Unmanned Aerial Vehicles

In-field Conservation


In-field Conservation

UAV Benefits

  • Quickly evaluate the impact of implemented conservation practices
  • Map conservation structures and retain photographic record of performance. over time
  • Quickly identify conservation system issues at a large scale in order to manage and mitigate environmental impacts
  • Obtain photographic documentation of conservation field practices

UAV Challenges

Timing: Flying conservation systems, specifically cover crops, is done primarily outside of the growing season and requires time usually not spent in the field.

  • Tip: Knowing when to fly in the fall, winter and spring is important. The best time to fly is with little to no other vegetation growing.

Clouds: Broken skies can ruin image quality.

  • Tip: Fly when skies are fully overcast or clear for optimal image quality.

Camera settings: Incorrect settings can affect image quality.

  • Tip: It takes a little experience. Familiarize yourself with general camera settings and know the goals of each particular flight.

Examples

Prevent plant cover crop performance

Flown by Austin Pearson, Agriculture & Natural Resource Educator, Purdue Extension – Tipton County

In 2019, this producer took preventative planting due to wet spring conditions. Cereal rye was planted as a cover crop in fall 2018, so the producer decided to map the field for cover crop performance. The maps were also used to plan the installation of subsurface drainage. A still photo for a natural overview.

Cereal Rye for tile_Still

The green areas indicate a healthy cover crop and the red shows areas drowned out by rain.

rye RGB
rye VARI

Conventional vs. cover crop in soybeans

Flown by John Scott, Digital Agriculture Extension Coordinator, Purdue Extension

These flights evaluate conventional management with no-till cover crop management. The field on the left uses cereal rye as a cover with 30-inch soybean rows planted into the cover. The field on the right was tilled without cover crops and planted in 15-inch rows.

It’s evident the no-till field has more bare spots which can attribute to vertebrate pest damage.

RGB: Orthomosaic
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Sub-Area 1
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Sub-Area 2
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VARI: Plant health
SoyCover_Conventional_VARI

Cover crop planting method comparison

Flown by John Scott, Digital Agriculture Extension Coordinator, Purdue Extension

Different cover crop application methods and timing of those applications were evaluated at Ivy Tech in Lafayette, IN. Cover crop treatments are highlighted from right to left which corresponds to planting time. The cereal rye and hairy vetch cover crops on the right side of the image was interseeded into corn at a growth stage of about V4-V5 in June. The cover crop in the second section from the right was seeded using the DJI Agras at a rate of 70 pounds of cereal rye per acre in mid-September. Half of the plot was a cereal rye and hairy vetch mixture, and the other half was cereal rye and crimson clover. The next section was not planted with any cover crop and winter annuals can be seen in the image. The last section on the left was drilled with cereal rye and hairy vetch immediately after harvest (late October). The UAV applied cover crop did not produce more biomass than the interseeded plot on the far right but was superior to the post-harvest planting.

SidebySide2

Giant ragweed in cover crops

Flown by John Scott, Digital Agriculture Extension Coordinator, Purdue Extension
Field visit with Joe Rorick, Agronomist, Conservation Cropping Systems Initiative

In addition to the cover crop comparison above, some strips of cereal rye/hairy vetch were planted to evaluate the effects against next year’s crop. This field was previously planted in corn and going to soybeans. Cover crop was interseeded into the corn about V4-V5 in June. The overhead image shows the cover crop in early May prior to termination and soybean planting. It is possible to clearly see the green strips of cover crop and some areas of weeds. This field traditionally struggles with Giant Ragweed.

The ground-based image shows the difference between the cover crop and untreated strips even more clearly and shows the height of the cover crop. The untreated is on the left-side of the image and the cover crop on the right. The image taken on the tailgate shows Giant Ragweed samples collected from strips with cover crop (right) and those untreated, without cover crops (left). The plants from the untreated are healthier, greener plants while the weeds from the cover crop strips are struggling likely due to competition for resources from the cereal rye.

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tailgate

Preliminary cover crop data collection to serve as a performance model

Flown by John Scott, Digital Agriculture Extension Coordinator, Purdue Extension

The map below was created a few days after spring termination of the cover crop. Treatments consisted of several different cover crop mixtures, as well as no cover. The field was then planted to corn with different rates of starter, including no starter, and taken to yield. Flights were conducted in the fall and up until late December before resuming in March. By doing this, the cover crop establishment and growth was monitored with the goal to correlate the aerial images with ground-based measurements and create a model for measuring cover crop performance.

CoverCrop

Cover crop interseed demonstration

Flown by Jon Charlesworth, Agriculture & Natural Resources Educator, 4-H Youth Development, Purdue Extension - Benton/Warren County 

A local producer wanted to interseed cover crops at planting time to maximize benefits and was curious how it would impact the cash crop (in this case corn). This demonstration was only a small block of a larger field so the stand could be evaluated quickly and limit any adverse risk to the corn. The plot was flown to see how well the cover crop was performing a couple times during the season. The cover crop did well, flourishing after maturity of the corn and the corn performed well.

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Drone cover crop seeding

Flown by Curt Emmanuel, Agriculture & Natural Resources Educator, Purdue Extension - Boone County; John Scott, Digital Agriculture Extension Coordinator, Purdue Extension

A DJI Agras was used to spread cover crops over standing soybeans. Cover crop mixes varied and were compared against the same mixes drilled after harvest. Several demonstrations are planned across the state using the UAV to spread cover crops and evaluate spread patterns, and seeding rates and compare against other seeding methods.

Grassed waterway management

Flown by Jon Charlesworth, Agriculture & Natural Resources Educator, 4-H Youth Development, Purdue Extension - Benton/Warren County 

Stitching software can measure the depth of a grassed waterway to determine both water capacity and compliance within a Conservation Reserve Program (CRP). The graph on the left shows a shift in the elevation profile. The spike in elevation could have been caused by ground cover or inaccuracy of initial GPS points. We later determined weeds were the cause, which we validated from the ground. The use of a UAV for this type of management practice does not replace traditional boots-on-the-ground methods; however, it greatly reduces time and labor.

Grassed waterway

Here are views of three water and sediment control basin (WASCOB) structures, each containing two to three basins. A WASCOB is designed to control water runoff after a rain. Each structure has a subsurface drainage system at the lowest point of the basin where the water pools. Once the water reaches the top of the drainage system, it is discharged through the main tile system. Any sediment in the water settles to the bottom of the basin, which prevents permanent erosion and reduces pollution in other water bodies.

The elevation profile on the left of the image above makes it possible to see overall hillslope as well as each individual berm.

WASCOB
Down Upright

The image below shows a subsurface drainage structure knocked over, most likely due to flooding. It was not functioning and needed repair.

Flooded grass waterway

Water standing in this newly installed grassed waterway (above) indicates a problem. While several issues could be at fault, an exact determination requires someone to closely examine the tile However, the UAV is a good tool to offer a snapshot of performance to conservationists.