Center pivot irrigation or drip irrigation: what’s the difference and which method should you use?

First we need to understand how these two methods work AND how they differ from one another. In this piece, we give a brief overview of the two methods and highlight why center pivot irrigation should be your first choice when it comes to deciding how you want to irrigate your fields.

We base our opinion on three main considerations: (1) initial investment cost, (2) labour requirements and (3) peace of mind.

What is drip irrigation?

Drip irrigation is a form of irrigation that saves water and fertiliser by allowing water to drip slowly to the roots of crops in a field, either onto the soil surface or directly onto the root zone, through a network of valves, pipes, tubing, and emitters. It is done through narrow tubes that deliver water directly to the base of the plant.

Typically, drip irrigation is a good irrigation option in small or irregularly shaped fields. Many growers, however, tend to use this method on normal-sized fields because they believe that this method uses water optimally. Seeing as the tubes that deliver the water is either placed underground or directly on the surface of the soil, there is basically no chance of water evaporation.

What is center pivot irrigation?

Center pivot irrigation is a mechanized irrigation system that irrigates crops in a circular pattern around a central pivot. It consists of a radial pipe supported by towers that pivot around a central point. Along the radial pipe, nozzles are spaced to ensure optimal efficiency and coverage. As it rotates, water is released from the nozzles and irrigates crops.

This kind of irrigation system is ideal for average- and large-sized fields. Keep in mind, though, that pivot companies also offer affordable solutions specifically designed for smaller fields too. It possesses many benefits to growers (as will be shown below) seeing as this method delivers uniform water application, requires no human labour and can function even with low water pressure.

Center pivots can also be even more efficient if incorporating modern emitters (sprinklers) or new technologies, such as Variable rate irrigation, where we can control the flow of each sprinkler adapting the machine to different soil or crop types.

Finally, pivot irrigation is often viewed as a sustainable solution for growers that work with different crops. One center pivot is able to easily handle multiple crops under it.

Initial investment costs

On average, it is far cheaper to purchase and set up a center pivot on a farm than it is to install a drip irrigation system. In fact, surveys have shown that center pivots are between 20% and 50% cheaper to install than drip irrigation!

When it comes to maintenance, it is estimated that one can budget on spending at least 7% - 10% of the initial cost of a drip irrigation system on its upkeep. Center pivots cost a fraction of this to maintain. Usually, upkeep on a pivot would amount to a maximum of about 2% of the initial cost of the equipment.

Of course, the future value of the equipment must also be taken into consideration. Pivots, especially galvanised ones like the ones Zimmatic produces, last for many years. In fact, pivots tend to last more than 25 years, whereas drip systems are expected to only be functional for 10 - 15 years. In fact, the annual maintenance costs required on drip systems that is supposed to run 10 - 15 years is more than the price of a new pivot.

For farmers who come from a long line of growers and who plan to leave their farm to their children, buying a center pivot is a long-term investment. Seeing as Zimmatic pivots are long-lasting and robust, they will still function even when a farmer passes his farm to his kin who will take over the operation. As explained above, drip systems have a limited lifetime and in all likelihood won’t be able to service successive growers.

Center pivots typically also retain their value, meaning that a grower can still get a good price for his pivot if, for some reason, he decides to sell it one day. With drip irrigation systems, you probably have to pay someone to remove it from your field if you want to get rid of it!

Labour requirements

Drip systems are notorious for the amount of labour it requires to maintain and operate them. To install drip systems is a tedious task and requires specialist knowledge. Once set up, the drip system is bound to one particular field and cannot be moved to another field. Drip irrigation systems also require that growers walk an entire field to monitor the status of the system, flush filters and maintain tubes. This task takes a lot of time and labour resources that could have been spent more productively. Although some basic automation technology does exist for drip irrigation, it is largely a manual practice.

Center pivots, on the other hand, require less in terms of labour. Pivots are relatively easy to set up and their installation is standard practice. Pivots are not bound to one set field, they can be moved around on a farm easily and there is no need to hire labour to break down and reinstall the pivot when a season comes to its end.

What really sets a center pivot apart is that it does not require any human labour in order to function. By using the latest technology in pivot monitoring and control, a farmer can keep an eye on the status of his center pivot from anywhere in the world using a remote irrigation program, like FieldNET. These programs give growers the ability to control their pivots remotely, meaning that they do not need to dispatch a team of workers to the equipment to turn it on or to check on its progress. Everything can be managed right from the palm of your hand.

Peace of mind

As explained above, drip systems require constant maintenance and visual inspections. They also require a certain amount of skill on the part of the person who will be tending to the system, meaning that sometimes, a farmer would have to go for training or enlist the help of a specialist to operate their drip systems. Another potential issue is that drip irrigation pipes and tubes are buried underground. If a problem needs to be detected or fixed, it can be time-consuming and expensive to dig the system up and rectify the situation. Possibly the biggest downside to drip irrigation is the fact that it is very dependent on water quality for optimal functioning. Using wastewater on a drip system requires larger, more expensive equipment if they want to curb their water usage. In countries facing serious droughts and water restrictions, this is problematic. Thus, a grower will probably never have complete peace of mind about their drip irrigation, due to its tedious operational requirements and obvious drawbacks.

Pivots provide greater peace of mind. Center pivots are easy to operate and very little training is needed to know how to install or move them from field to field. Because center pivots can be remotely monitored and controlled, detecting potential issues they might run into is a stress-free exercise. Growers can also rest assured that their pivots will complete an irrigation cycle with very little human intervention needed. They simply need to activate the pivot, and the machine does the rest on its own. Remote irrigation software will alert a grower of any problems immediately, so there is no need to spend time searching for the issue. Of course, there is also no need for visual inspections of the equipment when remote irrigation management software is in play.

Perhaps one of the biggest advantages of center pivots is that they can be run with wastewater. These pivots are robust and durable. Using wastewater for irrigation won’t damage the equipment and there is no need for a farmer to purchase any additional products in order to use alternative water sources. In times when water is scarce, this should be the deciding factor for any farmer looking to make an impact on their water consumption.

Where to order center pivots?

Zimmatic, a product of Lindsay, produces industry-leading irrigation equipment. These products include durable center pivots. The 9500P Center Pivot is the most robust pivot in the Zimmatic product range. By combining unbeatable strength and the latest in irrigation technology, this pivot delivers a fully integrated solution perfect for any grower’s situation.

There are several knowledgeable Zimmatic dealers throughout Europe. These irrigation specialists can assist you in determining what the needs of your field are and how a Zimmatic pivot can improve your irrigation operation.