Satellite imagery has been used in agriculture for decades, but in recent years it has become more popular with the launch of new satellites by the European Space Agency that are helpfully designed for agricultural monitoring. This has made the data more frequent and allowed companies to develop applications and services that make it easier for agronomists and farmers to access and use the imagery.
This article will draw on a Twitter poll I ran last year that asked “If in agriculture, Where do you find most value with satellite imagery?”. I provided three response options based on my own experiences and asked participants to comment with further answers. To be clear, this article focuses on production side – that is farmers and agronomists, not grain marketing, regional crop forecasting etc. Farmers could use satellite imagery for grain marketing too, but that’s another topic.
The four poll options with outcome were:
- In the field scouting – 20.6%
- In the office, scout prep – 39.4%
- Input rates, Variable Rate Application – 33.1%
- Other – 6.9%
Let’s talk a bit more about each application remembering the poll question was framed around value.
- In field scouting – I take this as having your device with you when out inspecting crops. One example might be visiting paddocks on a routine basis. When arriving in field, using GPS location on an NDVI map of the paddock, see if the area you are inspecting is representative of the rest of the paddock.
- In the office, scout prep – Planning where you will go when out in the field before you get there. It makes a lot of sense to take a birds eye view of what is happing on the ground before you arrive. You can then target your inspections depending on crop type crop stage. For example, making sure you target high and low biomass areas of the field as the higher biomass areas may be more susceptible to insect attacks earlier. Preparing in the office gives you the added advantage of having access to other information that would be good to know when in the field such as rainfall distributions, crop rotation and yield history.
- Input rates which include variable rate application – This is taking the satellite imagery data and using it to apply input rates differently based on the data or some sort of derivative. This could include fertilizer or herbicides. Most new machinery is capable of this. It is interesting that this answer only took in 33% of responses. Maybe the audience is biased, or it could just be that the less technical applications of satellite imagery may just add more value.
- Other – A review of the comments sees discussion relating to harvest decisions, monitoring field trials, and inspecting historical development of the land.
It’s interesting to see the breakdown of the responses here and consider if people obtain most value in part because of the success and limitations of the tools available to and put in front of them. For example, when Agworld added a frequently update imagery layer suddenly many more people were now able to see variability within their fields that they may have not otherwise noticed. Now every Agworld subscriber had access to in office and in field satellite imagery to some degree and could ascertain it’s usefulness.
Many ag professionals are seeking out the next way to improve the service they provide, or the operation they manage and satellite imagery is a natural fit that leaves them wanting more.
Reframing the categories
Thinking further about applications of satellite imagery for agricultural professionals, it can probably be reframed in a more helpful way to these four categories:
- Enhancing human productivity
- Monitoring & benchmarking
- Optimising Input allocation
- Historical & land management applications
Clearly there is still some overlaps here. But lets look at each more closely:
1. Enhancing human productivity
As humans, we want to be as efficient as possible. Imagery enables this with the infield and in office scouting. Agronomists can make their inspections more targeted. It costs a lot to have humans on the ground, so they should be sent to where they are needed most. Improving the toolset to do this job can further increase productivity.
2. Monitoring and benchmarking
Sometimes you can monitor change better from space than humans on the ground, especially consistently over a large area. Many satellite sensors are always on capturing and archiving what they ‘see’ even if you have not planned it to be so. Understanding crop variability, comparing to previous crops in the same field and same season crops in different fields allows for much better management outcomes and better-informed decision making. The harvest timing mentioned above fits in here as does inter-season anomalies (e.g. this area usually performs very well but is falling behind this year). An added advantage is that the data is stored in raw formats so as spectral indices improve you can go back in time and apply better algorithms to old imagery. Monitoring includes fallow management as well such as weed infestations.
3. Optimise input allocation
This brings us back to the variable rate chemical and fertilizer application. There are many examples where satellite imagery has been used on it’s own, but more frequently with other data sources to better allocate fertilizer to either even out yields or get best return on investment. This could be using a simple vegetation index such as NDVI or using soil color as a proxy representing some soil characteristic.
4. Historical & land management applications
With archives going back well into the 80s, satellite imagery is very useful for understanding the history of the land. For example, sometimes variability within a paddock can be attributed to multiple paddocks with different histories being combined into a single paddock. Other applications here are investigating the movement of flood water, researching potential property purchases and spotting where neighboring drift risks are.
This article has taken a quick Twitter poll and given me pause to think about how agricultural professionals apply satellite imagery in their businesses. I have come up with four categories that I think most specific use cases can fall into. It’s good to think about this because it shapes how we think about committing time to exploring satellite imagery as a tool to increase the overall profitability of your business. An example mindset change could be: Don’t dismiss satellite imagery because you think variable rate won’t work on your farm or for your clients. Much of the value in satellite imagery is in the enhancement of human productivity. The converse is, satellite imagery can’t solve all your problems so don’t dive in blinded by hype.