The irrigation, constitutes diverse procedures that allow the efficient distribution of the water on the surface of the ground. Currently, there are different types of irrigation that make it easier for the farmer to compensate for the lack of rainfall and the supplies needed for plant growth.
Irrigation by Gravity
Gravity irrigation, also called surface irrigation, consists of the distribution of water through channels or furrows, which are arranged throughout the cultivation area.
To carry out this type of irrigation, the farmer must have a reservoir or pond large enough. In it will accumulate all the water, which by means of long ditches will go to the irrigation points.
Once the water runs through the channels, the force of gravity will be responsible for distributing it through the surface of the crop.
Flooded crops using the gravity irrigation technique
This method of irrigation is one of the oldest in agriculture. To do this, the farmer must have adequate knowledge about the infiltration capacity of the soil. Thus, once the saturation point is reached, you must stop the flow of water and prevent the flooding of the land .
In order to ensure the success of gravity irrigation, it is necessary to carry out previous studies that allow knowing the most appropriate plantation frames according to the crop.
- – Gravity irrigation, due to the simplicity of its infrastructure, is one of the most economical.
- – The energy requirements for its operation are practically nil, thanks to the use of gravitational energy.
- – Wind is not a limiting factor in the distribution of water.
- – It is not convenient to use it in uneven terrains, since the water could be diverted and prevent its correct distribution.
- – By moistening most of the land can cause the appearance of weeds and diseases of fungus type.
Currently, in gravity irrigation, it is also possible to use multi-door pipes. This technique allows water to be distributed by means of hydratants, or pipes connected to the source of supply.
These pipes are located along the plot and have small gates that regulate the flow of water. In this way a uniform irrigation is guaranteed and without the need for a worker to supervise.
They can also be built with mobile PCV irrigation pipes, valves for discontinuous flow, and addable gates. All materials are easily accessible and inexpensive.
This type of irrigation consists in driving the water through sprinklers that moisten the ground in a similar way as the rain would.
Currently there is a wide variety in sprinkler irrigation systems, there are mobile, fixed and self-propelled.
These, in their majority, can be installed in any type of topography, which is an important advantage. However, it should be noted that in the case of sprinkling, wind can be a limiting factor.
It is recommended to be installed on land with winds of less than 15 km / hr, especially in fruit crops and vegetables.
They consist of several pipes, which are under the surface of the land, and are connected to rotating nozzles. These nozzles spread the water in a circular way.
The location of this type of sprinkler can be arranged in a square, rectangular or triangular shape. As long as the sprinkler radii are located and do not leave spaces to which the irrigation does not reach.
The type of nozzle will determine the size of the drops. The smaller they are, the more likely it is that the wind will deflect the direction or evaporate. On the other hand, if they are very large, they can cause damage to the land and to the crop plants.
To guarantee irrigation efficiency it is important to consider the characteristics of the sprinkler as a function of: the nominal working pressure, the nozzle flow rate (liters per hour), the reach diameter, and the precipitation (liters per square meter).
Among the most common are impact, double nozzle, and medium pressure. The latter reach nominal working pressures ranging between 2.5 and 4 atmospheres, allowing frames up to 18 meters with a good uniformity of irrigation.
They consist of a system of underground pipes, connected to sprinklers that change their position manually whenever it is necessary to irrigate an area of the plot . They are suitable for small surfaces and are generally found at low height.
Usually the sprinklers are located on a mobile cart that runs through the plot while wetting the ground.
Pivot powered by electric motor
The self-propelled aspersion consists of a slightly more complex structure . To this category the so-called pivot or pivot perish.
The water supply in a pivot system is more than 1.0 meters deep. They are able to reach great distances but only water in a circular way . This is why it only adapts to plots of a certain size and regular shapes.
The movement is made thanks to electric motors. The equipment also has a lifespan of 15 to 20 years, with a 75 to 90% efficiency.
Another variation of self-propelled irrigation are the traveling cannons. Which, thanks to its pressure system, can irrigate from 2.5 to 15.0 hectares per sprinkler .
They can be moved by tractor, or they are self-propelled by some type of electric motor or gasoline.
The main drawback of this sprinkler system is that as the water reaches more height and distance, it can be affected by the wind. On the other hand some crops are very sensitive to the force of water pounding.
- – In general , sprinkler irrigation is one of the most used. Although depending on the system will be more or less expensive, its efficiency is much higher than other types of irrigation.
- – They are able to cover large distances of land
- – They adapt to the type of plot
- – They allow to automate the irrigation
- – The lifespan of these systems is much higher
- – Investment and labor can be high.
- – The installation of these systems is much more complex
- – Like gravity irrigation could increase the appearance of weeds.
It is an irrigation used mostly in arid areas. It consists of distributing the water already filtered and with fertilizers on or in the soil . In this way the water arrives directly at the root zone of the cultivated plants.
The distribution is made through a network of pipes, usually made of plastic, either polyethylene or hydraulic PVC on the main lines. In the lateral lines it is made with flexible or rigid polyethylene pipe.
Polyethylene pipe used in drip irrigation systems
The drip irrigation allows to avoid the fluctuations of humidity that is had with the other types of irrigation. It can be applied 2 or 3 times a day.
Drip irrigation can be used both in the open air and in greenhouse crops. It is recommended for crops planted in row either annual or perennial cycle . In addition, it is currently being used also for crops managed in hydroponics, where yields far exceed crops sown directly to the soil.
- – Allows adequate growth of the root system
- – It can maintain an almost constant humidity by continuously renewing the volume of water that is spent by the evapotranspiration process.
- – Allows the application of fertilizers in the irrigation water. This guarantees a greater availability of nutrients to the root zone.
- – The soil of the plot does not get wet, but only the row where the crop is planted. This is an important advantage to reduce the possible appearance of weeds.
- – Water consumption decreasesand the efficiency of water use increases remarkably.
- – Although irrigation is being carried out, other cultivation tasks such as pruning, trellising and agrochemical application can be carried out . Activities that can not be performed simultaneously when using gravity or sprinkler irrigation.
- – It adapts to rocky terrains or slopes.
- – The most important disadvantages of this irrigation method is that the drip system can be covered if the water is not filtered correctly
- – In addition, the initial investment is high and it is essential to have trained technical personnel for the design. As well as the correct installation.
- – Installation and design costs are high.
Undoubtedly, the proper use of irrigation systems will often depend on the ability of the farmer to assess the needs of the crop. As well as factors of a natural, technical and economic nature that intervene in productivity