Fertilizers for food production vs energy needs and environmental quality.

The world is experiencing an energy crisis that is restrictive to agricultural requisites production at the same time that food is becoming increasingly short on a global basis. Fertilizers are the most energy demanding of these inputs and have become very expensive and intermittently short in supply with the reduced availability of fossil fuels. They have been indicted, furthermore, as environmental pollutants due to their presumed role in eutrophication and in being a source of excessive NO3-N that may accumulate in some leaf crops and in drinking waters. Exponential growth in fossil fuel consumption cannot continue. Economies can be made in the agricultural sector, which does indeed consume substantial quantities of energy. The energy consumed in this very essential food-producing process, however, is almost insignificant compared with that involved in transport and processing of food beyond the farm and with other energy expenditures in modern society. A shift in priorities will certainly be required in adapting to the real world of the 1970s if man's first need is to be met. Economies in fertilizer use can be made by adherence to known agronomic principles. Savings in fossil fuel energy can probably be effected also in the production of N fertilizer, by far the most fossil-energy-demanding process in the realm of agriculture. Considerable research remains to be done, however, under varied climatic conditions for understanding and controlling processes by which residuals from fertilizers may become environmental pollutants. The various issues in this paper must be resolved promptly in consideration of the now-existing energy crisis and the imminent world food crisis.