Oftentimes, it is hard to irrigate a large field, even harder if different crops are grown in other seasons. Installing the permanent irrigation setup may not be suitable for the different crops, or sometimes it is not efficient to cover the entire land.
Irrigation systems like drip or sprinkler systems are suitable for specific crops, and irrigation like furrows can cover a large area but require heavy labor.
To solve the issue, center pivot systems came as saviors, covering the large land without installing a permanent setup.
In this post, we’ll dig deep into what the center pivot system is and the use cases, benefits, and drawbacks.
Understanding the Center Pivot Irrigation
In center pivot irrigation, the center tower is responsible for distributing the water to other towers that are moving, having electrically powered wheels, and many more moving towers based on the capacity and the area covered.
It’s like a giant wheel structure circling the center point, having a sprinkler to spray water.
To get a better understanding of the system, let’s look at the components and the working pattern.
How Center Pivot Irrigation Systems Work
The Fundamental Design
At its core, a center pivot irrigation system consists of several key components working in harmony:
Central Pivot Point:
The anchored center of the system serves as both the water entry point and the axis around which the entire structure rotates.
Main Pipeline:
A long steel or aluminum lateral pipe supported by a series of towers, extending from the central pivot outward like a radius.
Support Towers:
Mobile A-frame structures mounted on wheels support the pipeline and house the motors that drive the system’s rotation.
Sprinklers:
Water emission devices are positioned along the length of the pipeline that distribute water to the crops below.
Control Systems:
The electronic brain of the operation manages everything from rotation speed to water application rates.
The Mechanics of Operation
When in operation, water is pumped into the system through the central pivot point, flowing through the main pipeline and out through the sprinklers.
Imagine standing in the middle of a circular field and extending your arm straight out. Now, if you were to slowly spin in place while spraying water from your outstretched arm, you’d be doing essentially what a center pivot system does, just on a much larger scale!
The whole system is anchored at a fixed point in the center of the field (that’s the “pivot point”). This is where the water enters the system, kind of like water flowing into the shoulder of that outstretched arm. Then, the water travels through a long pipe (the arm itself) that’s propped up on several wheeled towers.
Here’s where it gets interesting. These towers don’t all move at the same speed. The tower at the very end of the arm has to cover much more ground than the towers closer to the center. It’s like if you had people standing along your outstretched arm, the person at your fingertips would need to walk much faster than someone standing at your elbow to complete a circle in the same amount of time.
So, the outer tower sets the pace, moving along at its steady speed, while each tower closer to the center moves progressively slower. This careful coordination is what keeps the whole arm straight as it rotates around the field. Without this synchronization, the arm would bend and possibly even fold up like a closing folding fan!
The towers themselves are pushed along by motors, either electric ones that run on power lines connected to the system or sometimes hydraulic systems powered by the water pressure itself. Modern systems have all sorts of sensors and alignment gadgets to make sure everything stays perfectly straight and moving at just the right speed.
Advantages of the Center Pivot Irrigation Kit
Water Efficiency and Conservation
Compared to traditional irrigation systems like furrow or flood, center pivot irrigation efficient in the usage of water.
- Water application efficiency typically ranges from 80-95%, compared to 40-60% for traditional surface irrigation methods.
- Precise control over application rates helps prevent overwatering and the associated leaching of nutrients from the soil.
- Lower pressure systems and drop nozzles position water closer to plants, further reducing evaporative losses.
Labour and Cost Reduction
If manual methods are followed to irrigate the land, it requires human effort. The automation inherent in center pivot systems dramatically reduces labor requirements:
- Once programmed, systems can operate with minimal human supervision, freeing farm personnel for other tasks.
- A single operator can manage irrigation across hundreds of acres—a task that would require multiple workers using traditional methods.
- Maintenance needs, while requiring technical knowledge, typically demand fewer person-hours than traditional irrigation infrastructure.
