Category: Agriculture

01 Mar 2019
Greener Grass for grazing event

Greener Grass For Grazing

On the evening of the 28th February 2019 we attended the Getting Greener Grass event organised by the Soil Association Scotland. The speaker for the evening was Andre Van Barneveld of Graise Consultancy. The focus of the evening was managing grass growth for grazing of sheep and cattle. Our primary interest was identifying issues farm drones can solve in delivering aerial mapping information.

Having attended a few of the Monitor Farm events local to East Lothian we are beginning to build up a picture of the issues effecting farmers. Soil quality is the predetermining factor of any crop, be it grass, cereals or vegetables. There will be variation across any field or between farms based on their rotation schedule, soil type and subsoil structure. Soil sampling can identify the state of all the key elements such as organic matter, pH, N, P and K levels. Action can then be taken prior to growing season to top up these levels. Farm drones have little use at this stage untill the soil sampling stage is automated that is. However, aerial farm drones still provide a useful tool to quickly identify areas with issues to resample during the growing season.

Secondary environmental issues to any crop are soil temperature, sun and water. Too much or too little of each can have a dramatic effect or yield and risk disease. These issues are unpredictable year on year and subject to regional variation.

Lets Get Going

For grass and crops the primary growth accelerant in initial stages the application of Nitrogen. Farm drones can’t provide an exact application amount but they can provide a highly detailed application map. This is of greater accuracy than soil mapping that relies on sample averaging over the field.

Graise consultancy greener grass
Graise consultancy greener grass

Drug Addicts

For grazing Andre made some interesting points on the use of Nitrogen that plants can become drug addicts relying on supplements rather than converting it themselves from the soil. For grass such stress can bring forward seeding early. We would make an argument for the closer inspection of grass and crops using multispectral imaging.

For the rotation of grazing paddocks there is opportunity for farming drones. Andre pointed out several times in his presentation the need to keep grass grazing in its sweet spot in terms of length 4cm. Too little grazing and grass will become taller and grazing or cutting at this height will place stress on the root to re-tiller the lower portion of stem. Animals will less likely graze on longer material and place stress on the more tender shoots by eating those. Alternatively, over grazing will minimised leaf size to a point where too little sun light is absorbed making it less nutritious and also damaging plants to the stage ground becomes muddy and rutted.

Andre advised having 20 day rolling paddocks. We think that farm drones could be useful here to identify when a paddock has reached its ideal grazed off level and the flock/herd should be moved to the next. The level will be determined by all the factors above, and so by the type, size and number of animals feeding across the area.

Skytech Aerial are now looking for farm partnerships to develop our technology further. More details of our agricultural monitoring services can be found here. If you would like a demonstration on how drone imaging can help your business please contact us today.

24 Sep 2018
Wheat multispec

Multispectral Data for Agriculture 2018

This year we have been working with a few local farms creating agricultural maps using drones to assess plant health and assist variable rate application of fertiliser, herbicide and pesticides. Using a modified Phantom 3 drone with the Parrot Sequoia multispectral camera we successfully performed dozens of missions this summer on a variety of crops. Some examples are shown below processed using Pix4D and the ATLAS platform from micasense.

Slug damage and another issue
Top: Wheat slug damage over winter. Bottom: Potatoes with some compaction lines and density variation.

Variation in results for NDVI and NDRE for potatoes.
Variation in results for NDVI and NDRE for potatoes.

Variation between NDVI and NDRE for wheat.
Variation between NDVI and NDRE for wheat.

One of the biggest problems we faced was presenting this data in a reliable GIS software. Most of the solutions currently lack features and only do one thing very well. For example ATLAS from Micasense is a far superior visualisation tool than Pix4D but it cannot create variable application zones for tractor shape files.

Towards the end of the season we purchased a Sentera 4K Double Multispec camera which has some interesting features over the current multispectral cameras on the market. In particular it has a higher resolution camera, is very compact with only two lenses and comes with a DJI compatible gimbal. This means more reliable stitching as the camera is always NADIR (looking straight down) where the P3 or fixed wings will capture slightly angled images depending on wind.

Over satellite imagery aerial imagery from drones provide far greater resolution. For example ESA Sentinel-2 has ground resolution down to 10m only and updates every 10 days which might or not be cloud free. A drone at 100m with the Parrot Sequoia camera provides GSD of 10cm and for the Sentera 4K 3.5cm, regardless of cloud cover.
There is certainly room for both approaches in farming, for analytical strength aerial imagery outperforms satellite. We look forward to sharing more imagery captured soon.

09 May 2017
Phantom 3 AG

Agricultural Monitoring Trials

We’ve been refining our agricultural monitoring service which we will offer to farmers in Scotland and Northern England in the next few weeks. We have combined the MicaSense Sequoia Multispectral camera with a modified UAV for data collection. Using the Pix4D Mapper Pro software we can now produce high quality field data to supplement modern precision agriculture.

Currently there are several NDVI survey cameras on the market but many of these lack features and require difficult post processing to calibrate and geotag the resulting images. The Sequoia camera provides an all in one solution and integrates seamlessly with Pix4D Mapper Pro.

Phantom 3 AG
Skytech Aerial Phantom 3 AG In Flight.

This light weight camera made it possible for us to modify a DJI Phantom 3 drone to carry it. Over larger UAV platforms the smaller Phantom class is light and efficient to fly as well as easily transportable when walking a long way over rough ground. We’ve flown hundreds of acres so far in our trials and it’s proven capable of capturing the imagery required for agricultural mapping.

Once we have acquired imagery data from the field it is processed using Pix4D Mapper Pro a professional mapping software that calibrates, combines and indexes thousands of images to create an indexed field map. By combining different light spectral bands red edge (RE) and near infra red (NIR).

Vegetation Reflectance Bands
Vegetation Reflectance Bands

The principle of NDVI analysis is that a healthy plant reflects more NIR than an unhealthy plant. Plants may look green but the RE and NIR bands of interest are unseen to the human eye. These along with RGB colour values may be added to different indices formulas to provide a plant health indicator.

Pix4D AG
Screenshot of Pix4D Mapper Pro showing the stressed areas in red.

The indexed map colour then gives a plant ‘health’ indicator from green for healthy plants, through to red for stressed plants. This data can be used to create an ‘agricultural prescription’ which is simply an application map file readable by modern farm equipment so that they can spray the correct amount of fertiliser or pesticide in the marked areas.

This health report can then be used along with farm based data (what, when has happened already) as well as point inspections to diagnose the problem (pest, nutrition, irrigation).

Further examples follow:

Example 1
Example 1

Example 2
Example 2