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SECTION II: NATURAL RESOURCES BASE INPUT MANAGEMENT, AND THE ENVIRONMENT INTRODUCTION The immediate challenge for this nationâand indeed the worldâis to optimize agricultural and other renewable re- source productivity per unit of land area; per increment of water; per unit of energy, pesticide, and fertilizer input; and per unit of time. Not only is agriculture heavily dependent on climate and short-term variations in weather patterns, but the ability to produce more food is sharply influenced by natural resources of soil and water, and input management of energy, pesticides, and fertilizers. The management of these resources and inputs will have a major effect not only on food production but also on the quality of the environment. Some estimates indicate that twice as much land may be physically available upon this earth for crop production than the 1.5 billion hectares currently used (Univ. of Cal. Task Force 1974). In addition, there are about 3.6 billion hectares of potential grazing land. Bringing new land into production requires expenditures of resources and labor, and some of the potentially arable land will be expensive to bring into production. We must carry out research on soil inventories, soil fertility tests, conservation of soil and water resources, and cropping systems if we intend to increase agricultural production with minimal damage to the environment. It is essential that we have an inventory of our soil resources so that we know how many hectares we have of land with high, medium, or low potential for producing crop and forage plants. This inventory is needed to provide the basic data for all future food and fiber production programs. Besides land, water is another critical natural re- source. Where it can be developed, irrigation offers a major opportunity to increase production. Of the 344 million hectares in the world that could be irrigated, only 200 million are currently irrigated (Univ. of Cal. Task Force 1974). In the U.S., 15 million hectares of land are irrigated. Areas of research concerned with use of the water resource for increased agricultural production include harvesting, reuse of water, water management, and water conservation practices. Next to land and water, the basic and perhaps most fundamental determinant of agricultural production is the influence of weather and climate. The most efficient use of -65-
the weather and climate resource through weather data and forecasts and weather modification techniques should be a major goal of the agricultural sciences. Since agriculture in its most productive form in the developed nations depends upon large quantities of energy, a major challenge is to reduce energy inputs into food produc- tion systems without jeopardizing productivity or energy output. Research areas include the quantification of energy requirements in the food and fiber system, low-energy substitutes for high-energy fertilizer, and conservation of energy on the farm, primarily from alternative crop production techniques. Fertilizers have been a major factor in increasing yields over the past few years. Recent fertilizer shortages have intensified difficulties of expanding crop production, especially in developing countries. Another major factor in increasing yields is the wide variety of chemicals that has been used to protect plants and animals. The development of new nonpolluting chemicals which can be applied efficiently and in concert with biological and management control programs is of major importance for the protection of crops and livestock. Even though there are great differences among nations in available resources, the basic technological data exist with which to make more effective use of resources to increase agricultural productivity. To do this, however, will require a thorough analysis and synthesis of what is already known about a specific natural resource and its management. Such state-of-the-art (or state-of-the-science) studies will need to be carefully planned and coordinated, and they should be supported with adequate funds and administrative commitment to insure their successful completion and implementation. Such studies should identify critical gaps in knowledge and point out research needs; they should also provide the knowledge basic to putting new or old agricultural management techniques into practice. -66-
CHAPTER 7 LAND RESOURCE RECOMMENDATIONS 1: Soil Resources Inventory. The soil resource inventory should be completed and should include laboratory characterization of key soil properties. 2: Interpretation and Use of Soil Resource Data. Studies should be undertaken on land suitability for differing types of agricultural production, irrigation potential, and fertilization needs, including forage management. 3: Soil Fertility Evaluation. Studies should be made of soil fertility and fertilizer needs for major crops on main soil types. 4: Conservation of Soil Resources. Research should be intensified on erosion control measures. 5: Farming Low Precipitation Areas for Maximum Production. Existing information on dryland farming systems should be mobilized, and research should be directed toward developing food crops and land management practices on lands where availability of water is the limiting factor. 6: Use and Management of Rangelands. A rangeland resource inventory should be made with sufficient detail to determine the potential carrying capacity of the different soils and to permit development of management strategies. SOIL RESOURCES INVENTORY Rationale Estimates regarding the availability of land for future food production have been made by various scientists based on limited sources of data. To improve these basic data there is need for a systematic soil resource inventory to provide more specific information on the location and extent of the major kinds of soil and their potential to produce -67-
food and fiber. Such data must be supplemented by analyses of costs, markets, prices, and farm incomes. With such data and analyses, more accurate predictions can be made regarding the productive capacity of the different land areas of the U.S. to produce food and fiber. Interpretations based on the interaction of soil properties, soil slope, and climate provide the basic data needed in determining plant suitability, potential plant yields under alternative management systems, and the kinds of soil problems that limit yields. These data and analyses are essential for making realistic policy judgments regarding different ways of achieving needed production. They are also needed in locating those areas having the greatest potential for plant production and in determining priorities for development. Modern soil surveys are available for about one-half of the U.S. There is need to synthesize all available data and to prepare basic soil maps of priority areas as a basis for developing programs for food and fiber production. Implementation A U.S. soil resource inventory should be complemented with soil maps and reports, and laboratory characterization of key soil properties. High priority areas should be updated where information is now obsolete. Technology is known and available to carry out this task. The soil resource inventory can be implemented in a relatively short time through the employment of additional soil scientists and the use of remote sensing devices, computers, and other modern techniques. The USDA in cooperation with universities has the ability to do this work in the U.S. INTERPRETATION AND USE OF SOIL RESOURCE DATA Rationale With a soil resource inventory, which would include soil maps, soil descriptions, and selected laboratory data, predictions could be made for best land use including various kinds of crops. By recording in an orderly manner types of soil, and yields and responses to management practices, it is possible to identify areas having high, moderate, and low potential for producing food and forage. These are some of the basic data needed for determining priorities for land development and application of specific soil and water management practices including drainage, irrigation, and range and pasture improvement. An assessment can then be made regarding fertilizer, irrigation and drainage needs, and cropping systems best suited for -68-
various levels of management. Information will be needed on laboratory analyses (chemical, physical, and mineralogical) of selected samples from benchmark soils and on field measurements to determine irrigation and drainage potential. We also need initial plot trials and field evaluations of fertilizer response by selected crops accompanied by greenhouse studies of nutrient deficiencies' response. These activities are given high priority because of the their potential for most efficiently increasing productivity. Pre-development characterization of presently untilled lands should optimally require 2 to 10 percent of the total cost of bringing the land into crop production. Avoiding irrigation or drainage project failure and achieving high response from applied fertilizers and proper plant selection often result in avoided losses or increased returns several hundred times the cost of the research and development activities. Implementation Analysis and interpretation of existing soil maps and related resource data should be made to determine the suitability of land to types of farm, pasture, and range crops, irrigation and drainage potential, and fertilization needs. This analysis should include potential utility, pro- ductivity, economic and energy costs, and environmental impacts of bringing into production lands not now cultivated but classed as potential croplands. Irrigation needs, potential water resources, and energy costs of potential irrigation and drainage projects should be considered along with soil fertility-capability interpretations based on soil properties and projections of potential responsiveness to soil and water management practices, including added plant nutrients and lime. Attention should be given to lands now being farmed as well as to new lands. Soil maps and appropriate resource data also should be interpreted to show the potential for forage production under different levels of management, including reseeding, fertilization, brush control, and improved livestock management. In the U.S., soil maps should be interpreted to identify locations with greatest potential for agricultural production; and means (such as agricultural zoning) should be devised for retaining this land for agriculture. In the U.S., land resource data are now available in various forms. These data should be related to current land use and yields to determine the potential capacity of the U.S. to produce food and fibers. -69-
