Irrigation is the application of controlled amounts of water to plants at needed intervals. Irrigation helps to grow agricultural crops, maintain landscapes, and revegetate disturbed soils in dry areas and during periods of less than average rainfall. Irrigation also has other uses in crop production, including frost protection, suppressing weed growth in grain fields and preventing soil consolidation. In contrast, agriculture that relies only on direct rainfall is referred to as rain-fed or dry land farming. Irrigation systems are also used for cooling livestock, dust suppression, disposal of sewage, and in mining.
Caral is a large archaeological site in the Supe Valley of Peru, about 120 miles north of Lima.
Caral has been found to be the oldest urban center of the Americas, belonging to the Norte Chico civilization. The area displays a lot of elements that were going to be perfected later by other Andean civilizations, such as <em>quipu</em> (a knotted, textile piece used for record keeping). The quipu is known because of the Inca, who perfected it. The evidence in Caral means this system of recording is much older than scientists had originally thought.
Caral was a thriving urban center at roughly the same time the pyramids of Egypt were being built, and it seems to have been well-known in antiquity. This implies that civilizations in South America might be much older that archaeologists thought, and achieved great accomplishments at a much earlier date than previously assumed. It appears to have been the model for the urban design of all major Andean cities of the next four millenia. Because of its level of preservation, its size, its influence and its age, it is very likely that Caral will provide us with the answers to a lot of questions regarding the origins of the Andean civilizations.
You have to walk through heat, snow,rain,
D. The end of the cold war
