Environmental Benefits

The aerial application industry consists of small businesses and pilots that use aircraft to aid farmers in producing a safe, affordable and abundant supply of food, fiber and bioenergy. Aerial applicators protect forestry and play an important role in protecting the public by combating mosquitoes carrying West Nile Virus, encephalitis and other diseases.

Some farmers apply their products from the ground using ground equipment, but many have realized that using an ag aircraft to do this work is often more efficient and effective. For example, manned aircraft can treat wet fields and spray when crop canopies are too thick for ground rigs. Unlike ground rigs, aerial application does not contribute to topsoil runoff or compact the soil. Moreover, when pests or disease threatens a crop, time is critical. At a minimum, an airplane or helicopter can accomplish three times as much application work as any other form of application can.

With all those benefits stated, the research that continues to accumulate most readily on aerial application’s benefits focuses on how it prevents runoff of essential topsoil and prevents soil compaction, which can result in a less-hospitable growing environment for a crop and reduce yields, nutrients and moisture. Higher yields are also due to aircraft treating above, not in, the crop canopy where ground rigs can trample a portion of the crop, ultimately reducing its yields.

Studies Underscoring Aerial Application’s Crop Yield Producing Advantages

• A Purdue University study shows ground applicator rigs damage approximately 1.5 to 5% of soybean crops.
• An analysis by Russ Gasper with the Nebraska Department of Aeronautics calculates a significant corn yield boost using ag aircraft. Using the aforementioned Purdue University study, Gasper used the same assumptions with corn damage in Nebraska and found that it costs the state nearly 6.37 million bushels of corn or approximately $34 million in economic activity annually.
• A joint 2008 American Society of Agricultural and Biological Engineers study conducted by Drs. Bob Wolf of Kansas State University and Scott Bretthauer of the University of Illinois shows an 18.6 bushel-per-acre yield increase in corn treated with an aerial fungicide application compared with untreated corn.
• Another strong piece of academic evidence favoring aerial application stems from the University of Minnesota Extension’s website, which has collected an assortment of research indicating soil compaction from ground rigs can negatively affect crop yields. The conclusions made are that a moderate amount of compaction is desirable at seed time; however, too much under dry conditions can be detrimental to yield and under wet conditions any amount of compaction can decrease yields, as it results in nitrogen loss, reduced potassium availability and inhibition of root respiration due to reduced soil aeration. In addition, excessive compaction decreases water infiltration and storage and decreases root growth.

The speed and efficacy of aerial application are why it is a critical part of agricultural production in the U.S. and why aerial application is part of the solution to tackling climate change. There are four significant ways aerial applications reduce greenhouse gases and improve the climate.

Combating Climate Change through Aerial Application

1. Preserving Land

Aerial application plays a key role in maximizing yield on existing farmland and reducing the need to convert more land into cropland. Research conducted by Senarath Dharmasena Ph.D., Assistant Professor with Texas A&M University’s Department of Agricultural Economics, shows the importance of aerial application for higher yield agriculture for major crops in the U.S. His research, presented at the 2020 Ag Aviation Expo in Savannah, Georgia, looked at five crops: corn, wheat, cotton, soybeans and rice.

Dr. Dharmasena calculated the reduction in yield for each crop that would occur if aerial application was not available. Using data from the 2019 NAAA industry survey, it was determined that the aerial application industry is directly responsible for the production of 1.69 billion bushels of corn, 199 million bushels of wheat, 548 million pounds of cotton, 295 million bushels of soybean, and 3.33 billion pounds of rice annually that would be lost every year without the aerial application of pesticides. The total area of cropland needed to replace this lost yield is 27.4 million acres, an area roughly the size of Tennessee. This research covered only five crops, so it does not fully account for the 127 million acres treated by aerial application annually. Therefore, aerial application protects at least 27.4 million acres from being converted into cropland every year.

2. Increasing Pesticide Efficiency

Dr. Dharmasena applied an average yield reduction of 25% when aerial application is replaced by ground application. This is in part due to the precision and efficacy of aerial application, as demonstrated with the yield differences referenced earlier, and greater productivity of aerial applications. Aerial applications can be made in a timelier manner than ground applications because of their ability to spray when the ground is wet and cover more ground in less time than a ground sprayer.

The productivity of aerial applications also plays a crucial role in managing pesticide resistance. All pesticides have a window when they are most effective on the targeted pest. Applications made after this window passes dramatically decrease the effectiveness of the pesticide, which can result in reduced yield and additional applications to attempt to control escaped pests. It can also speed up the development of resistance to additional types of pesticides.

To compare the productivity between aerial application and ground application in a row crop agricultural setting, an aerial applicator and ground applicator from Mississippi were asked to provide details about the productivity of their application equipment. The aircraft was an Air Tractor AT-502B with a 60-foot swath width, and the ground rig was a John Deere R4030 with a 90-foot boom. During an average 12-hour day, the aircraft treats 1,800 acres while the ground rig treats 450 acres, meaning aerial application is roughly four times as productive as ground application.

