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Precision Agriculture – A case study on crop scouting


Precision agriculture, and crop scouting in particular, has taken off via the the use of drone technology.  Expect this to continue through 2015.

Our friends at Event 38 first wrote this article on crop scouting in August of 2014.  However, the information is so valuable that we decided we would share it with you now.

Precision Agriculture
Through recent advancements in drone technology, the cost of collecting vast amounts of information on large areas of land has decreased to pennies per acre. New, sophisticated sensors let us gather data at the plant (leaf) level at a moment’s notice, which supports speedy decision-making and an opportunity for farmers to attain higher crop yields. By adding additional data sources, we expect to find hidden relationships and make further improvements in farm management. This combination of drones, sophisticated sensor hardware, and big data predictive and prescriptive analytics will revolutionize farm management in the near future.

Crop Scouts
Crop scouting is a key service to farmers to ensure crop success. Typically, they are engaged to identify crop issues, (i.e., pests, soil condition, disease, plant health, weeds, etc.) and to make recommendations for treatments/interventions. Currently, they periodically sample small areas and generalize their findings to the whole field. In the near future, crop scouts will use drones to analyze the complete planting area, quickly identify issues, and provide recommendations for highly localized treatments.

Crop Scouting Case Study Results
Today we can gain basic insights about the crop. In the future we will be able to identify and quantify specific issues, allowing the farm manager to take measured action only when financially appropriate.

Today Tomorrow
  1. Spotlight areas of interest for ground investigation
  2. Determine crop height and growth
  3. Calculate crop health with NDVI
  1. Spot certain insects, diseases, weeds and pests
  2. Determine economic intervention threshold levels
  3. Count livestock and determine grazing land health
  4. Time series and predictive analytics

In late-July, 2014, we flew over a 75-acre cornfield in central Ohio. The flight lasted about 15 minutes, was flown at 400 feet completely autonomously, and captured 140 images at a 3cm/pixel resolution.

Below are some of the findings we observed.

1. Spotlight Areas of Interest
By viewing the whole planting area, crop scouting is able to identify particular areas of interest to follow up with an examination on the ground.

Figure 1A Flyover at 400ft
Anomalous patches of bare soil visible from the air.Fig1A
Figure 1B 3cm Resolution
A more detailed view of a square shaped depression on the right side of Fig 1A, with stronger growth on one edge.1b
Figure 1C
A section of a field that shows unusual growth between rows.1c
Figure 1D
A more detailed view of the growth out of rows that most likely indicates the presence of weeds.1d

2. Determine Crop Height
Today we can sample the planting area to determine plant height. Taking periodic readings of the same area will give crop scouting an indication of plant growth over time.

Figure 2A
A cross section selection of the corn field.2A
Figure 2B
The elevation through the cross section shows the corn to be approximately 8 feet tall. 2B
In another area of the field, we identified problems with compaction or tractor damage. We can see dips in the plant height from the air if we look at a cross section of plants across a tractor track. This shows about a 1 foot difference in height. This result can be used later to help determine economic thresholds for late stage spraying.

3. Calculate Crop Health with NDVI

NDVI (Normalized Difference Vegetation Index) is a simple analytical tool that indicates chlorophyll activity in plants but is also strongly correlated to plant biomass, leaf area index, and plant stress symptoms.

Figure 3A The NDVI calculation shows no plant growth at all in many of these rows, after a late application of herbicide.
3AFigure 3C The patch below appears to be either a very infertile soil or just too wet to grow anything.
Figure 3B
The area at the top of this view appears to be growing very well compared with the rest of the field. The hill appears to be sloping down into the grass waterway, with the strong growth happening on the uphill side and weaker or average growth on the downhill side of the waterway. The same thing happens again a little further downhill at the edge of the field just 25-35 yards away and the same effect is not present in other areas that receive similar sunlight at low angles.3B

Event38 is working with crop scouting professionals and researchers to develop next generation tools for precision agriculture. We are actively seeking collaboration with farmers, researchers, developers, and commercial partners. Your comments and feedback are appreciated. Tell us about improvements you would like to see in the near future.

About Event38

Formed in 2011, Event 38 designs and manufactures two types of drones (fixed wing and hexa-copter) and specialized optical sensors. Today we have customers in 49 countries using our equipment for agriculture, surveying, construction, environmental preservation, and other applications.

Our current market focus is on solutions for agriculture. Our goal is to collect and aggregate all data relevant to cultivation, make it available to farmers, and to build a marketplace via an open architecture platform for ourselves and third parties to develop end user applications. For more information please contact us at www.Event38.com.

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