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 better calls for on semi-arid zones for offering human susten ance and the chance that this can increase desertification is a grave drawback. 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 platforms during this quarter. huge fluctuations in ag ricultural construction have happened in semi-arid zones of Australia, North Ameri ca, and the Soviet Union as a result of periodic droughts, even supposing huge 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 reduced. Irrigation can be utilized to extend and stabilize agricultural construction in semi-arid zones as mentioned in quantity five of this sequence, Arid sector Irrigation. the current quantity, Agriculture in Semi-Arid Environments, makes a speciality of 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 really to be had for irrigation. This quantity is designed to help agricultural improvement in those components and contains experiences and analyses of obtainable info by way of scientists operating in Africa, Australia, and on the U ni versity of California.
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Extra info for Agriculture in Semi-Arid Environments
Ho, 1977). The best known Yang-Shao site is Pan-p'o, located in Shensi Province, since it represents the earliest stage of settled village communities with proven field agriculture, well-patterned graveyards, painted pottery, and animal domestication centered mostly on pigs (Ho, 1977). C. C. Excavations at Pan-p'o turned up bushels of husks of one of the Chinese millets, Setaria italica. Another millet grown by the Yang-Shao farmers was Panicum miliaceum. Remains of hazelnuts, chestnuts, and pine seeds are also found in Yang-Shao sites.
The chief crop is maize. Today wells are filled in at plowing time and reopened as needed, but before the Spanish Conquest, when draft animals were introduced, wells were undoubtedly permanent features of the farming system. As many as three crops are grown annually. Dry farming, although less reliable, is also possible in this zone of high alluvium where the water table rises to near the surface, and was undoubtedly practiced in Formative times. C. the high alluvium was intensively farmed, probably with a major reliance on pot irrigation.
Another type of depression farming (antiquity not discussed) originated on the semi-desert dry plains of southeastern Russia. 25 to 12 ha. Snow, rain, and melt water in the spring accumulate in these depressions, providing an extra 300-500 mm of moisture. Soil in these depressions contains no salts, has 4% to 5% humus, and a depth of 100-120 cm. C. or possibly earlier, were built along various rivers of the desert and steppes of Central Asia and the Caucasus. C. D. P. Tolstov (1948a, 1948b, 1958).