Using Agricultural Drones

Agriculture drones offer farmers the potential for addressing several major challenges. Drones help farmers optimize inputs (seed, fertilizer, chemicals), react faster and more efficiently to pests (weeds, insects, diseases), save time scouting, improve variable rate applications, and estimate yields. They are fast, reliable, fairly inexpensive compared to traditional machinery, and can give very precise information instantly. Drones help farmers from planting through harvest.

Drones are being used in several major ways. First, small drones analyze crop fields for soil analysis. Drones provide 3-Dimensional (3D) maps of fields which help farmers with planting decisions and fertilizer needs. Drones monitor crops in real time and can identify crop nutrient deficiencies which can be corrected quickly before crop yields decline. Crop sensors are good at identifying nitrogen and water deficiencies in a crop field, especially where irrigation is used extensively.

Drones are even being used to plant some small seeded crops, especially cover crops. With the current limit of 55 pounds, large seeds are not economical yet. However, the legal limit may be increased to 450 pounds in the near future, which will greatly increase drone usage. Drones this spring were being used to apply red clover to wheat, hairy vetch and lupins to cereal rye, and last fall cover crops; crimson clover, Balansa clover, oats, radish, rape, and kale. One local drone applicator applied 3500 acres, another close to 10,000 acres (seed, fungicides, herbicides). Both applicators are planning to increase their acreage by a factor of 3X using multiple drones this year.

Agricultural drones are being used extensively is for crop spraying. Herbicides to kill weeds, fungicides for disease control, insecticides for insects, and foliar feeds for micronutrients applications are becoming common. Large applications for lime, nitrogen, phosphorus, and potassium are limited because the pay loads are too small until larger drones become legal. Drones can cheaply and quickly monitor crops, quickly spray the crops, and then monitor the crop response to the applications which improves crop growing efficiency.

Drones have numerous sensors including cameras, visible light, infra-red sensors, and distance measuring equipment called LIDAR which helps the drone sense the topography and sensors that help it avoid buildings, electrical poles, trees, and other obstacles. Drones can scan the ground and spray the appropriate amount of liquid to give even coverage or even variable rate coverage on the fly. This saves the famer money by reducing input costs and may even improve water quality by using less chemicals.

Drones have proven to be better than satellites when it comes to crop monitoring. Satellites are more expensive, the data has to be down loaded, usually they pass by 1X per day, and clouds can obscure the vision. Drones can be limited by high winds and hard driving rains, but they are more flexible in gathering data instantly, they are cheaper, faster, reliable, and more precise than satellites.

For disease and crop health assessments, drones identify fungal or bacteria diseases quite easily. Most drones hover from 20 feet to 160 feet above the crop canopy. Using the difference in visual light compared to infra-red light, they monitor plant health throughout the growing season. Drones can compute vegetation indexes, crop density, and crop height which is used to estimate crop yields. For insurance purposes, they can document yield losses or yield gains from different types of management.

For irrigation, drones use thermal sensors and multispectral imagers to estimate moisture deficiency. Using the right amount of irrigation water reduces costs and saves water, especially in dry regions using water from dwindling aquifers. Drones use much less fuel and most use electrical batteries compared to traditional farm equipment. Another advantage is reduced soil compaction and less crop damage, since they are flying over the crop rather than traveling through it.

Most drone experts say drones are up to 5X more efficient and faster at applying inputs (seed, fertilizer, sprays, chemicals) than traditional farm equipment. By using variable rate technology and sensors, they can use inputs only where they are needed, reducing costs. Recently on 40 acres, it cost $14 per acre to apply cover crop seed (red clover) to wheat compared to at least $20/acre for an airplane and it took only 2.5 hours.

The future of drones looks bright. New regulations, better cameras, and more sensors are needed, but drones are starting to become a more common sight on farms. The cost varies but $1500 to $4500 is a common cost for a drone that applies farm inputs (seed, fertilizer, chemicals) with some larger and more sophisticated agricultural drones costing over $20,000. However, drones are highly regulated and require FAA licenses to operate. Compared to other farm costs, drones are fairly inexpensive.