SOIL FERTILITY EVALUATION Rationale More efficient and environmentally sound use of fertilizer is needed in view of fertilizer costs, energy requirements for its production, and potential "leakage" of nitrates from fertilized fields. Strict fertilizer needs should be determined for currently cropped lands and for lands earmarked for new crop production. Soil fertility evaluation systems, employing the development of uniform methods for the same kinds of soils and calibrated by field plot and greenhouse experiments, determine optimum plant nutrient requirements and fertilization procedures. Implementation Soil fertility evaluation should be made that includes an R&D program for reevaluation of soil tests for assessing plant nutrient needs ("soil testing") for major crops on principal soils so that fertilizers may be used more economically and with less environmental impact (especially through reduction of excessive use of nitrogen). CONSERVATION OF SOIL RESOURCES Rationale As increased emphasis is placed on increased crop production to meet food needs, present cropland is likely to be cultivated more intensively, and new lands brought into crop production will frequently be more susceptible to water and wind/erosion than present cropland. As new lands are brought into production in the tropics, in moderate to high rainfall areas, soil erosion may be of increasing concern because of farmers' lack of knowledge about appropriate technology for erosion control. Implementation Soil conservation research in the U.S. should include refinements in wind and water erosion control measures to reduce sedimentation and to protect lands brought under cultivation with increased emphasis on crop production. Environmental protection considerations should include accelerated research in the U.S. on watershed modeling to protect water resources through control of nonpoint pollution from agricultural chemicals. -70-
FARMING LOW PRECIPITATION AREAS FOR MAXIMUM PRODUCTION Rationale Insufficient rainfall on much of the cropland limits production. A major portion of such land cannot be irrigated because of inadequate water supplies, economic considerations, or other reasons. These soils present unique problems of management for sustained production. These soils are fragile and subject to wind and water erosion; and economic margins are small. Technological developments for application in rainfed agriculture in semi- arid areas are behind technology for production in more humid climates. Although these semi-arid areas presently support relatively sparse populations, population pressure may increase, and the productivity must be maintained and increased where possible. It is essential that increased effort be directed toward application of existing knowledge as well as development of new techniques and innovations in dry-land farming. Implementation Existing knowledge should be collected, synthesized, and mobilized to help increase food production in semi-arid areas. This should be a team effort of producers, research and extension workers, and government agencies backed by specific funds and administrative support. A major research effort should be directed toward developing adapted food crops and land management practices to improve and sustain production on land where water is the limiting factor and where irrigation is not possible. These studies should be conducted by teams of scientists representing many disciplines and designed to develop systems of land and crop management that will optimize food production from the land resource. USE AND MANAGEMENT OF RANGELANDS Rationale Soil and climatic conditions in many areas of the U.S. dictate that much of the land be used for growing forage plants without cultivation. The area of nonarable but potential grazing lands is greater than the potentially arable land, because of restrictions imposed by topography, climate, or soil characteristics. The rangelands are both publicly and privately owned. The forage produced on these lands, most of which is harvested by grazing animals, constitutes an important part of the feed base for ruminant animals. -71-
Rangelands are usually so fragile that mismanagement can quickly result in permanent damage to the resource and its productivity. A decrease in forage production on rangelands will decrease ruminant animal production or increase the need for feed grains for animal feed. Use of rangelands is sometimes restricted, because some range forages are deficient in minerals required by grazing animals and, in a few cases, levels of elements, such as selenium and molybdenum, may be so high as to be toxic to animals. Management methods should be developed to prevent problems caused by these and other deterrents to full use of range resources. Implementation Rangeland resource inventories and management strategies for rangelands are essential for use and maintenance of rangelands. The inventory should include all important physical features of the areas including the characteristics of the vegetation, and in sufficient detail for the determination of the potential carrying capacity of the different soils and for developing management strategies. Management plans should be made and implemented on public and private range lands to maintain the productivity of forage for grazing animals. SELECTED REFERENCES Frey, H.T. (1972) Major Uses of Land in the United States: Survey for 1969. Agr. Econ. Rpt. No. 247. ERS, USDA, Washington, D.C. Barlowe, R. (1973) Agricultural Land Use Trends in the United States. Working paper prepared for the Organization for European Cooperation and Development, December. Resources Development Occasional Paper 74-1. Michigan State University. Heady, E.O. and J.F. Timmons (1975) U.S. Land Needs for Meeting Food and Fiber Needs. J Soil and Water Conservation, 30 (1): 15-22. University of California Task Force (1974) A Hungry World: The Challenge to Agriculture. University of California, July. U.S. Department of Agriculture (1974) Our Land and Water Resources: Current And Prospective Supplies and Uses. ERS Misc. Pub. No. 1290. -72-
CHAPTER 8 WATER RESOURCE RECOMMENDATIONS 1: Cropping Systems. Emphasis should be given to research on cropping systems to optimize productivity with regard to water use. 2: Soil Water Management Systems. On-farm water management technology and systems should be devised that maintain optimal soil moisture in relation to other environmental factors for crops in all climatic zones. 3: Water Use in Non-Optimal Cropping Systems. The effectiveness of use of water in systems that are non- optimal for crop production should be improved. 4: Technology and Management for Water Supplies. Technology and management practices to increase and conserve water supplies for agricultural production should be devised. 5: Constraints on Water Management. Laws and regulations for management of water resources for agricultural production should be reviewed. INTRODUCTION - Water is a basic renewable but limited resource. For the world as a whole it is a limiting factor in food production on more than 1.4 billion hectares of nonirrigated agricultural land and the major resource input that sustains production on approximately 0.16 billion hectares of irrigated cropland. Photosynthesis and transpiration are closely linked processes in the green plant-food production system. For a given crop, productivity varies directly with transpiration, other things being equal. The U.S. water resource faces not only rapidly increasing demands from agriculture, but even more rapidly increasing demands from other sectors such as urbanization, industrialization, recreation, and environmental management. Increased efficiency of water use in agriculture suggests -73-
two kinds of strategies: (1) to provide and maintain an optimal supply to the crop root zone, and (2) to use the most effective cropping system available for productivity with a minimum of water use. Water resource management strategies should be applied to all cropped areas. There are few if any places where water in the root zone is optimal (not too much or too little) at all times. Increasing the productivity of a unit of water is as important in the humid zones as in the arid regions. A unit of soil moisture from direct precipitation on a farm is potentially as important to agriculture as a unit supplied by irrigation. Systematic research on crop systems in relation to water availability has not been done in any comprehensive sense. Systematic and comprehensive research at benchmark sites using indicator cultivar varieties could expand knowledge of crop systems and their interaction with water and reduce, or make more efficient, adaptive field trials. Physical management to optimize soil moisture involves a cluster of management practices and technology. Depending on climate, weather, soil, and other factors, this may include a mix of irrigation, drainage, land farming, planting and tilling practices, and timing. Some new technological approaches as well as management practices offer promising prospects for maintaining optimal soil- moisture all or most of the time for many farming situations. Payoff from these approaches could be great. Much of the time farmers must live with physical environments that are less than ideal but which cannot be corrected with reasonable economic measures. Examples are: shallow and sandy soils, poor macro-drainage, and inadequate water supply. There is a need to insure efficient use of water under these circumstances. Precipitation around the globe varies widely both in total quantity and in seasonal distribution. Even the most humid regions suffer from moisture deficiencies during part of the growing season. Variability may pose a more difficult management problem than total supply. Agriculture suffers from some kinds of water deficiencies in all parts of the U.S. Improving water supply includes: (a) storing water otherwise wasted in runoff to the sea, (b) using groundwater to increase total supply or to provide supplies congruent with crop needs, (c) providing macro-drainage so that excess water can readily be removed, (d) conserving rainfall on the farm, and (e) harvesting water by watershed management techniques. Quality is an important and neglected element of water supply; which is really measured by the amount of water of usable quality available at a given time. Water supply improvement beyond the limits of the farm requires collective action, and therefore social and political considerations become important. As mentioned earlier, institutions have important effects on agricultural water management. Principal
