The Economist: Harvest moon: Agriculture and satellites
Artificial satellites are helping farmers boost crop yields.
FOR farmers, working out the optimal amount of seed, fertiliser, pesticide and water to scatter on a field can make, or break, the subsequent harvest. Regular laboratory analyses of soil and plant samples from various parts of the field can help—but such expertise is costly, and often unavailable. A new and cheaper method of doing this analysis, though, is now on offer. Precise prescriptions for growing crops can be obtained quickly, and less expensively, by measuring electromagnetic radiation reflected from farmland. The data are collected by orbiting satellites.
The spectrum of this radiation—which can be in the form of either natural sunlight or artificial radar—can reveal, with surprising precision, the properties of the soil, the quantity of crop being grown, and the levels in those crops of chlorophyll, various minerals, moisture and other indicators of their quality. If recent and forecast weather data are added to the mix, detailed maps can be produced indicating exactly how, where and when crops should be grown. The service usually costs less than $15 per hectare for a handful of readings a year, and can increase yields by as much as 10%.
Such precision farming using satellite-based intelligence is in its infancy. ...
