Fulu 



tion of domestic land, water, mineral, and energy re- 

 sources and rising domestic food prices. Therefore, in the 

 long term, U.S. interests may be best served by increasing 

 the worldwide distribution of food production activities, 

 as well as by increasing the total productivity of world 

 agriculture (AAAS-8; lA). 



The agricultural enterprise, like many other areas of 

 American life, is currently facing some significant prob- 

 lems, and the appropriate development and application of 

 science and technology capabilities to those problems will 

 be crucial. The most critical problems may be in agri- 

 cultural productivity. While the productivity of agricul- 

 ture has been increasing both in the United States and in 

 other countries at a very high rate for the last half century, 

 the rate of increase has recently begun to slow, suggesting 

 that productivity increases could reach a plateau 

 (AAAS-8; Outlook I). At the same time, population pres- 

 sures, among other factors, will continue to place ever- 

 increasing demands on worldwide food supplies (NRC-1; 

 AAAS-8; AAAS-9). 



To some analysts, the slowing rate of agricultural 

 productivity growth suggests that current Western 

 agricultural approaches, involving energy-intensive but 

 labor-saving technologies, may be reaching the point of 

 diminishing returns, and new approaches to agricultural 

 endeavors need to be contemplated (AAAS-8). Con- 

 tinued attention to the development and implementation of 

 a wide variety of new technologies, coupled with consid- 

 eration of the social and economic aspects of the agri- 

 cultural enterprise, will be needed over the next 5 years to 

 permit the continued growth of American agricultural 

 productivity. What follows are discussions of three as- 

 pects of the agricultural enterprise that contain special 

 opportunities for science and technology to facilitate agri- 

 cultural productivity growth. They concern (1) the input 

 resources needed to support agriculture, (2) potential 

 changes in crop yields, and (3) postharvest treatments. 

 The final part of this section emphasizes interactions 

 between the agricultural enterprise and other sectors of 

 society. 



Before discussing the opportunities and needs for sci- 

 entific and technological development, it should be men- 

 tioned that changes in agricultural approaches always 

 involve tradeoffs, or various ways of combining input and 

 output factors. As in the breeding of plants and animals, 

 where an increase in one characteristic, such as hardiness, 

 typically is compensated for by decreases in another 

 characteristic, such as yield, so the practice of agriculture 

 trades off labor demands against demands for other re- 

 sources, such as energy, water, fertilizers, and pesticides. 

 The tradeoffs may be in physical terms, such as limits on 

 real resources, or they may be in economic terms, such as 

 price differentials. Thus, for example, water may be abso- 

 lutely unavailable in some circumstances, but in other 

 cases it may only be very costly. In many cases, it is not 



riomil Area Problems. Opportunilit'S, and Constraints 73 

 absolute limits but economic factors that constrain agri- 

 cultural production (AAAS-8). Productivity is defined as 

 "output per land unit, per time unit, per cost unit,"" and it 

 can be influenced significantly by technological practices 

 that affect any one or all of those components. 



ENSURING ADEQUATE RESOURCES FOR THE 

 AGRICULTURAL ENTERPRISE 



One important set of problems and opportunities concerns 

 the inputs to or resources for the agricultural (i.e., grow- 

 ing) process. Although there is a wide variety of inputs to 

 agriculture, three are directly related to science and tech- 

 nology. They are land resources, water resources, and the 

 supply of nutrients needed to sustain plant growth. 



CONSTRAINTS ON THE AVAILABILITY OF LAND 



The most basic of all resources for the agricultural enter- 

 prise is land, and unless there are some truly revolutionary 

 changes in development policies and agricultural ap- 

 proaches, land availability will be a major limiting factor 

 on agricultural productivity for decades. As land becomes 

 increasingly valuable for other purposes, agricultural ac- 

 tivities tend to be pushed toward less productive land. 

 That phenomenon is most striking in the industrialized 

 countries, but it is also beginning to be felt with increasing 

 severity in the third world (lA). Thus, the use of less than 

 prime land for farming and ranching in turn requires 

 increased use of other resources, including water, fertil- 

 izer, and, particularly, labor, raising the costs of the proc- 

 ess and lowering the return even further In addition, the 

 use of poor land for agriculture puts a high strain on that 

 land, leading to very rapid soil degeneration and erosion. 

 Cropping practices that rely on heavy use of monoculture, 

 chemicals, and heavy machinery reduce the fertility and 

 tilth of the soil even further One way to counteract de- 

 creased adequacy of the soil is through a variety of soil 

 conservation practices. However, the techniques of soil 

 conservation, while generally understood, are still not 

 practiced extensively even in the United States (AGR). 

 Encourging soil conservation is one approach through 

 which prompt policy attention might be highly effective 

 over the next few years. Other issues concerned with land 

 resources, particularly the problems associated with de- 

 forestation, are discussed in the Natural Resources section 

 of this chapter 



THE PROBLEM OF WATER RESOURCES 



The availability of water may prove to be an even more 

 severe limiting factor in the development-of agriculture in 

 coming years (AAAS-8). In the United States, 80-85 

 percent of total fresh water use is for agriculture (by 