institutions which both enhance and constrain efficient water management include law, organizations for managing and distributing water supplies, state and federal agencies, and marketing systems. There is a great store of knowledge and information about agricultural water management that is not being used. In the final analysis good water management systems and practices are site-specific. Besides vigorous research, every effort needs to be made to bring the current state of knowledge to bear on at least the critical problems. Pervasive as it is in occurrence, fresh water is nevertheless a scarce resource which is growing scarcer. Its quantity is generally renewable, but its quality may not be. About 4,200 billion gallons of water per day fall on the conterminous United States; 3,000 billion gallons per day evaporate or transpire, mostly by crops or forests. Grain crops alone probably transpire nearly 100 billion gallons per day. Bradley (1962) points out that a pound of bread and a pound of meat per day require 3,000 gallons per capita per day, or, for 200 million people, 600 billion gallons of fresh water daily. The water budget rather than land may really place the more limiting constraint on food supply. Water consumption by irrigated agriculture was estimated to be about 75 billion gallons per day, or 89 percent of all consumptive use and about 59 percent of the total water withdrawn in 1970. According to the U.S. Water Resources Council (1968) , irrigation will constitute only about 19 percent of withdrawals by the year 2000, but will account for about 70 percent of consumptive use. CROPPING SYSTEMS If a cropping system is to be optimized with regard to water supply, more needs to be known about productivity of crops as related to their water regimes. Given desirable cultivars, comprehensive experiments in which more complete and relevant sets of production factors are controlled or measured should be conducted. Few, if any, such experiments have been made. Major benchmark cultivars should be used and experiments designed and instrumented to insure comprehensive intimate environmental information, including weather. The variance due to water stressing at various moisture levels should be evaluated. To achieve the desired results, a comprehensive and systematic experimental approach is needed rather than just adaptive field testing. This will significantly reduce the time required to get results. Even 5 to 10 years of adaptive testing at a single site does not give a good climatic sample. Repeating a comprehensive study at several benchmark sites can add significantly to the total climatic information and provide for better selection of cultivars and other production inputs. A serious deficiency in past cultivar and variety -75-
testing is that phonological history has not been recorded. There is a strong interactive relationship between phenological stage and soil moisture and temperature. The experimental approach should also include pro- ductivity response of various cultivars to production factors at optimum soil moisture conditions in addition to measurement and evaluation of the prevailing specific site moisture regime. Benchmark genetic cultivars can be used so that the large number of commercially available strains need not be individually tested. Relating known genetic makeup of cultivars to pertinent environmental variables will markedly improve the ease with which technology can be transferred from one region or country to another. SOIL WATER MANAGEMENT SYSTEMS Emphasis should be placed on developing technologies that involve total agricultural water management aimed at providing delivery of water to the crop root zone when it is needed by the crop, or in removing water from the root zone when it is in excess. In the past, the practices of irrigation and drainage have been largely considered separately. Water management for optimal moisture conditions for crop growth requires that they be considered together. Land surface modification is an important consideration in both removing excess water and attaining efficient irrigation. Timeliness is perhaps one of the most critical items in the production process from the standpoint of both drought and excess water on the land. Scheduling of irrigation based on environmental factors holds great promise in determining the frequency and amounts of application to meet crop needs quite independent of the irrigation method. Computerized techniques provide the capability for rapid evaluation of crop needs and rapid mass distribution of management decisions relative to both water and fertilizer applications. Combined irrigation and drainage systems coupled with instrumentation for moisture-sensing feedback offers real potential for high frequency optimal soil moisture control. Optimizing with respect to soil moisture for different soils, climates, topographies, and similar factors shows great promise for expanding the land resource base for certain crops as well as increasing yields. Energy requirements as well as cost will be an in- creasingly important consideration in the development of effective water management systems throughout the world. A major problem of wet soil is its resistance to traffic and the constraints this places on planting and other farming operations on the land. Strategies should be researched which will reduce the need to till or get on the -76-
land with heavy equipment. These will not only improve operation efficiency, but will reduce both sheet erosion and costs. Soils are often overdrained in order to permit traffic in the wet season, and valuable water needed at later critical times is lost. Another objective of water management on the farm is to conserve nutrients in the soil and reduce the return of salts and the erosion of soil and sediment to rivers, streams, and lakes. This objective is important in part because of specific quality and emission standards enforced or to be enforced under the National Environmental Protection Act. Irrigation and drainage practices, especially under arid conditions, have a direct bearing on the salinity and sodium of agricultural lands. Crop production is seriously limited in many areas of the U.S. as elsewhere in the world by excess salts or high sodium soils. In addition to the relation of water quality and soil salinity to crop yields, the water management region has an important effect on the quality of return flows and the amount of salts returned to river systems. There is strong experimental and theoretical basis for the possibility of precipitating salts in the soil profile and thus rendering them harmless to crops. Salts thus precipitated are immobilized and kept from returning to the water supply of the river system. The key to this process appears to lie with the ability to adequately control irrigation and reduce the leaching fraction to a low level. The potential for conserving water through improved practices and the benefits to be derived from reducing the salinity hazard deserves evaluation in various arid regions. Implementation The technology for various irrigation and drainage systems has reached a relatively advanced stage. New developments have been made in surface irrigation, sprinkler irrigation, trickle irrigation and open ditches, and in tile and corrugated plastic drain tubes and well drainage. There are many promising avenues that should be researched under a wide variety of site conditions. In order to achieve efficiency and coordination of effort, new or existing centers of excellence in several geographical areas should be given adequate support. WATER UTILIZATION IN NON-OPTIMAL CROPPING SYSTEMS Agriculture will always be faced with physical conditions that are not optimalâand in some cases substantially less than optimalâas far as water management is concerned. The following deals with some of the most -77-
pervasive and difficult conditions under the assumption that it will be desirable to keep some of the land characterized by such conditions under production and to insure some reasonable economic return to the farmers. Low Quality Supplies Salinity may inhibit plant growth at levels as low as several hundred parts per million (ppm) in the water supply under poor management conditions. On the other hand, with optimal conditions, economic crops may be grown with water supply concentrations as high as 5,000 to 6,000 ppm. As river systems are used, salinity concentration will increase upstream to downstream. Large reserves of groundwater are also saline. Both situations exist, not only in the U.S., but all over the world, and effective use should be made of them. Two approaches are needed. One is to develop cultivars that are increasingly salt tolerant. This approach has been touched only barely and deserves increased effort, possibly at a national or international center. The other approach is through management on the farm involving irrigation and drainage practices that reduce or control osmotic stress, prevent adverse ion adsorptions, and involve appropriate tillage and other cultural practices to reduce salt crusting and insure germination. Much is already known about management of low quality waters so that this may largely involve adaptation to specific sites. Some experimentation needs to be continued on management practices, however. Severe Irrigation Water Shortage Climate and weather variation is great, especially in arid lands, and strategies need to be devised which take into account risks and benefits. This is an area where improved weather forecasting and and more drought resistant crop varieties would be useful. (See Chapter 10, The Climate and Weather Resource.) Soils with Low Water-Holding Capacity Soils with low water-holding capacity include extremely sandy soils and shallow soils. In most cases, frequent irrigation is the obvious solution, and some specialized irrigation technology has already been developed that is useful for maintaining a satisfactory soil-water regime. Most cases may simply require application of available technology, but consideration should be given to the need for research on this topic. -78-