The economic benefits extend beyond labor savings to include:
Increased yield potential through optimized water delivery
- Reduced energy costs compared to some alternative pressurized irrigation methods
- Potential for fertigation (applying fertilizers through irrigation water), reducing fertilizer waste and application costs
- Extended growing seasons in some regions through more precise moisture management
Adaptability to Various Terrains and Crop Types
Center Pivot systems have remarkably versatile use cases.
- The system accommodates various field sizes through standard quarter-section systems (covering approximately 160 acres), half-circle configurations, or corner systems that irrigate traditionally missed corners.
- Properly designed center pivot systems can successfully irrigate most row crops, from corn and soybeans to specialty crops like potatoes and even some tree crops.
- When equipped with appropriate pressure regulators and anti-drainage valves, they can operate effectively on terrain with up to 15% slope.
- Different sprinkler packages can be installed to accommodate varying crop heights and water application needs.
These advantages determine why center pivot technology has been adopted in diverse agricultural regions worldwide, from the American Midwest to the Middle East, Australia, and beyond.
Now, look at some challenges you may face with center pivot irrigation systems.
Challenges and Limitations
Initial Investment and Ongoing Costs
The primary barrier to center pivot adoption remains the substantial initial investment:
- A standard quarter-section system can range from $50,000 to $100,000 or more, depending on features and terrain challenges.
- Additional infrastructure costs may include well drilling, pump stations, and electrical supply installation.
- Ongoing operational expenses include energy costs for pumping and system movement, regular maintenance, and occasional part replacement.
For many smaller-scale farmers, these costs can be prohibitive without financing assistance or governmental incentives.
Land Configuration Constraints
It is not an essay to set up the center pivot system for all types of land.
- Physical obstacles like buildings, power lines, or roads within fields require careful system planning or may render certain areas unsuitable for center pivot irrigation.
- Square or rectangular fields irrigated by center pivots typically leave approximately 22% of land unirrigated in the corners (though corner arm attachments can address this issue at additional cost).
- Irregularly shaped fields may not accommodate full-circle systems effectively.
The main culprit for the system is its circular design, which limits the pivot system to support all kinds of landscapes.
Technical Challenges and Maintenance Issues
To successfully operate the center pivot system requires addressing several technical considerations:
- Water Quality:
High mineral content (particularly iron or calcium) can clog nozzles and damage components over time.
- Pressure Management:
Insufficient pressure can lead to inadequate water distribution, while excessive pressure wastes energy and may damage components.
- Mechanical Failures:
Moving parts, including drive motors, gearboxes, and alignment systems, require regular maintenance and eventual replacement.
- Weather Vulnerability:
High winds can affect distribution patterns, while severe storms or tornadoes can damage the physical structure of the system. - Technical Expertise:
Modern systems with advanced controls require operator training and technological familiarity that may exceed traditional farming skill sets.
Even despite these challenges, the benefits typically outweigh the drawbacks for many agricultural operations, particularly as technology continues to improve and address these limitations.
Last Thoughts…
The Center Pivot system is solving irrigation problems, especially in large areas, irrigating the land in an effective and efficient way.
As we’ve explored, these systems offer remarkable benefits in water efficiency, labor reduction, and crop productivity while presenting challenges in initial investment. Mentioning the investments, yes, it may cost you upfront. However, analyzing deeply, like the yield you get and the lifespan, it turns out to be a good choice.
Investment Analysis Framework
Initial capital requirements:
System cost, supporting infrastructure, and potential field modification expenses.
Expected lifespan:
Typically 15-25 years for the basic structure, with component replacement cycles varying from 7-15 years
Operational costs:
Energy consumption, maintenance requirements, and potential water costs
Yield improvements:
Both increased production per acre and potentially expanded growing seasons
Risk reduction value:
Improved drought resilience and more consistent production
Looking ahead, the central pivot system plays an important role in irrigation as climate change has an impact on rainfall patterns and population growth, creating a high demand for food-efficient irrigation technology will be an essential component.
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