Variety is the spice of life, and in this picture we see a variety of agricultural practices around the world from space. The way agriculture is done depends on topography, soil type, crop type, annual rainfall and tradition. In this montage, these differences are graphically illustrated by the variation in field geometry and size.
In Minnesota (upper left) the very regular grid pattern reflects early 19th century surveying; the size of the fields is a function of mechanization, which dictates a certain efficiency. In Kansas (upper middle), center pivot irrigation is responsible for the field pattern. In northwest Germany (upper right), the small size and random pattern of fields is a leftover from the Middle Ages. Near Santa Cruz, Bolivia (lower left), the pie or radial patterned fields are part of a settlement scheme; at the center of each unit is a small community. Outside Bangkok, Thailand (lower middle), rice paddies, which are fed by an extensive network of canals that is hundreds of years old, appear as small skinny rectangular fields. And in the Cerrado in southern Brazil (lower right), the cheap cost of land and its flatness have resulted in enormous farms and large field sizes.
The images were taken by NASA's Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER). Each sub-image covers an area of 10.5 x 12 kilometers.