Drought Hazard Drought is a major hazard to agriculture. Ability to predict climate and weather on a long-range basis would be extremely useful in managing drought-prone areas. Many of these areas are grazed, and information on climate and weather variability is needed to design management strategies for grazing. TECHNOLOGY AND MANAGEMENT FOR WATER SUPPLIES Efficient water management on the farm may often be impaired or rendered useless because of conditions beyond the farm boundary. This is particularly true where irrigation and drainage are required. In these cases the system is beyond the control of the farmer and dependent upon common action at some level of society. Farmers may, however, be able to conserve moisture on their own cultivated lands or on watersheds under their control. Storage of surface water in reservoirs is the principal approach to insuring supplies during dry periods whether the farms lie in the arid western U.S. or the humid regions of monsoon Asia. Engineering technology for providing such storage is well advanced, but primarily in arid lands. Increased attention needs to be given to improved technology and management practices for storage reservoirs, particularly for smaller reservoirs in sub-humid and humid regions. This is both an engineering problem (adequate and safe structures) and a hydrological one (optimal amount of storage under conditions of stochastic and spatial variation). Groundwater reservoirs contain a vast amount of water in storage. These may be used to stabilize supplies from other sources in much the same way as surface reservoirs, but they may also be withdrawn at greater rates than they are replenished. The High Plains of Texas is a primary example of groundwater mining. Well technology and methods for assessment of aquifer potential and for recharge should be improved. Perhaps one of the major reasons for inefficiency of irrigation is inadequate systems for distribution of water to farmers in the right amount at the right time. This problem is often partly social and, in regions that are highly developed and where units are small, poses serious right-of-way problems. Research is needed to produce more effective arrangements and design, control and measuring structures and use of new materials, particularly inexpensive enclosed conduits. A nation's or region's water supply is really measured by the amount of water of adequate quality available to meet needs at any given time. Increasing or enhancing our supply through improvement or safeguarding its quality can pay -79-
large dividends. Reuse of municipal and industrial waters has not been practiced extensively in agriculture because of uncertainty regarding the fate of bacteria and viruses and the long-term impact of various heavy metals and nutrients on soils. Research should be directed toward reenhancing these waters and reusing them either directly or through groundwater recharge. Conservation of water supplies in surface reservoirs, in the soil, or through water harvesting is of great importance. Little practical progress has been made in reducing surface evaporation from reservoirs. The use of monomolecular layers or some other surface covering, especially on small reservoirs, needs further exploration (Hughes et al. 1974). Recent preliminary computations indicate that turning over the stratified levels of deep reservoirs using air or some other means to bring this cool water to the reservoir surface could substantially reduce evaporation. More emphasis needs to be given to conserving soil moisture by tillage, by ground covering, or by modification of micrometeorology using windbreaks or shelters, especially in semi-arid plains regions. Intercropping appears to be one of the more effective ways to modify micrometeorology. This approach has had very little attention. Water harvesting, i.e., increasing runoff by changing the surface infiltration or plant cover, is a promising means for increasing surface supplies. Runoff farming, a process that accumulates sufficient water from a large area onto a contiguous small one, has been practiced for centuries. Increasing attention needs to be given to improved materials and methods of water harvesting. There are a number of relatively simple ways to conserve water that could be easily implemented in arid lands around the world (NAS 1974). Finally, weather modification by cloud seeding to enhance precipitation could enhance water supplies by adding soil moisture and increasing runoff. (See Chapter 10, The climate and Weather Resource.) The water regime of rangelands is a major element in livestock production. There is potential for significant improvement in the availability of drinking water for animals. Water harvesting research should be aimed at cap- turing and concentrating water to allow animals to secure water but spatially distributed so as to minimize both animal travel and the excessive trampling of feed near the water hole. A second area of increased production potential on rangelands is in the selection and/or breeding of both grasses and shrubs that are palatable, nutritive, and water efficient for the water regimes typical of rangelands. -80-
CONSTRAINTS ON WATER MANAGEMENT Improving efficiency of irrigation water use may be limited by institutional arrangements, including water rights laws and their administration. In most of the western states public waters may be appropriated as private use rights if diligence is exercised in constructing works and the waters are used beneficially. Priority of rights is based on time of filing, but great leniency has been exercised in proof of diligence and in regard to efficient use. Normally water rights may be transferred by purchase and sale if the public interest is not impaired. Even so, water-rights laws and their administration are highly complex, and research is needed to consider what changes should be made to foster greater efficiency. This is especially true considering increased competition by energy development and urbanization for water supplies. Laws governing groundwater are often inconsistent with surface water laws. A different, and often poorly related, legal approach is being taken to water quality. The legal basis for irrigation water rights in the sub-humid and humid states is at a less developed stage than in the arid West. Attention needs to be given to how laws and regulations might be improved to encourage efficient use of water and insure its availability for agriculture insofar as possible. Laws relating to water quality need to be formulated realistically so that efficient agricultural practices are not constrained more than is socially desirable. Laws are only one element in the institutional arrangements concerned with water. Organizations for delivering water and their rules, regulations, and pricing arrangements represent another major class of institutions whose operations have significant bearing on efficient management of water supplies. Other important examples include the process of public planning and decision making with regard to water systems and related land use, the structure and role of federal and state agencies, and the water market. We need greater understanding of how these institutional processes and laws and regulations can be improved. SELECTED REFERENCES Bradley, C.C. (1962) Human Water Needs and Water Use in America, Science, 138 (489-91), October 26. Hagan, R.M., H.R. Raise, and T.W. Edminster, eds. (1967) Irrigation of Agricultural Lands. Am. Soc. of Agronomy, Madison, Wisconsin. Hughes, T.C., E.A. Richardson, and J.A. Fronchiewicz (1974) Water Salvage Potentials in Utah. Vol. 1. PRWA22-1 Utah Water Research Laboratory. Logan, Utah: Utah State University. -81-
National Academy of Sciences (1968) Water and Choice in the Colorado Basin. Washington, D.C.: National Academy of Sciences National Academy of Sciences (1974) More Water for Arid Lands. Promising Technologies and Research Opportunities, Report of an Ad Hoc Panel of the Advisory Committee on Technology Innovations, Board on Science and Technology for International Development. Washington, D.C.: National Academy of Sciences. National Water Commission (1973a) Water Policies for the Future. Washington, D.C.: U.S. Government Printing Office. National Water Commission (1973b) New Directions in the U.S. Water Policy. Summary and Recommendations. Washington, D.C.: U.S. Government Printing Office. Peterson, D.F., ed. (1973) Research Needs for on-Farm Water Management. Logan, Utah. Schilfgaarde, J. van (1974) Drainage for Agriculture. Am. Soc. of Agronomy, Madison, Wisconsin. Rawlins, S.L. and P.A.C. Raats (1975) Prospects for High- Frequency Irrigation, Science, 188 (4188): 604-610. U.S. Water Resources Council (1968) The Nation's Water Resources. Washington, D.C.: U.S. Government Printing Office. -82-
