Commentary  The conversationalist: Environmental agriculture from an altitude of 12,000 m

It makes sense for those without exceptionally long legs, small bladders, or aerial restlessness to want the window seat. This may be especially true for long flights, during which the view provides plenty of nourishment to the wandering mind.

Raja Sengupta, an assistant professor in Geography and the McGill School of Environment, and an associate member of the McGill School of Computer Science, agrees. “Most of us like to look out of airplane windows. I like to see the patterns that people have left on the earth; those that one sees from an airplane, or those we can see in the points and lines and polygons of GIS [Geographic Information Systems] programs.” Unlike Sengupta, I’m often inclined to separate these images from terrestrial reality, but he showed me that by grounding the aerial perspective in fact, we can discover information about the agriculture, environment, and historical or social facts about the local culture.

What exactly is the aerial view over rural Quebec, south and east from here, toward the St. Lawrence River? You should see a line of white piano keys sitting still beside the river, that have, from moisture and disuse, grown over green with mould, moss, and algae of different shades. Perhaps a familiar story, Sengupta explains how these patterns reveal the socioeconomic history of the area. In the earth 17th century, the only means of trade and transportation for the riverside colonies was by the St. Lawrence and its tributaries. Access to the river was, therefore, in high demand. In an attempt to evenly distribute these plots of land to their heirs, the noblemen would divide them into long thin strips each with one side touching the waterway.

Flying further east – far east – you look out over Bali to see what looks like the microscopic view of some reptilian skin. Irregular slabs of dermis overlap unevenly, sharp on the edges, and with some strange encrusted growth on its underside. In reality, there is nothing mysterious about what’s growing underneath these ridges; it’s rice. These patterns are what Sengupta, in his agriculture-speak, calls “terraces.” This farming technique allows cultivation of hilly areas, conserving soil by preventing the surface runoff that occurs during irrigation: a good idea that dates back to the Incas in the Andes.

Looking over Great Plains or the Canadian prairies as you travel back home, you’ll see something that may seem like a taxonomic exploration of the green-eyed iris. Irises of many subjects, separated from the pupil and sclera, are lined up side-by-side across the landscape, some cut in half for closer observation, some more brown than bright. According to Sengupta, these patterns appear because of the specific irrigation systems in which sprinklers rotate around a central point.

Centre Pivot Irrigation Systems are used almost exclusively in the prairies since it is one of the few irrigation techniques that can accommodate the flat, yet undulating terrain. The circular plots waste land, leaving small unused triangles between each circle, but that’s because availability of water – not land – is the limiting factor in the prairies.

“You can use maps for anything as far as the imagination allows,” Sengupta says. Perhaps in considering crop patterns and land holdings in such a way, I took his words too far. It seems to me, however, that the real explanation is at times more interesting than the imagined.

Rosie can be reached at when she’s not flying everywhere.