ISHS Acta Horticulturae 278: Symposium on Scheduling of Irrigation for Vegetable Crops under Field Condition
PROBLEMS AND PERSPECTIVES OF IRRIGATION |
| Author: | A. Alvino |
| Abstract:
After the report of J.E. Hansen, Director of the NASA Goddan Institute for Space Studies (1988), it is probable that the way people look at the environment has changed remarkably. All of us, researchers, politicians, administrators of public and private enterprises, recognize that man's activities over the past two decades are resulting in a large increase of the atmospheric levels of CO2 (U.S. National Research Council, 1983; Seidel and Keyes, 1983; Mintzer, 1988), which has changed from 315 μl l-1 in 1958 to 352 μl l-1 in 1988, reaching now the highest concentration of the last 160 000 years (Brown et al., 1989). CO2 and other 'greenhouse' gases are likely to have a major effect on climate with an impact not only on agriculture but also on the whole social and economic fabric of this planet. It is, however, only during the last year that the recognition of these problems has begun to reach public and practical consciousness in all countries. The reknowned news magazine TIME, for example, dedicated its front cover of the first issue of 1989 to our sick planet. It is essential that the irrigation experts make efforts, in the areas of their specialization, in order to unravel the undoubted complexity of the interactions between climate, crops and man's activity. It is necessary to consider the technical reports produced by institutions such as the World Meteorological Organization (World Climate Programme, 1988), the Worldwatch Institute (Brown, 1989), the World Commission on Environment and Development of the United Nations. They all agree on the bad state of the world, the seriousness of which goes beyond geographic boundaries, and which, to quote the report of the World Commission on Environment and Development (1987), will make up "Our Common Future". There are major uncertainties about the details of the model projections in these different reports (figure 1): the range between the maximum top and minimum bottom predictions of the different models is more than 8°C over much of the arctic region and more than 2°C over much of the earth's surface. Even though the increment of the earth temperature is not a direct menace to the world life at present, it seems convincing that the phenomenon is worrying, because the 5 warmest years of this century are in the | |
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