixing soluble fertilisers through an irrigation system in
order to supply them to crops in soluble form.
Within the fertigation systems there are various channels by which the pumping system works through
until water and fertilizers are supplied to the crops.
The source of water for irrigation is the river, at which there is a pump house near the river that pumps
the water through the main pipe to the fertigation house. The daily consumption from the river is
8900m3. The master control valve in the pump house controls pressure from dam to fertigation. In the
fertigation house there is the centrifugal pump that sucks in water from the dam due to pressure
created and is aided by a mortar. Priming of the centrifugal pump is done in order to assist in the
creation of pressure to achieve the suction force needed to suck water from the dam. The pumps in the
fertigation house have filters to prevent dirt from passing to the pipes that would otherwise block the
drip emitters in the field resulting to uneven distribution of water in the blocks. There are three types of
filters;
a) Disc filters: They have discs in them.
b) Screen filters: They have wire mesh in them.
The pumps have a pressure gauge and the pressure is read in terms of bars. If there is a pressure
difference then there is a blockage in the pump and the filters have to be removed and cleaned.
Hydrogen peroxide is used to clean the dirt from the filters.
c) Gravel (carbonated filter): They are made of sand or gravel.
The fertigation jet is computerized and it relays information to the computer on how it relays water and
soluble fertilisers in the drips.
In the fertigation house the fertilizers are mixed in different tanks according to their chemical
composition to avoid forming crusts that could be as a result of chemical reaction.
Sulphates, nitrates and microelements are each mixed in different tanks.
The mixed fertilizers are then moved to the bottom tanks through pipes, then to the venturi which sucks
the dissolved fertilizer through the difference in pressure between the upper and the lower pipe. There
is a non-return rubber in the pipe to prevent water loss t venturi. The fertilizer is then mixed with water
at calculated amounts which is automated and taken to a booster pump.
The booster pump relays the fertilizer to the field through piping to the drip system where it will be
relayed to the crops. The positioning of the fertilizer movement near the venture is to allow for more
concentration of the fertilizer.
, When it comes to passing fertilizer through the pivot system, urea fertilizer is used. It is applied as a
foliar fertilizer, only to babycorn since it can cause scorching of leaves. Molasses and OSP are mixed at
the rate of 1:1:18, that is 10 litres of molasses mixed with 10 litres OSP and 180 litres of water. This is
important since it controls fusarium wilt. The pivot has a dosage pump to inject the worm tea in the pipe
in doses.
In the field the booster pump pumps water from the main pump to the drips, that is, it boosts the water
pressure that is in the pipes till the water reaches the blocks via the drip lines. Before the water reaches
the drip lines it has to pass via a series of connections. There is the sub main pipe that is buried
underground and transports the water from the booster pump. Within the sub main pipe perforations
are made and the start connector is inserted.
The hydrant is used to regulate the water flow in the drip lines, that is, it is opened and
closed to regulate flow of water into the drips. It has a red ball valve that is 4inch in size, which is
equivalent to 110 mm. It allows water flow into the pipe when it is open and limits water flow when it
closed. The air relieve valve is used to ensure that excess air is pushed out of the pipes to prevent
bursting due to pressure. Grommet rubbers are used to connect the start connector to the sub main
pipe. The start connector measures 12 by 16 mm. A P.E pipe is then connected to the start connector.
The drip connector then connects the P.E pipe to the drips. Water passes through these channels and it
is at the drips that the water is relayed to the soil. At some instances there may be need to connect one
drip to the other, for example, when the drip is short and needs to be lengthened or when the drip has
undergone damage and has been cutoff. In this case, a drip to drip connector is used. In the overhead
irrigation, a sandal clamps connects the pipe for overhead irrigation from the main pipe.
There are several types of drip lines that are used:
a) Hydro drip super
b) Rivulis
c) Typhoon( pressure compensated drips)
d) T tape
The selection of space of emitters in drips depends on:
a) Type of crop
b) Amount of water
The emitters should face up to:
a) Prevent blockages due to soil particles getting in them.
b) Avoid growth of algae due to solar effect.
The drips and pegs should be checked to ensure supply of water and blocking of drips, pressure and
disconnections.