CHAPTER 9 FERTILIZER RESOURCE RECOMMENDATIONS Efficient Fertilizer Use. Studies should be implemented on improving the efficiency of fertilizer nutrient use. Programs for Heavily Fertilized Soils. Phosphate and potash fertilizer programs should be developed for heavily fertilized soils. Ammonia. Technology to produce ammonia from coal should be developed. Phosphate Rock. Studies should be made of more efficient extraction of phosphates for fertilizers. INTRODUCTION Fertilizer is essential in maintaining or increasing food production. Fertilizer is needed to help developing countries in their struggle for food self-sufficiency. And it is needed in increasing quantities in developed nations to sustain production and to produce surplus food which can be shared (Nelson, in press). Worldwide interest in fertilizer has intensified as its role in food production has become better understood. Estimates generally indicate that 30 to 40 percent of the increased agricultural production in this country during recent years is directly attributable to increased use of fertilizer. In developing countries, where soils are less fertile, fertilizers can be even more important, expecially on crops of high yield potential. On the average, 1 kilogram (kg) of nutrients increases rice yields 10 kg and wheat 8 kg in developing countries. Improved varieties give even greater returns. However, fertilizers aloneâwithout use of improved cultural practicesâcan increase production only modestly, if at all. There seems to be little doubt that our ability to feed ourselves depends in considerable part on how abundantly we can make more efficient and reasonably priced fertilizers available to the world's farmers. -83-
Fertilizer technology research and development in the U.S. is conducted largely by the Tennessee Valley Authority (TVA) at its National Fertilizer Development Center. The U.S. fertilizer industry conducts very little research on its own. Recently, an International Fertilizer Development Center (a nonprofit organization entirely separate from TVA) has been set up at Muscle Shoals, Alabama, to develop technology specific to the needs of developing countries. The USDA and the land grant universities traditionally have conducted research on fertilizer use, soil testing, and similar studies, but in recent years their research effort on fertilizers has decreased. In general, the level of fertilizer technology in the U.S. is high, possibly leading the world. New problems of major importance, however, have risen in the last couple of years which demand immediate attention and are included in the above recommendations. First, until very recently fertilizers have been in short supply and are high in price in the U.S. and worldwide, indicating the need for developing ways to use fertilizers more efficiently. Recommendations 1 and 2 deal specifically with this. Second, shortages of raw materials needed in fertilizer manufacture have developed, particularly natural gas for ammonia synthesis (see Recommendations 3 and 4). Third, a great concern has developed about food shortages in developing countries, coupled with the fact that the major input, fertilizer, has been developed solely to meet the needs of temperate zone soil and crops. These problems are critical, and to solve them will require funding the RSD effort at a higher level than in the past. EFFICIENT FERTILIZER USE Rationale A worldwide problem is the low recovery of fertilizer nutrients by plantsâusually averaging only about 50 percent of the applied nitrogen and 30 percent or less of the applied phosphate. Losses may be even greater on certain tropical and subtropical soils. There is strong evidence suggested by TVA that recovery and efficiency can be improved by coating nitrogen fertilizers to impart slow- release properties (such as sulfur-coated urea) and by using improved application methods and timing. There is a real need to develop and install methods and soil management practices involving alternatives to inorganic sources of nitrogen such as legumes in crop sequences or as cover crops and organic sources such as animal and human wastes. (See Chapter 11, Energy Resource.) This is a high priority problem. A 10 percent increase in nitrogen efficiency, which might be easily achieved, would save the world nearly 4 million tons of nitrogenâthe -84-
nitrogen input for 40 million tons of cereals. In addition, more efficient use means less nitrogen lost through leaching into groundwaters thus improving the environment. Implementation A concerted, immediate research effort is called for. Stable nitrogen isotopes and radioactive phosphorus, both available, should be used. Field and laboratory investigations and, probably, construction of pilot plants to produce new fertilizers would be required. PROGRAMS FOR HEAVILY FERTILIZED SOILS Rationale Large residual reserves of phosphorus and potassium build up in soils that have been heavily fertilized. U.S. farmers tend to continue heavy fertilization, presumably resulting in inefficient fertilizer use. Field experiments, coordinated with soil tests, need to be conducted to determine whether phosphate and potash use can be safely reduced without endangering crop yields and, if so, how much and under what conditions. Considerable fertilizer might be saved for use elsewhere, besides decreasing fertilizer costs to the farmer. This is a major problem in the U.S. and industrial countries. In the U.S., for example, about HO percent of soil tests indicate that high fertility conditions exist. However, there is some reason to doubt whether soil tests adequately measure the nutrients available to plants under today's high fertility agriculture. The U.S. uses about 4.6 million metric tons of P2°5 i° phosphate fertilizer, and 4.5 million of K20 in potassium fertilizer. Possibly 20 percent of this fertilizer is used on soils where it is not needed. Saving this amount of costly fertilizer would be of considerable monetary benefit to the U.S. farmer and would release U.S. produced phosphate to world trade and improve the balance of payments (the U.S. is a large net importer of K_0) . Implementation A research effort involving field research on this problem has already been started by TVA and the land grant universities, and it should be quickly expanded. -85-
AMMONIA Rationale Essentially all U.S. ammonia production is based on natural gas as a feedstock. The U.S. does not now produce sufficient natural gas to meet demand, and the projection is that the shortage will increase. Fuel oil or naphtha can be used to produce ammonia instead of natural gas, but the U.S. is also short of these. Obtaining hydrogen or methane from coal is an alternative process. Several developmental projects related to coal gasification are underway in the U.S.; however, these projects will not produce a gas suitable for ammonia production. Proprietary German technology is available that will permit ammonia production, but the processes need considerable improvement and are extremely costly to install and operate. New, modern technology available to the U.S. and developing countries is badly needed. Since U.S. coal reserves are abundant, the development of an efficient means for producing ammonia feedstock from coal is seen as a practical necessity. The development, optimization, and demonstration of this technology for U.S. coals is expected to be expensive and may require up to 10 years. With the current and pending situation on natural gas and petroleum-derived feedstocks worldwide, there is no choice but to go to coal. In fact, the future of the world food situation may hinge upon developing low cost and adequate technology using coal as a feedstock for ammonia synthesis. Implementation The problem would have to be attacked by a large, chemical and engineering oriented organization such as TVA. PHOSPHATE ROCK Rationale Phosphate rock is the sole source of phosphates for fertilizers. Currently, there are only a few major phosphate ore reserves in the world which are mineable. New deposits, mostly low grade and marginal in nature, are being found around the world, many in developing countries. Essentially there are two problems with the use of phosphate rock. -86-
1. Mining Recovery Currently, only 40 to 60 percent of the phosphate in ore is recovered in mining operations. Phosphate in slimes discarded in the washing operations probably is irretrievably lost, and in addition slimes present a difficult environmental problem. Research is needed to identify the chemical and miner- alogical composition of slimes, to determine how to recover more phosphate during washing, and to determine ways to dehydrate remaining residues so that they will solidify and not cause environmental difficulties. 2. Marginal and Low-grade Ores High-grade ores in Florida are being exhausted rapidly: their life is expected to be only around 30 more years. Many countries, including developing countries, have deposits of low-grade ores not now considered mineable because of their low phosphate content and undesirable mineral properties. Ways need to be found by which these lower grade ores can be used either through beneficiation or chemical processes. Implementation There is some research in this area contemplated by TVA and the International Fertilizer Development Center. This is a high priority problem, and chances for its solution are good. Solving the problem would extend the life of the Florida deposit possibly for another 20 years and would be of great value to many developing countries in that they could use their own lower grade ores rather than buy high- priced ores on the world market. Research strategy would involve laboratory studies of deposits, beneficiation tests, and a pilot plant. SELECTED REFERENCES Nelson, L.B. (in press) Fertilizers for Ail-Out Food Production. Ail-Out Food Production: Strategy and Resource Alternatives. Special Publication, American Society of Agronomy. U.S. Department of Agriculture (1974) United States and World Fertilizer Outlook: 1974 and 1980, ERS, February. -87-
