Plough and the stars: How satellites have become a farmer’s most important tool
06 March 2018
Earth observation systems are satellites that view the earth and send the images back to the planet to be used across a huge range of applications. There is a global archive of data stretching back now nearly 50 years. Currently, in Europe, the Earth observation platforms are under the control of the European Space Agency, with its most advanced fleet, the Sentinels, forming the backbone of the Copernicus programme.
Food production and finding new avenues in support of agriculture
One important target for Copernicus is food production and, increasingly, the space industry is finding new avenues in support of the agrifood sector.
Across the world, farmers are exploiting space infrastructure in order to maximise yields and reduce environmental impacts while maintaining regulatory standards, but much of the support the space industry gives to farmers is hidden.
For example, the weather reports and forecasts that farmers rely on depend on satellite imagery and space-borne sensors to collect the data so that the forecasts can be made.
Back on the farm, the Global Navigation Satellite Systems, like the American GPS or the European Galileo system, are used regularly. It could be a GPS in a tractor cab linked to farm maps that help guide the farmer with operating the harvest in the most efficient manner.
Already GPS enabled ‘smart tractors’ can operate largely autonomously
It could be the GPS on the smartphone enabling location-based apps that help a farmer map the farm or indemnify the current prices of the nearest cattle processor. Already, GPS enabled ‘smart tractors’ can operate largely autonomously, and the days of the driverless tractor is now a reality in some countries.
Virtual fencing depends on cattle being geotagged, with a GPS tracker and their movements monitored remotely.
However, it is the direct use of Earth observation data (satellite images) in agriculture that is having the biggest impact.
Space-based imagery is used every year in validating the European farm payment system. A percentage of farms are imaged with very high resolution multispectral satellite imagery and remotely inspected to validate that farming is going on in a manner that satisfies the accepted environmental standards.
Satellites can be used to remotely estimate yields
This imagery is more than just a pretty picture. Complex algorithms exploiting the relationship between reflected sunlight and the properties of the living crop mean that the satellites can be used to remotely estimate yields or measure the area planted or look to see how a crop is faring over a season.
The EU produces regular bulletins on European crop yields, but also regular bulletins on food security across Africa and the Far East, all from satellite observation.
Farmers themselves are getting in on the act and using satellite data and information derived from them to help manage and monitor their enterprises. This is a multi-billion-dollar industry and includes big player names such as Monsanto.
These precision agriculture farm management tools help maximise output, reduce inputs and be regulatorily compliant. The satellite imaging helps in identifying long-term persistent yield issues (for example, a section of field with drainage issues) but also can monitor a crop over a season and look for problems such as nutrient deficiency or pests before they are readily observable to the farmer.
Newer precision agriculture tools exploit the satellite imaging systems
These newer precision agriculture tools exploit the satellite imaging systems. They can be thought of as giant cameras in space recording continually as they orbit the earth. Some can only see on a broad scale, where each pixel represents a kilometre square on the ground but will capture an image every 15 minutes. Others image a given spot only every few weeks but record detail down to centimetre scales.
Once a farmer has a map showing subfield variation in performance, this data can be fed into the on-board systems on the ‘smart tractor’ and linked to control the machinery attached so that the farmer only sprays pesticide, for example, where the satellite has determined the pest infestation to be.
Why do farmers need help? Surely nobody knows the farm better than the farmer? While this is true, this does not mean that a farmer knows everything about their farm or has full knowledge of the current conditions. Remote sensing can give a different prospective on the farm.
Show a farmer how they are performing compared to the neighbours
Satellite systems that estimate grass yield, for instance, can show a farmer how they are performing compared with their neighbours. Measuring grass yield on every paddock every week, as is the recommended best practice, is a time-consuming process.
A satellite imaging system or a drone-based system that can produce a daily paddock scale map of grass cover – currently being researched within Teagasc – could have significant impacts on farm yields and on reducing a farmer’s workload.
In Ireland, European space agency satellites are being used to monitor soil moisture, grass growth, deforestation, peat lands exploitation and urbanisation. Research is continuing in using satellite data to help informed decision making, especially on the issues of grazing management, disease monitoring and nutrient planning.
And the use of drones on the farm is growing. Already they’re being used by the farmer for mapping farm layouts and, increasingly, for very high-resolution mapping of in-field heterogeneity. Drones are also being used for farm building inspection and general farm security.
Remote sensing systems valuable for policymakers too
Remote sensing systems and Earth observation methods are valuable for policymakers, too. Satellites can produce maps of farm habitats, for example, allowing policymakers to focus in on areas of high habitat value. Remote sensing is the only way to get regular updates on agricultural land use.
Space technology also plays a role in rural security; recent examples of upland fires and lowland floods across the country reveal how the European Space Agency emergency response system was activated and provided imagery of the affected areas, allowing for better targeting of emergency response assets.
The agency, through its Copernicus system, has invested billions of euro in Earth observation infrastructure – the data from the new constellation of Sentinel satellites is largely free and will form, in conjunction with the European Galileo positioning service, the data backbone for many new precision agriculture tools that Irish and European farms and contractors can use and build on to ensure sustainable agriculture.
Author: Stuart Green https://www.teagasc.ie/contact/staff-directory/g/stuart-green/
Stuart is a senior research officer in the Rural Economy & Development Programme at Teagasc and is the remote sensing specialist in the agribusiness and spatial analysis department at the Ashtown Research Centre, Dublin. He is interested in using terrestrial earth observation technologies to understand issues important to rural Ireland and Irish agriculture. He was a founder of the Irish Earth Observation Symposium, which recently held its 11th annual conference in Maynooth University.