When to harvest is one of the most crucial decisions a wine producer can make. Too early, and the result is bitter. Too late, and it is overly sweet. It’s a delicate balance, and one that is increasingly being upended by the climate crisis.
In France, global warming has been wreaking havoc on this ancient formula for some time. Wine growing regions across the country have seen seasons truncated: for example, the harvest date in the Châteauneuf-du-Pape appellation, one of the most prized, has moved up almost three weeks since 1960. At the same time, plant diseases are appearing in regions that have never seen them before, rain patterns are changing and the heat that helped speed the harvest in some places is now drying out vines in others.
To acclimate, old ways are increasingly being replaced by new ones, including using granular data aimed at tracking the progress and health of vines in a fast-warming environment. According to startups such as Ticinum Aerospace and TerraNIS, satellite technology is being used by vintners to harvest the right grapes at the right moment.
"Sometimes producers don’t collect data on grapes, or they do but it’s not stored in an easy way, or they don’t know which plots they collected samples from,” says Daniele De Vecchi, project manager at Ticinum Aerospace for Saturnalia, a data platform for evaluating vintner crops. "Now the wine industry can make decisions based on data. It’s not so romantic, but I think it’s the only way to move forward.”
Marc Tondriaux adds that more French growers are joining in. He is president and founder of TerraNIS, a company that provides agricultural data based on satellite and drone imagery. "Just ten years ago, the key customers for these applications were mostly in Bordeaux,” Tondriaux said. "But now we’re seeing it more in southern regions.”
But while this technology is being brought to bear for winemaking, soon it may serve a more critical role in helping agriculture adapt in general.
Better data, better decisions
After decades of progress, the number of people suffering from malnutrition has started to move in the wrong direction. Global warming, supply chain disruptions tied to extreme weather and even declines in nutrients due to additional atmospheric carbon dioxide are driving a global food crisis. These trends are particularly dire in areas most susceptible to crop killing heat, with many countries teetering on the brink of famine.
In ten climate hotspots from Guatemala to Afghanistan, acute hunger has more than doubled in six years, according to U.K. charity Oxfam. But cutting-edge satellite sensor technology could play a big role in slowing that down. Experts envision a future in which farmers can manage fields based on Earth observation data that is mostly free and focuses on crop disease, pest infestation, nutrient needs, water stress, ideal harvest time and quality evaluation.
Tondriaux says combining recommendations based on orbital or drone data with GPS-driven farm machinery could transform farming. In the process, it might just stave off the worst global warming has in store for farmers. And as a bonus, such technology has the potential to cut the agriculture sector’s greenhouse gas emissions by 13%, according to an April report by the World Economic Forum.
The report sees the market for satellite data in agriculture nearly doubling to almost $1 billion by 2030. It calculates the value of crop loss prevention by using satellites to detect pests and pathogens at $400 million, and envisions an almost 10% drop in water use by leveraging space-borne insights.
Satellite technology has long been used to help governments and futures markets make scale-level assessments, like the size of a coming harvest of corn in the U.S. or wheat in Ukraine. But newer technology has the capacity to help individual farmers measure and expand their own yield potential.
Satellites from NASA, the European Space Agency (ESA) and private companies such as San Francisco-based Planet provide ground images from a range of bands on the electromagnetic spectrum.
When sunlight hits the planet’s surface, certain wavelengths are reflected back based on the material the light hits and its condition. Chlorophyll, which plants use to make their food, absorbs much visible light, while a leaf’s cell structure reflects near-infrared wavelengths (NIR).
Sensors and cameras measure the intensity of the waves reflected back from Earth. High levels of reflected NIR light coupled with low reflectivity in the visible range indicates dense vegetation, such as forest or healthy crops. Little difference in reflectivity of the two spectral bands would point to sparse vegetation, such as desert or bare soil.
The nuances of these relationships have proven to be reliable indicators of levels of nitrogen, a key plant nutrient, as well as plant biomass, leaf area and chlorophyll content — which are all connected to soil water content too. These are quantified using the normalized difference vegetation index (NDVI), one of the satellite-based measurements most commonly used in agriculture. Scientists at TerraNIS and Purpan Engineering School, a research institute in Toulouse, France, have supported the data’s accuracy, showing a strong correlation between levels of nitrogen taken from leaf samples and analyses derived from satellite imagery.
With each pixel of an image representing an area as small as half a square meter, this satellite data can be overlaid on the map of a field, allowing fertilizer to be applied only where it is needed. A low NDVI as a crop approaches harvest time, for example, would indicate the need for nitrogen fertilizer. "We’ve been treating crop fields like all of that ground is exactly the same, when we know for sure this is not the case,” says Misty Tucker, industry principal for agriculture at Planet. "Satellite data helps us to micromanage our fields at a much more granular level.”
Seeing the light
If such technology became widely available, the resources saved, emissions avoided and crops preserved in the face of a shifting climate could have a significant impact on both the fight to slow global warming and protect food supply.
In this respect, policymakers are beginning to see the light. The European Union is changing its Common Agricultural Policy with satellite monitoring in mind to reduce greenhouse gas emissions, fertilizer use and oceanic dead zones. In the U.S., the Precision Agriculture Satellite Connectivity Act — passed by the House of Representatives in April — obliges the Federal Communications Commission to consider whether changes to satellite communications rules could help precision agriculture, and develop recommendations for Congress if so.
NASA’s suite of Earth observation instruments already helps "provide both global and local predictions of water availability, crop health and rates of production,” says Karen St. Germain, NASA’s director of Earth science, and its planned Surface Biology and Geology instrument may advance the ball even further. Meanwhile, ESA’s Sentinel satellites combine spatial and temporal resolution, along with a broad bandwidth that has proven particularly useful to those who provide satellite data to the agriculture industry.
"The crop is always changing,” says Sara Antognelli, research and development manager at Agricolus, an Italian satellite data company that says it can work with 140 crops, from grapes to grains. "So you have to be quick in detecting problems. Sentinel’s different bands to detect both soil moisture and vegetation health is very rare.”
The TerraNIS-Purpan study found Sentinel’s freely available data to be more accurate in assessing nitrogen status than even higher-resolution data from satellites that charge for access. And new instruments may bring even greater insights.
Satellites can’t do everything, of course. Findings often need to be confirmed on the ground, and overreliance on orbital data can lead to sloppiness, warns José Manuel Amigo, an expert in hyperspectral imaging and chemical analytics at the Basque Foundation for Science in Bilbao, Spain.
"Remote sensing is a wonderful discipline that helps farmers in many situations,” he says. Still, assumptions are too often baked in and limitations are dismissed. "Treating the data is not easy, and correlating parameters with actual issues” can be a leap too far. "Researchers forget that the answers they give to farmers must be followed by intensive validation and a sound chemical explanation.”
Still, Kaitlyn Gold, a professor of plant pathology at Cornell University in Geneva, New York, says she is excited about the potential to detect crop disease early enough to do something about it. "A changing climate will expand the suitable range for invasive pathogens,” she says, while heat and drought stress on a plant "will leave it far more vulnerable to opportunistic diseases.”
Satellites will enable "high-quality assessments of risk that allow for successful early intervention.”