This situation has developed in West Pakistan where extensive 

 irrigation has been used. Chemical fertilizers produce various hazards, 

 such as the pollution of drinking water and the eutrophication of 

 bodies of fresh water. The chemical control of insects and weeds, 

 through the use of DDT and other chlorinated hydrocarbons, 

 threatens many species of animal life. 



Such costs and impacts as these may inhibit the spread of the 

 "green revolution" — the application of high yield seed strains and 

 modern technologies. This prospect arises from the fact that the new 

 strains have high yields largely because they respond well to fertilizer, 

 irrigation water, and pesticides. 



Scientific research may yield means for overcoming several of 

 these problems and side effects. Research in genetics may lead to plant 

 strains that grow well in saline soils. Better understanding of nitrogen 

 fixation could provide the basis for enhancing natural fixation 

 processes and thereby lessen the dependence on chemical fertilizers. 

 Similarly, new approaches to controlling pests — such as rapidly 

 degradable pesticides or biological control, as exemplified by the mass 

 sterilization of screwworm flies — can reduce significantly the need for 

 the older forms of chemical control. Beyond this, research may provide 

 means for enhancing agricultural productivity in several ways, 

 ranging from methods of accelerating the photosynthesis process to 

 the growth of plants in a liquid nutrient rather than in soil. 



Whether the world food situation improves or worsens in the 

 years ahead depends upon many factors such as: population growth, 

 global climate, demand for animal protein, availability and cost of 

 agricultural inputs, economic incentives for food production, and 

 advances in science and technology. Since the future course of these 

 factors cannot be foreseen, it is not known if the world faces a chronic 

 food supply problem or a state of temporary shortages which will ease 

 in the coming years. Population growth at current rates, however, will 

 continue to exert immense pressures on the food production capability 

 of the world. 



In developing his agricultural system, man has selected a few 

 plants with which he has achieved high productivity through 

 extensive cultivation. This has led to a high degree of dependence on 

 "monocultures" as the prime source of food. The long-term instability 

 of intensive monoculture as practiced in the United States and 

 elsewhere has become evident in the increased susceptibility to insect 

 pests and pathogens. Cotton culture had to be abandoned in several 

 areas of this continent because insects feeding on the plant developed 

 resistance to all pesticides. The vulnerability of certain high-yield 

 strains of plants used in monoculture was demonstrated in the 

 summer of 1970 by the billion dollar loss of corn to blight, which 

 occurred in large areas of the United States. Intensive monocultures, 

 furthermore, are vulnerable to small climatic changes and heavily 



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