Breezy Hill Ag
How we used NDVI satellite imagery to pinpoint frost damage for strategic harvesting
Introduction
Breezy Hill Ag is a multi-generation farming business focused on cropping and fine wool merinos. The farming enterprise consists of Joe and Jess (me) in combination with Robert and Joyleen (Joe Parents) operating around Booleroo Centre and Georgetown.
In 2018, Joe and I saw an opening to branch out as we have a keen interest in precision mapping and what it could do for our business, so we started Breezy Hill Precision Ag Services. Collecting meaningful data and continually analysing cause and effect of spatial variability in our crops is something that Joe and I are passionate about as we believe we can make a difference in our management with knowledge, and we were right.
Challenge
During the harvest of 2017, Joe spotted frosted peas in our central part of the paddock, at the start of sandy rise. Upon inspection, it was discovered that they had 'shot out' as some green foliage was visible in amongst the golden canopy.
Joe decided to reap a sample of peas, as he wanted a confirmation that they we're frosted. Upon sending a sample to the grain receival's site, his suspicion was proven correct.
The grain receival's identified that the percentage of defective grain in the sample was too high, this meant that our pea harvest would not pass delivery standards. In essence, this meant lost profit for Joe and I.
As a mixed enterprise, we have the option to feed frost effected grain to our second half of the business, our merinos. But knowing that our entire crop wasn't frosted, we wanted to use data to pinpoint the frost affected areas ONLY so we weren't feeding our high quality deliverable grain to our sheep. Instead we could deliver this grain as a cash crop and make this paddock profitable.
Solution
The PCT AgCloud software allows you to download Sentinel satellite imagery, which can be current or historical, based on what you need at the time. It is an indicator of biomass and crop colour.
With this knowledge in mind, Joe asked me to download an NDVI (SVI) image from earlier in October, the frosted area of the field showed up blue/green, and the rest of the field showed up red (as it should).
We both agreed that it was an accurate representation of the frost effected area. With this knowledge combined with the grain sample results, gave us confidence that the best way forward was to harvest the frosted area in isolation, and we would use the blue/green area in the NDVI image as an indicator of where we'll need to harvest.
I created an internal boundary around the blue/green area which Joe was then able to upload straight into his steering console in the header.
Benefits
One of the applications of the PCT AgCloud software, is that it can produce NDVI (SVI) maps. The most powerful aspect of these maps is that if you were to sign up with Breezy Hill Precision Ag Services today, we could instantly recall satellite imagery from a number of years back. You'll able able to gain an insight into your crop variability from any moment in the last 7 years. ALL of these maps will be available to view from your AgCloud account every 7 to 10 days as the satellite fly's over.
Satellite imagery is a great starting point to create paddock scale solutions. If you were to combine this spatial data with agronomic knowledge (in this case paddock inspection results and grain recieval results) this is where the 'magic' happens.
With this combination of information, you're able to segregate different management zones, and define the most profitable pieces of your crop very simply and easily year after year.
Results
In our case, the NDVI map was a very accurate indicator of the frost effected boundary. Without this map layer we would have had no geo-referenced indicator of where the frost damage started and ended.
As a result, both Joe and I were confident to not only, harvest the isolated area of frost, but generate the best gross margin per hectare. Joe then used this internal boundary generated from the NDVI zone as a guide line to harvest the frost affected area, making us $8,000 of profit which would otherwise have been utilised as stock feed.