The greater productivity and efficacy of aerial applications result in greater pesticide efficiency. Graham Brookes and Peter Barfoot concluded that greater efficiency with pesticides helps farmers adopt reduced tillage production systems, which Bruner et al. show could reduce an additional 17.7 million metric tons of carbon equivalent annually if 25% of intensive or reduced tillage acres were converted to strip tillage or no-till soil management practices. Such a conversion would be equivalent to removing greenhouse gasses released by 3.8 million cars driven for a year.

3. Enhancing Cover Crops

One of the most promising conservation practices aerial applicators can assist farmers with is cover crops. Cover crops are grasses, legumes, small grains and other low-maintenance crops planted specifically to improve soil health and biodiversity. By sowing the seeds aerially with a preharvest cover crop application, cover crops control erosion, retain and recycle soil nutrients, build organic matter to improve soil health, enhance water quality and moisture availability, and break disease and insect cycles.

Growing cover crops is a way that agricultural production can increase soil carbon sequestration, which involves removing and storing carbon dioxide from the atmosphere. The average emission reduction coefficient (ERC) for cover crops grown in cool temperate moist and warm temperate moist zones reported in Bruner et al.’s study “Combatting Climate Change on US Cropland: Affirming the Technical Capacity of Cover Cropping and No-Till to Sequester Carbon and Reduce Greenhouse Gas Emissions” is 0.495 metric tons of CO2 per acre per year. Data from the 2019 NAAA industry survey shows that aerial applicators seed 3.8 million acres of cover crops annually. This means that aerial applicators are responsible for helping to sequester 1.9 million metric tons of CO2 equivalent annually, which, according to the EPA, would be the equivalent of removing approximately 412,000 cars with carbon-combustion engines from the roads each year.

The Bruner et al. analysis further found that if cover crops were grown on an additional 15% of available U.S. cropland acres, there would be an additional reduction of 11.9 million metric tons of carbon equivalent—or the equivalent of removing from the roads annually approximately 2.6 million cars with carbon-combustion engines. Aerial application will play a key role in increasing the acres of cover crop grown. While there are several methods of seeding cover crops, aerial application is the most effective means of applying cover crops successfully. The best time to apply many cover crops is when the harvestable cash crop is still standing. Aerial application offers the ability to spread the cover crop seed over the existing crop without disrupting the standing crop. This means the cover crop can already be established when the cash crop is harvested. Aerial application can also be used when the soil is wet and can seed many acres quickly. The Soil Health Partnership recognizes that aerial application’s ability to apply seed earlier in the year results in better growth and overwintering of cover crops. Michigan State University Extension also recognizes that aerial application is a good option for applying cover crops.

4. Precision Agriculture

Precision agriculture improves the accuracy and efficiency of all facets of agriculture and is heavily utilized in aerial applications. Precision agriculture technologies aerial applicators use include Global Positioning System (GPS) units, more effective nozzles and boom-lowering systems that position nozzles in less-disturbed air for improved application accuracy. According to NAAA’s most recent aerial application survey in 2019, 99.9% of aerial applicators use a high-tech navigational GPS to ensure a targeted application and also aid to prevent overspray, drift and unintended exposure to people or the environment.

Innovative technology exists that combines GPS, GIS based prescription maps and the variable rate flow controller to allow the product to be applied in varying dosages according to what the condition needs are in the field and targeting the material to be delivered only where it’s needed. This enables less product to be used, covering more acres, resulting in less potential for drift and less fuel used, both of which benefit the environment. Aerial applicators make liquid and dry variable rate applications to ensure pesticides, nutrients and seeds are applied at the precise rate needed in each section of a field.

Because it is the responsibility of the agricultural aircraft operator to be aware of sensitive areas when applying products, the majority of ag aircraft are also equipped with smokers. Smokers enable pilots to safely inject a small amount of vegetable oil into the aircraft exhaust system that results in smoke being created, allowing the pilot to determine, as the smoke moves in the atmosphere, the wind direction and an estimate of wind speed.

Another precision application system being used by ag aviators to ensure more targeted and efficient applications of crop protection products is the Aircraft Integrated Meteorological Measurement System, also known as AIMMS. AIMMS adds an additional layer to the precision ag system by incorporating a real-time onboard wind speed and direction measurement system. The atmospheric data collected by AIMMS is then synchronized with the GPS unit and GIS Software. This enables the variable rate flow controller to apply the product, factoring outside wind speed and direction, resulting in an even more precise application. Additional information on the precision application technologies used by aerial applicators can be found in the Fall 2018 issue of Agricultural Aviation.