By Anthony E. Hall
The semi-arid zones of the area are fragile ecosystems that are being sub stantially changed through the actions of mankind. expanding human populations have ended in larger calls for on semi-arid zones for supplying human susten ance and the prospect that this can improve desertification is a grave predicament. those zones are harsh habitats for people. The famines that resulted from drought in the course of the overdue 1960's and the 1970's within the African Sahel illustrated the unreliability of current agricultural structures during this sector. huge fluctuations in ag ricultural construction have happened in semi-arid zones of Australia, North Ameri ca, and the Soviet Union because of periodic droughts, even if significant ag ricultural expertise has been dedicated to agricultural improvement in those zones. The problem to mankind is to control those various semi-arid zones in order that professional ductivity is elevated and stabilized, and environmental deterioration is diminished. Irrigation can be utilized to extend and stabilize agricultural creation in semi-arid zones as mentioned in quantity five of this sequence, Arid region Irrigation. the current quantity, Agriculture in Semi-Arid Environments, specializes in dryland farming in semi-arid zones, and is suitable to the big components of the area the place rainfall is restricting and the place water isn't on hand for irrigation. This quantity is designed to aid agricultural improvement in those parts and involves reports and analyses of obtainable details by way of scientists operating in Africa, Australia, and on the U ni versity of California.
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Additional info for Agriculture in Semi-Arid Environments
One canal system referred to as the Xiquila aqueduct is 6 km long and traverses very steep and rocky terrain covered today with cacti and thorny shrubs. The canal apparently took water from the Rio Xiquila in much the same manner as water is diverted today, with low diversion dams or weirs of rocks and brush. The canal is supported along much of its course by a dry-laid masonry retaining wall. It is believed to have supplied irrigation water for several villages along its route. Another canal system in the same vicinity is less extensive.
Seeds found in burials indicate that wheat, barley, millet, and rye were cultivated in a large area stretching from the Lower Danube to the middle reaches of the Dnieper River. In western parts of the Black Sea regions and farther eastward, in the Don and Volga steppes, cultivation appears to have often been limited to droughtresistant crops such as millet. C. (Kovda, 1961). This innovation opened areas of the steppes where the toughness of the sod had been impenetrable to wooden hoes and led to fieldcrop farming on an extensive scale.
Had they not mastered this Ancient Agricultural Systems in Dry Regions 31 problem, it is doubtful that the village could have survived for a millennium and a half. There is no reason to believe that any central hydraulic authority was needed to construct and maintain the canals at Snaketown. Where several villages cooperated and depended on the same canal, however, some form of intervillage management authority must have existed (Haury, 1976). Bohrer's (1970) study of the plant remains from Snaketown reveals that a number of noncultivated species were important food items throughout the period of occupation.
Agriculture in Semi-Arid Environments by Anthony E. Hall