From “Earthweek – A Diary of the Planet: Weekly News” that is featured on our web site at as part of “Earth Gate” which includes a weekly environmental news map and short descriptions of major events occurring around the world:
From space, Noreen Thomas’ Organic Farm in northwest Minnesota, adjacent to the North Dakota border, looks like a patchwork quilt. Fields change hue with the season and with the alternating plots of organic wheat, soybeans, corn, alfalfa, flax, or hay.
Noreen enjoys this view from hundreds of miles above Earth’s surface — not just for the beauty, but for how it helps them be more effective and environmentally friendly farmers. She is among a growing group of Midwest farmers who rely on satellite imagery from Landsat to maximize their harvest and minimize damage to their fields. It’s become another crucial tool just like their tractors and sprinklers.
The top true-color image, taken by the Landsat satellite on September 10, 2009, shows Thomas’ organic farm along the banks of the Buffalo River. Lush green fields dominate the image, though some crops have already been harvested, leaving squares of tan and brown. The lower image shows the same scene in false color. Made with infrared light, the false-color image provides a wealth of information about crop conditions.
To the untrained eye, the false-color images appear a hodge-podge of colors without any apparent purpose. But the Thomases are now trained to see yellows where crops are infested, shades of red indicating crop health, black where flooding occurs, and brown where unwanted pesticides land on her chemical-free crops.
The images help Noreen root out problems caused by Canadian thistle and other weeds. They help confirm that her crops are growing at least 10 feet from the borders of a neighboring farm — required to maintain organic certification. They can also spot the telltale signs of bottlenecking in the fields — where flooding is oversaturating crops — and monitor the impact of hail storms. “We’d have to walk our entire 1,200 hundred-plus acres on a regular basis to see the same things we can see by just downloading satellite images,” said Noreen, who recently began providing the farm’s coordinates to her buyers in Japan. “There’s no more ideal way I know to show how healthy our crops are to someone thousands of miles away.” Full story: NASA
