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What do Helicopters Spray on Crops and Fields?


Aircraft, including helicopters, have been used to spray or drop various substances over crops and fields for decades. Aerial chemical application in various settings, whether it be for spreading insecticides over crops or fertilizers over fields, is considered one of the most cost-effective methods of ensuring the health and wellbeing of dozens of crop types, especially when the terrain prevents the use of regular farm application machines.

Helicopters are used for aerial application in rugged, mountainous, inaccessible, or smaller fields due to their slower flight speed and accurate delivery capabilities. They commonly apply seeds, fertilizers, herbicides, fungicides, and insecticides in liquid or pellet form.

In the United States alone, there are over 1,500 aerial application businesses and around 3,400 agricultural pilots. The most common types of helicopters used to spray crops range from small Hiller’s and Robinson R44’s up to the Bell 206 Jet Ranger and Eurocopter AS315 Lama.

So below, we’ll look more into why helicopters are used by industry and farmers to spray crops, as well as what particular chemicals are released on agricultural fields.

Why are Helicopters Used for Crop Spraying?

Using helicopters is one of the quickest ways to apply chemicals to fields and crops. When very large, relatively flat fields require application then an airplane is a much better option, but when the application areas are small, rugged, or in mountainous terrain, the helicopter is the better choice.

Here is why helicopters are extremely practicable:

Accuracy

Helicopters are able to access crops directly from the sky and can fly very low to the ground. They’re able to maneuver over particular areas of the field with almost pinpoint accuracy, providing a much more useful alternative to fixed-wing aircraft which are not as maneuverable, especially at low speed and low altitude.

Each product has a designated application method and because of the adjustable speed and maneuverability of a helicopter, the pilot can fly at the correct height and speed to apply the exact amount of product leading to the most efficient coverage of the application area.

This prevents excess chemical usage which costs the farmer.

Less Ferrying Time

One of the best reasons why helicopters make great aerial application tools is that helicopters can resupply from a truck next to the field, unlike a fixed-wing aircraft which must use at an airstrip or suitable dirt road or clearing to resupply which may be quite some distance from the application area.

Can’t Get Much Closer! – Source: Carl Wycoff

Airplanes also need to fly back to the landing strip to reload with fuel before taking off again, whereas a helicopter can also do that from the truck. Having the reload site right next to the application area makes the whole process cheaper, as using helicopters decreases the amount of ‘ferry time’.

When an. application cycle can be as short as 5 minutes, flying back and forth to an airstrip dramatically extends the application time, and having only small windows when the weather conditions are perfect can lead to more days being on site costing the farmer more money.

Agility

When trees, hedgerows, powerlines, or obstacles present themselves the pilot is able to stop the product release, maneuver around the obstacle, and then continue applying with minimal effort. This keeps the application time to a minimum, thus keeping the costs low for the farmer.

Helicopters can also fly much slower than an airplane. Airplanes generally can only operate as slow as 60 miles per hour (100 km/h) whereas helicopters can fly at speeds all the way down to zero. When application areas are irregularly shaped or prevent complex application the pilot can adjust the product’s application rate, altitude, and airspeed to ensure maximum product coverage much easier with a helicopter than with an airplane.

Airplanes may be unable to apply product in such conditions.

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What Chemicals do Helicopters Spray on Crops and Fields?

Helicopters typically apply pesticides, herbicides, and fungicides in liquid form using a tank, pump, and spray bar attached to the underside of the helicopter. Seeds and fertilizers are usually in pellet form and are spread using seeding hoppers slung from the belly hook of the helicopter.

The agricultural industry applies various types of chemicals to their fields to ensure the health and wellbeing of their crops for maximum harvest yield or to control invasive species within the area.

Below are some of the different types of chemicals that helicopters will spray on fields, cut blocks, utility corridors, or forest areas.

Insecticides

Spreading insecticides, also known as pesticides on crops is integral to ensuring a crop lives a healthy and long life. Insecticides are the substances used to kill insects and pests which pose a risk of destroying crops, ranging from aphids and mealybugs to bollworms and berry borers.

Usually, the pesticide is designed to attack only the intended pest and today’s chemicals are highly advanced to ensure environmental impact is minimal.

Some Aerial Application Helicopters can be Transported Right to the Worksite to Save on Flying Costs.

Herbicides

Herbicides are chemicals used to spray crops so that unwanted vegetation, typically weeds, dies. Just like the insecticides, these chemicals are highly toxic to specific types of plants and are often used in row-crop farming or reforestation where the landowners only want new trees to grow and not invasive species.

By killing off the unwanted plants the crop will be able to consume the required nutrients from the soil without having to compete with the weeds. This leads to a better, healthier, and increased coverage of the required crop.


Case Study: The risks of spraying herbicides by helicopter

There are risks involved with aerial application and below is an example of where pilot negligence can really affect many people.

It is extremely important that herbicides (and all chemicals) are sprayed with precision and in the right locations. Spraying accidents such as ‘Chemical Drift’ are very possible with helicopters. It is for this reason that most agricultural staying is done at first light when there is no wind.

In October 2013, a Bell OH-58A helicopter in Oregon was alleged to have affected members of the public while releasing herbicides over logging clear cuts, leading to 20 different complaints from Curry County. A baby was reported vomiting for 24 hours, suffering headaches, gastrointestinal issues, and sinus problems.

The FAA suspended the pilot’s license for a year, as was his company’s application license. He was made to pay $1,100 in penalties by the Environmental Protection Agency but reportedly managed to avoid a potential fine of $20,000.

This case highlights the importance of avoiding ‘drift’ when spraying chemicals for a helicopter. Pilots can achieve this by using larger spray droplets with a low level of pressure, while only releasing the herbicides at low altitudes and when the wind speed is low.


Fungicides

Fungicides are the chemicals used to destroy fungi and any spores they produce. Fungi have significant potential to damage plants and crops under the right conditions causing mold and mildew on the crop itself.

A notable example of a fungicide that can be sprayed by a helicopter is Headline, which contains the Group 11 fungicides Pyraclostrobin and Metconazole. This product is marketed to address over 50 diseases that threaten crop quality and can be effectively sprayed by helicopter.

“I had two farms with soybeans that were heavily damaged by hail … and I wanted to get Headline applied to ward off any disease. My crop representative recommended aerial application as an option and I was impressed to see how close the helicopter pilot got to the crop … he didn’t have his boom any higher than a typical Ro Gator would and he was very precise!”

Kris Martin, Martin Farming (Brant County, Ontario, Canada)

Fertilizers

Helicopters may also apply various fertilizers over crops and fields. These are substances designed to make crops more fertile by providing them with the correct nutrients required for them to stay productive. Aerial application is typically considered a very quick way to deliver nutrients to crops at the perfect time in the growing cycle.

AgroLiquid, for example, is a fertilizer commonly used on a range of crops such as sugar beets, rangeland, alfalfa, corn, and wheat. The company states that applying AgroLiquid by air can help to quickly get nutrients to crops in the middle of growing season, and has been specifically designed for ‘slow release’ and ‘high efficiency’ so the farmers are able to less fertilizer while achieving better outcomes.

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Rick James

I am an aviation nut! I'm an ATP-rated helicopter pilot & former flight instructor with over 3500 hours spanning 3 countries and many different flying jobs. I love aviation and everything about it. I use these articles to pass on cool facts and information to you whether you are a pilot or just love aviation too! If you want to know more about me, just click on my picture!

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