Between the tomato plants growing in sun-drenched fields in southern Italy, the walnut or ceiba leaves in Brazil, and satellites orbiting high above, a subtle messenger travels. Light in wavelengths invisible to the human eye carries valuable information about the health of vegetation. For several years now, humans have learned to capture and analyze this light, giving rise to precision agriculture.
“It means monitoring an agricultural area,” explains Roberta Bruno, Technical Manager for Agrigeo at e-GEOS. “Satellites allow us to analyze specific characteristics such as water stress or vegetation conditions, even in the presence of pathogenic attacks.”
Water stress refers to a lack or excess of water, or indices that may indicate the presence of pests. Once transferred onto a map of the cultivated area,“these data can support farmers’ decisions for example, where and how much to irrigate, or how to use fertilizers. In the face of significant climate change, with increasingly scarce water resources, we need to optimize their use and support farmers,” adds Bruno.
Where the field suffers
The experts at e-GEOS mainly rely on the electronic eye of Sentinel-2, the European Earth observation constellation. Using multispectral optical data, both visible and non-visible light, they monitor the health of plants and their distribution within a field based on vegetative stress.
“Essentially, we classify the image pixels and analyze how much they deviate from the field’s average trend,” explains Flaminia Spasiano, satellite data analyst at e-GEOS. “If the deviation is negative, we’re seeing vegetative stress - possibly caused by flooding, drought, or even a buried pipe running under that portion of the field. If an area shows a consistent anomaly over time, we can investigate further at higher resolution, perhaps with a drone flight.”
The collected data are transformed into applications and services for farmers, who can understand the condition of their crops and act precisely where needed as well as for institutions.
“Every year Europe allocates funds to support farmers’ income and promote sustainable practices,” says Bruno. “At e-GEOS, we manage the monitoring that ensures EU funds are properly distributed. Satellite observation helps verify whether agricultural practices match what’s declared.”
These tools are also valuable for governments and insurance companies, which can provide compensation in regions hit by natural disasters - such as floods, extreme droughts, or pathogen outbreaks - all exacerbated by climate change.
Watching over forests
It’s not only about precision agriculture. Multispectral technology is also crucial for monitoring all types of vegetation from urban greenery like parks and gardens to the world’s forests, now more vital than ever in mitigating global warming and atmospheric CO₂ levels. Yet they’re under threat from droughts, fires fueled by high temperatures and lack of rain, and human activity.
“Thanks to multispectral sensors, we can detect whether a forest is under pathogen attack, has been destroyed by fire or storms, or is being affected by deforestation,” adds Roberta Bruno.
Feeding the world in the age of climate crisis
The wide reach and precision of satellites make them powerful tools - capable of covering vast and remote areas, often inaccessible by land, such as those in developing countries. These are places where the climate crisis hits the most vulnerable populations hardest. "By comparing today’s satellite imagery with the long historical series we have, we’re noticing that areas once fertile and cultivated are now largely abandoned, showing a clear trend toward desertification,” concludes Bruno. “By 2040, the global population is expected to reach around 9 billion. It’s therefore increasingly crucial to ensure that food remains available for most of humanity. Satellites can play a key role in monitoring the impact of climate change on agricultural yields.”