CHAPTER 10 THE CLIMATIC AND WEATHER RESOURCE RECOMMENDATIONS 1: Weather Information. A weather advisory system should be established to provide weather information, including seasonal and longer term forecasts, for the efficient management of the agricultural enterprise. 2: Impacts of Weather Variability and Climatic Fluctuations. Field studies and statistical studies should be initiated on the impact of weather and climate fluctuations on food, water, and energy supplies. 3: Weather Modification. Research should be intensified to determine the necessary atmospheric properties for rainfall augmentation and hail suppression on agricultural and forest lands. INTRODUCTION The atmosphere's reservoir of oxygen, carbon dioxide, and gaseous water provides life support to biological systems. The motion or circulation of air provides the mechanisms for cycling and transporting the water vapor, carbon dioxide, and other gases. The biological systems are driven by the solar radiation penetrating the atmosphere. Many atmospheric properties are important elements in food production. Temperature controls the speed of biological reactions. High humidities favor crop diseases and insects: for example, in 1971 a serious leaf blight attacked the corn crop as a result of high humidities throughout the central U.S. Atmospheric moisture also affects the quality of grain during harvest and storage. Atmospheric turbidity and cloudiness determine the amount of solar energy reaching the plant canopy. Perhaps the most important contribution of weather to food production is its effect on the balance of water between the supply from rain and the demand from evapotranspiration. The droughts of the thirties and fifties and more recently in 1974 brought widespread damage to major food producing regions of the Midwest. Although excess water at planting and harvesting times has an adverse effect on field operations, for most -88-
agricultural systems the availability of water during critical periods of the growing season increases the chances of an abundant harvest. WEATHER INFORMATION Rationale The system for agricultural production in America and other major granary regions has become more complex with improved agricultural technology. The increased use of fertilizers, high potential genetic stocks, and mechanization has produced management systems requiring more sophisticated strategies for operating the farm. These management systems are more sensitive to weather events than the simpler schemes of other areas. The farm investment in mechanized agriculture must fit the climatic conditions of the area. Day-to-day decisions by farm managers require correct interpretation of short-range weather outlooks. Changing climate and fluctuating weather add a further complication to the impact of weather on the farm enterprise. The selection of alternatives in long-term investments (20 to 30 years payoff) should include evaluations of climatic trends, the possibility of the nonrandom character of weather events (such as drought), and variabilities in weather (such as rainfall and temperature). Some of these farm operations involve environmental issues. Examples of major farm decisions sensitive to weather can be cited. 1. Day-to-day operational decisions by farm managers for immediate management of planting (soil temperatures), harvesting (grain moisture content), other crop and animal production, and the marketing and storage of farm products require critical and timely weather information. Specialized services providing "real time" weather information and forecasts are required throughout the year. 2. The design and operation of efficient pest manage- ment systems rely on accurate interpretation of the micro- meteorological conditions favoring weed, spore, or insect development and the dispersion of pesticides into a turbulent atmosphere. 3. Hydrologic systems for handling feedlot waste are based on the climatic expectance of intense rainfall. U. The availability of solar energy for the drying of fields, drying hay or grain, and human or animal protection is related to weather conditions. Energy from wind is also an attractive alternate energy source on farms. 5. The design and operation of water management systems depends on proper interpretations of short-range weather outlooks. Capacity and operation of an effective irrigation system depend on the climate assessment and short-range weather forecasts. -89-
6. The design and operations of hay and grain drying facilities require information concerning humidity, tempera- ture, and other weather events. The nationwide program providing weather information to agriculture both increases production, conserves energy, and reduces crop and livestock losses. In June 1975 a special panel of the Agricultural Research Institute reaffirmed an earlier position that crop and livestock losses could be minimized by increasing and improving weather forecasting services to farmers. The program would reduce the hazards of pollution by promoting a proper design of pest management and hydrologic systems. Implementation A system for specialized weather services for agriculture is required to increase production, improve efficiency, and limit environmental hazards. The system would draw on the reservoir of knowledge, current research, available climatic data, and weather forecasts. This program should include implementation of the pro- visions of the current federal plan for improved weather services to agriculture, with immediate expansion to na- tionwide coverage of the agricultural forecasting program of the National Weather Service. Responsibility for information dissemination and adult education for farmers resides in the USDA and its state cooperators. The Cooperative Extension Service is the best information distribution agency for agriculture. This extension program will provide liaison support with the service offices of the National Weather Service. Although the extension program will support the Agricultural Meteorological Service offices, where they exist, the implementation could proceed prior to the completion of the nationwide agricultural program by the National Weather Service. IMPACTS OF WEATHER VARIABILITY AND CLIMATIC FLUCTUATIONS Rationale Much has been said about the recent trends in climate. There is well documented evidence that warming of the polar and mid-latitudes occurred during the first half of this century, and these same areas have been cooling since the early 1940s. Associated with these recent trends, many of the northern agricultural areas have experienced cooler summers, shorter growing seasons, and lower moisture demand. It is not certain that the decline in temperatures will continue; the decline may halt or reverse itself. However, one of the risks in food production is the variable and fluctuating character of climate. Additional evidence -90-
indicates that seasonal rain has decreased in many tropical areas. In other regions of the world, a more favorable rainfall pattern may have occurred. The year-to-year and seasonal variations in rainfall provide a major impact on plant growth and development. Implementation The effects of fluctuating climate and weather on agricultural production should be determined. The current evaluation technique involves correlation between historical yields and concurrent weather events. These statistical studies are providing a general relationship for predicting the effects of weather on the yields. To estimate the impact of the variable climate and weather on food production, contingency studies using the climatic information from the historical data bank will be necessary. To further sharpen the estimates of yields from weather information, field experiments designed to specifically study weather/crop yield relationships must be undertaken. Since these experiments must focus on the water balance at critical stages of plant development, the experimental design must provide varying water stress during these periods for crops grown under current technological development. The use of earth resource satellites for assessing worldwide crop conditions is being studied through the Large Area Crop Inventory Experiment (LACIE). LACIE will provide a critical assessment of the potential for using satellites in evaluating the world's food production. WEATHER MODIFICATION Rationale Weather modification for the purpose of augmenting natural rainfall has been practiced in the Western U.S., the Great Plains, and the U.S.S.R. for more than 25 years (NAS 1973). Results from the cloud seeding activities have been both promising and disappointing. Some experiments have reported increases of 10 to 20 percent above the natural rainfall. Many modification programs have not provided a demonstrable change in rainfall; while others, notably the Whitetop Experiment in Missouri in the early 1960s, have experienced less rain in the seeded areas. There have been several reports of significant increase in snow packs from winter seeding in mountain regions. The reduction of the intensity, size, and frequency of hail storms through cloud seeding offers an additional com- ponent to weather modification. In selected agricultural areas reduction of hail damage to crops is a significant -91-
economic goal. Many cloud physicists and experimentalists are confident that weather modification technology for hail abatement is either currently available or will become usable within the present decade. The return from the development of a dependable cloud seeding technology for rain augmentation and/or hail abatement will be great. The benefits were enumerated in the report on "A National Program of Research for Weather Modification" of the joint Task Force of the USDA and State Universities and Land Grant Colleges released in 1968. The gain to agriculture will be from the prospect of stabilizing the water supply for agriculture and the promise of hail abatement. Since the cost of seeding clouds is small compared to other inputs to the agricultural enterprise, the economic importance of a dependable system could be extremely valuable. It appears that not enough is now known about the optimum microphysical conditions of the cloud or of the stability properties of the atmosphere in which the cloud is imbedded to project success or failure of a seeding operation. Implementation In some limited applications implementation of the technology of weather modification can responsibly start now. For most uses, additional research in cloud physics and cumulus dynamics is required before the full potential of weather modification will be realized. In addition to laboratory experiments, major field trials are still required. High priority should be given to field experiments in the High Plains (rain augmentation and hail suppression) and in the midwestern and southeastern U.S. for convective clouds in summer. Existing research groups, such as the National Center for Atmospheric Research, the Bureau of Reclamation, and the atmospheric science laboratories of the major universities, should be assigned responsibility for this research. SELECTED REFERENCES Hare, K., ed. (197U) Weather and Climate Change, Food Production and Interstate Conflict. New York: The Rockefeller Foundation. National Academy of Sciences (1973) Weather and Climate Modification Problems and Progress. Committee on Atmospheric Sciences. Washington, D.C.: National Academy of Sciences. National Academy of Sciences (1975) Understanding Climatic Change: A Proqram for Action. United States Committee for the Global Atmospheric Research Program. Washington, D.C.: National Academy of Sciencess. -92-
