Agriculture plays a very important role in the country's economy and the search for productivity security is increasingly present. In this, to compensate for the effects of the lack of rain, alternatives are sought in irrigation systems, where the irrigation pivot stands out. According to the National Water Agency (ANA), the irrigation pivot area in Brazil corresponds to 1.6 million hectares and more than 25,000 equipment is installed, with an annual growth of approximately 100,000 hectares, which will double the irrigated area until 2040
The irrigation pivot is the system that has been growing the most in irrigation systems, due to its easy handling, mainly due to technology. It can be installed in small, medium and large properties, in the most extensive regions of the country and abroad. By equipment, the system allows installation in areas ranging from 3 hectares to more than 300 hectares and are installed for a useful life of 15 to 25 years.
Irrigation benefit
The main benefit of irrigation is the increase in productivity, which can reach up to 3 times when compared to rainfed agriculture (without irrigation). Check out other benefits below:
- Minimization of risks due to lack of water;
- Possibility of including an annual crop;
- Application of pesticides and fertilizers when the crop needs it;
- Possibility of applying fertigation (water and fertilizers).
Management is also important and the amount of water applied varies according to the soil, culture and stage of the crop. Both the lack of irrigation and the excess generate loss in productivity.
Center pivot irrigation system
The central pivot irrigation system consists of a pump, a water main and the aerial part, as shown in the image below:
The water is captured during pumping by a motor-pump set, which can be driven by an electric or diesel engine; It is then transported through the pipeline, entering the aerial part through the central fixed tower.
The shoots of the aerial part, together with the drive tower, vary in quantity according to the irrigated area, and can exceed 20 towers and 1000 meters in length and revolve around the central tower. Each lance has a number of sprinklers that distribute the water throughout the equipment, applying the requested blade.
There are systems on the market where the drive tower is activated by contact, causing intermittent movements. In other cases, the movements are more precise, with frequency inverters, which generate continuous movements, creating more uniform slats and less structural stress, especially in areas with greater slope.
Sizing the irrigation system
The irrigation system is dimensioned according to the irrigated area and the applied depth, which differ according to the region, soil and culture. Projects currently range between 8 mm and 15 mm of water per day.
To define the characteristics of the equipment, a topographic survey is necessary to verify the slope of the area and the manometric height until the water capture. Pumping can be of fixed or variable rotation, for large differences in the equipment and/or that have variation in the level of the dam, it is recommended to use variable rotation systems, as they reduce excess pressure and can generate savings of up to 40% in consumption.
Irrigation pivot operation
The irrigation pivot has a control panel in the central tower that is used for the operation, control and monitoring of the equipment, and can also be operated and monitored remotely via computer or cell phone. It is an easy-to-operate equipment, where the blade to be irrigated, the destination position and the direction of rotation are informed, with little involvement in handling.
Irrigation system cost
The cost for installing an irrigation pivot varies according to the area to be irrigated, the daily depth, the manometric height, the distance between the pump and the central tower, the slope of the area, among other factors, ranging from 20 to 35 thousand reais per hectare.
Smaller equipment has a higher cost per hectare, and this is because the smaller the equipment, the lower the average irrigated per pitch. The investment in irrigation pivot is viable, because in addition to guaranteeing the harvest and quality, the return on investment occurs in approximately 4 years. In addition, in a decade, an average of 6 years is reached with some loss due to drought.
