A/42/427
English
Page 137
Intensive agriculture may quickly exhaust the soil cover, causing its degradation, unless some special soil protection measures aimed at constant restoration and expanded reproduction of fertility are taken. The task of agriculture is thus not confined to obtaining the biological product but extends to constant maintenance and augmentation of soil fertility. Otherwise we will very quickly consume what by right belongs to our children, grandchildren, and great-grandchildren, to say nothing of more distant descendants. It is this misgiving – that our generation lives to a certain extent at the expense of the coming generations, thoughtlessly drawing on the basic reserves of soil fertility accumulated in the millennia of the biospheric development, instead of living off the current annual increment – that causes the increasing concern of scientists dealing with the state of the planetary soil cover.
B. G. Rozanov
Moscow State University
WCED Public Hearing
Moscow, 11 Dec 1986
3.2 Water Management
63. Improvements in water management are essential to raise agricultural productivity and to reduce land degradation and water pollution. Critical issues concern the design of irrigation projects and the efficiency of water use.
64. Where water is scarce, an irrigation project should maximize productivity per unit of water; where water is plentiful. it must maximize productivity per unit of land. But local conditions will dictate how much water can be used without damaging the soil. Salinization, alkalization, and waterlogging can be avoided by a more careful approach to drainage, maintenance, cropping patterns, the regulation of water quantities, and more rational water charges. Many of these objectives will be easier to realize in small-scale irrigation projects. But whether small or large, the projects must be designed with the abilities and aims of the participating farmers in mind, and then involve them in the management.
65. In some areas excessive use of ground-water is rapidly lowering the water table - usually a case where private benefits are being realized at society's expense. Where ground-water use exceeds the recharge capacity of local aquifers, regulatory or fiscal controls become essential. The combined use of ground and surface water can improve the timing of water availability and stretch limited supplies.
3.3 Alternatives to Chemicals
66. Many countries can and should increase yields by greater use of chemical fertilizers and pesticides, particularly in the developing world. But countries can also improve yields by