National Oceanic and Atmospheric Administration (1973) The Influence of Weather and Climate on United States Grain Yields. Bumper Crops or Droughts. A Report to the Administrator for Environmental Monitoring and Prediction. November 14. U.S. Department of Agriculture (1968) A National Program of Research for Weather Modification. Prepared by a joint task force of the U.S. Department of Agriculture and the State Universities and Land Grant Colleges. -93-
CHAPTER 11 ENERGY RESOURCE RECOMMENDATIONS 1: Energy Flows. Studies should be undertaken to determine and characterize the types of energy flows throughout the system of production, processing and distribution, and utilization of our food and feeds. 2: Substitutes for Nitrogen Fertilizers. Research is needed for developing effective and economical substitutes for commercial nitrogen fertilizers, such as animal wastes, legumes and green manures, and sewage sludge. 3: Conservation of Energy. Management programs should be developed to conserve energy on the farm. INTRODUCTION Energyâlike land and waterâis a vital resource in food production. The U.S. food system (production, processing, distribution, and preparation) uses from 12 to 15 percent of our annual energy budget. With the availability of an abundant supply of relatively low cost energy, the U.S. food system has become energy intensive. The application of energy has focused on increased unit pro- ductivity on our farms and ranches, the supply of a wide spectrum of wholesome and nutritious consumer products, and the release of a major portion of our population from menial, tedious, and economically unrewarding tasks. Of the energy currently being used in the U.S. food system, it is estimated that one-third is used for production, one-third for processing, and one-third for preparation and distribution. The quantification of the forms of energy used by the major operations of the system would permit identification of the substitutability of more abundant forms of energy for the nonrenewable short supply energy forms currently being used. The characterization of the energy use would help to identify relationships between energy inputs and the quantity and nutritive values of the outputs, thereby providing opportunities to conserve energy and develop alternative practices. -94-
The pressure of human population on land, energy, and water resources is now greater than it has ever been before. Man's use of energy to manipulate and manage his environment is probably the most significant factor in the rapid growth of the human population. The exponential increase of human numbers directly coincides with the use of fossil energy. In particular, energy has been used to reduce human death rates by effective public health measures and to supply the food needed by an increasing population. Energy and food are in short supply today primarily for the same reasonâthe growing number of human beings. It is interesting as well as significant that energy use has been increasing faster than world population. The U.S. population doubled in the past 60 years, but our energy consumption doubled in the past 20 years; the world population doubled in the past 30 years, but the world's energy consumption doubled in the past decade. Because most of the energy is being supplied by non- renewable resources, fossil energy reserves are rapidly disappearing (Figure 1). Known world reserves of petroleum and natural gas are expected to be more than half depleted in the next 25 years (year 2000), and more than half of the coal reserves are estimated to be depleted about the year 2100âshortly before the world reaches its projected maximum population density in the year 2135. While the recently expanded efforts to find new reserves of petroleum fuels and to develop new energy technologies to permit use of more abundant forms of energy will help to alleviate the short supply of energy, opportunities exist for obtaining information to provide a basis for: assessing the impact of national policies on the food production system; determining the effects of conservation and/or alternative practices on energy use; and establishing long-range research priorities with the greatest potential for increasing the effective use of energy resources for food production. ENERGY FLOWS Rationale Production, processing, distribution, and consumption of food for the sustenance of the people of the U.S. reguire high levels of energy subsidy. Improved species, varieties, cultural practices, and management have been contributing factors to our successful production system; however, all are dependent on the ever increasing energy applied to the total system. The dependence of the national food system on abundant, low-cost sources of energy has created a high level of vul- nerability to severe disruptions when energy supplies are curtailed and there are sharp increases in the prices. Fuel -95-
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shortages may be catastrophic to the system as was demonstrated in Iowa in 1973 when insufficient LP gas for drying the crop caused delay of harvest and a loss that at one time was estimated to be as much as 10 million bushels. Although the national system has become highly depend- ent on abundant, low-priced sources of energy, the consump- tion patterns within each segment of the system, while ex- tremely critical, are not well known. Even the total magnitude of energy utilization is not well-defined as indicated by varying quantities being reported in the numerous documents discussing the U.S. energy budget. Knowledge about the energy utilization characteristics for specific operations is essential to ascertain substi- tutability of currently available energy forms and to permit orderly transfer of new energy technology under development. Information about the interrelationships among the major energy consumption operations will also aid in modifications of current practices and/or development of alternative methodology (i.e., the condition of grain at harvestâmois- ture content, cleanness, and so on). Implementation A two-phase study should be conducted under the direction of a national research organization. Phase I would be devoted to assessing the energy characteristics (magnitude, forms, time and spatial distributions, and the interdependence of major operations) of the U.S. food system. Phase II would involve detailed analyses of the information obtained in Phase I and the development of alternative strategies for the system with changes of inputs. The analyses should include the assessment of the impact of national policies on the total system and the assessment of research priorities for utilizing new energy technologies and the energy potentials in agriculture products and by-products. SUBSTITUTES FOR NITROGEN FERTILIZERS Rationale The single largest input in corn production and second in other crops is fertilizer; nitrogen requires the largest quantity of energy to produce (Table 1) . A potential fertilizer source is the small percentage (about 10 percent) of livestock manure that is not now being used in crop production. Also a significant amount (as much as 50 percent) of nitrogen is lost from animal wastes that are stored and/or applied improperly. Chemical fertilizer is applied to corn at an annual rate of 112 pounds of nitrogen, 31 pounds of phosphorus, and -97-
Table 1 - Energy inputs in corn production (fully mechanized in the USA) (revised after Pimentel et al., 1973). Input Labor Machinery Fuel Nitrogen Phosphorus Potassium Seeds Irrigation Insecticides Herbicides Drying Electricity Transportation Total Corn yield Kcal return/kcal input Quantity/ha 22 hrs 1,037,400 kcal 206 liters 125 kg 35 kg 67 kg 21 kg 187,720 kcal 1.12 kg 1.12 kg 296,400 kcal 380,000 kcal 172,900 kcal 5,080 kg 457 kcal/ha 1,037,400 2,060,000 1,897,500 111,650 147,400 147,840 187,720 82,400 82,400 296,400 380,000 172,900 6,603,610 17,881,600 2.71 -98-
60 pounds of potassium (Table 1). A like amount of nitrogen is available from manure produced during one year by either one dairy cow, two young fattening beef cattle, nine hogs, or eighty-four chickens. In addition to the nutrients manure adds to the soil, it adds organic matter which increases the number of beneficial bacteria and fungi in the soil, makes plowing easier, improves the water-holding and percolation capacity of soil, reduces soil erosion, and improves the ratio of carbon to nitrogen in the soil. The major costs of using manure for crop production are hauling and spreading. Hauling and spreading manure within a radius of 1/2 to 1 mile (1 mile =1.6 kilometers) is estimated to require 1.1 gallons of gasoline per ton. If the average manure application is 10 tons per acre (produced by one cow for one year), an estimated 398,475 kcal (11 gallons of gasoline) per acre is necessary to apply the manure and hence to fertilize corn with manure. Producing chemical fertilizer (112 pounds of nitrogen, 31 pounds of phosphorus, 60 pounds of potassium) for one acre requires a total of 1,415,200 kcal. One gallon of gasoline is used for tractor application, therefore a total of 1,451,425 kcal for chemical fertilizer application is used. Hence, if manure were substituted for chemical fertilizer, the savings in energy would be a substantial 1.1 million kcal (about 28 gallons of fuel) per acre. Current U.S. livestock manure production is estimated to be 1.7 billion tons per year, over 50 percent of which is produced in feedlots and confinement rearing situations. If 20 percent of the manure produced in feedlots and confine- ment rearing situations were available for use in crop production, about 170 million tons of animal waste would be available for crop production. Nitrogen fertilizer inputs can be reduced by planting legumes in rotation with corn and other crops. For example, it is possible to plant legumes between corn rows in late August and to plow this green manure under in early spring. In the Northeast, seeding corn acreage to winter vetch in late August and plowing the vetch under in late April yielded about 133 pounds of nitrogen per acre. A cover crop also protects the soil from wind and water erosion during the winter and has the same advantages as manure in adding organic matter to the soil. The energy cost of seeding a legume would require about 90,000 kcal per acre (fuel and seeds). For the commercial production of 133 pounds of nitrogen, 917,000 kcal are needed; thus the energy saved by planting a legume for green manure would be substantial or 827,000 kcal/acre (about 37 gallons of fuel). Instead of inter-planting a legume with corn, another possibility would be to inter-plant corn in a perennial legume field. Preliminary experiments have been made with inter-planting corn in permanent stands of crown vetch. In the early spring the crown vetch is partially killed with an -99-
herbicide. The corn is then planted in the vetch field using "no-till" planting technology. Late in the season the vetch recovers after the corn has made its growth utilizing the nitrogen stored by the vetch during the previous fall and spring. The nitrogen yield is assumed to be similar to that of winter vetch. Although the inter-planting technology can be applied to a relatively few crops, it does have great potential in reducing nitrogen inputs and reducing soil erosion with several important crops. Large quantities of N, P, and K are available in sewage sludge and effluents, but several problems exist before these materials can be effectively used. These problems include: (a) heavy metal contamination in some sewage; (b) possible plant and animal disease organisms being transmitted to the treated crops; and (c) removal of moisture in the material so that it can be transported more economically. The new sewage treatment plants that have installed treatment procedures for the removal of N and P offer the potential of returning these two valuable fertilizer elements to agriculture. Implementation Steps for implementing research on substitutes for nitrogen fertilizers include: (a) comparative studies of the value of animal wastes used directly for fertilizer versus the use for generation of methane gas for the manufacture of fertilizer; (b) research on solving the problems associated with the use of sewage sludge as fertilizer; and (c) research on methodology for using legumes as a means of supplying part of nitrogen requirements for other crops. CONSERVATION OF ENERGY Rationale In addition to the energy used for manufactured input products, such as fertilizer, machinery and packaging materials, energy in the form of solar, electricity, petroleum fuels, natural, and LP gas comprise a large input into the U.S. food system. Various kinds of conversion processes are involved in the application of these energy forms. In the past, primary consideration was directed towards the effective applicability of the energy without optimizing its use. -100-
Agriculture through the ages has been involved in the conversion of the sun's electromagnetic energy into chemical energy through the important biochemical process known as photosynthesis. The manipulation of plants and their environment to maximize the conversion process has been an important factor in the increased production of organic matter by U.S. agriculture. However, the relationship between organic matter production and solar energy availability indicates a very low rate of utilization or conversion. Increased efficiency of solar energy utilization would produce a greater return for other forms of energy inputs into plant production. Machinery and fuel comprise a large energy input in U.S. agricultural production. A viable alternative for reducing the fuel consumption would be to use machinery precisely scaled for a given job and operate it at efficient speeds. The larger tractors and other machinery have been designed to do more work per unit time, but the increase in capacity and the better fuel efficiency at rated loads will be offset if utilized on loads requiring only part of the rated capacity or part-throttle conditions. In general, farmers purchase larger machinery than may be necessary as insurance against inclement weather and to enhance crop yield related to timeliness of operations. The major tillage operations will normally be the governing factor in the size of tractor purchased. Therefore, opportunities exist to reduce the power required for primary tillage as well as the size of machinery necessary for tillage operations. Energy inputs in crop drying have increased drastically the past few years. Since 1945, a 30-fold increase in energy inputs for corn drying has occurred. The trade-off of reducing yields some, but advantages of harvesting a drier corn should be examined. Also the trade-off of harvesting corn on the cob vs. corn grain should be analyzed. With other grains, such as wheat, there is less of a problem with drying but there are also fewer alternatives. Since most grains produced in the U.S. are fed to live- stock, greater quantities of grains are going into "wet- storage." This provides some opportunities for storing grain without drying for about three months. The costs and benefits of this system need investigation. Opportunities exist to improve the drying technology itself. Air temperature, air movement, and time are all factors in determining the most efficient means of reducing moisture in grain while also reducing the energy inputs. Opportunities also exist for breeding grains that have a lower moisture level at harvest. These should be pursued. Irrigation requires a high input of energy. Water is heavy (8.3 Ibs/gal) and large quantities (up to 4 acre feet/acre) are needed for irrigation. The energy requirement to lift this quantity of water 300 feet and -101-
sprinkle irrigate is about 220 gallons of fuel. This is about 20 times the energy required for field operations for the crop. More efficient irrigation practices (e.g., trickle irrigation) can substantially reduce water requirements and energy inputs. Investigations on energy conserving irrigation practices should be increased. Implementation Steps for implementing research on conservation of energy include: (a) greater emphasis on the biochemical process of converting the sun's electromagnetic energy into chemical energy; (b) acceleration of studies on methods to reduce power requirements for primary tillage; (c) development of more efficient grain drying equipment; (d) improvement of storage of high moisture grain; and (e) more efficient means of irrigation. SELECTED REFERENCES Cambel, A.B. (1974) The Energy-Food Delivery System. Paper presented at the annual meeting of the Agricultural Research Institute, Denver, Colorado, October. Chancellor, W.J. and J.R. Goss (1975) Balancing Energy and Food Production 1975-2000. Paper presented at the annual meeting of the American Society of Agricultural Engineers, June. Food and Energy (1975) Farm Electrification Council, Des Moines, Iowa. Freedman, R. and B. Berelson (1974) The Human Population. Scientific American 231 (3): 30-39. Harris, W.L. (1975) Energy. Paper presented at the 141st annual meeting of the American Association for the Advancement of Science in the Symposium - Food, Population and the Environment. Maryland Agricultural Experiment Station Miscellaneous Article, January. Harris, W.L., F.E. Bender, and M.L. Esmay (1974) Agricultural Mechanization as Related to Increased yields and Production. Agricultural Mechanization in Asia, V (1): 22-24, Summer. Heichel, G.H. (1973) Comparative Efficiency of Energy Use in Crop Production. The Connecticut Agricultural Experiment Station, Bulletin 739. Hirst, E. (1974) Food-Related Energy Requirements. Science, 184: 134-138. Hubbert, M.K. (1972) Man's Conquest of Energy: Its Ecological and Human Consequences, pp. 1-50 in the -102-
Environmental and Ecological Forum 1970-1971. U.S. Atomic Energy Commission. Oak Ridge, Tennessee: Office of Information Services. National Academy of Sciences (1971) Rapid Population Growth I-II. Baltimore: Johns Hopkins Press. Pimentel, D., L.E. Kurd, A.C. Bellotti, M.J. Forster, I.N. Oka, O.D. Sholes, and R.J. Whitman (1973) Food Production and the Energy Crisis. Science, 182: 443-448, November. Steinhart, J.S. and C.E. Steinhart (1974) Energy Use in the U.S. Food System. Science, 184: 307-316. United Nations (1973) World population prospects as assessed in 1968. Department of Economic and Social Affairs. Pop. Studies #53. 167 pp. U.S. Department of Agriculture (1974a) The U. S. Food and Fiber Sector: Energy Use and Outlook. Prepared by the Economic Research Service for the Subcommittee on Agricultural Credit and Rural Electrification of the Committee on Agriculture and Forestry, United States Senate, September. U. S. Department of Agriculture (1974b) The World Food Situation and Prospects to 1985. Economic Research Service, Foreign Agricultural Economic Report No. 98, pp. 10-11, 60-71, December. Wittwer, S.H. (1975) Food Production and the Resource Base. Paper presented at the 141st annual meeting of the American Association for the Advancement of Science in the Symposium - Food, Population and the Environment. Michigan Agricultural Experiment Station Journal Article No. 7117, January. -103-
CHAPTER 12 CROP AND LIVESTOCK PROTECTION RECOMMENDATIONS 1: Pesticide Development, Formulation, and Application Technology. Increased effort is essential to develop new pesticides and the technology for their efficient and safe use in order to insure continuing availability of this technology for crop and livestock protection and for inclusion in Integrated Pest Management (IPM) systems. 2: Pest Management Systems. Interdisciplinary teams should be developed of crop protection, plant, and animal scientists to set up crop and livestock production systems which include integrated pest management. 3: Pest Resistant Crops and Livestock. Research efforts should be increased toward the development of pest resistant crops and livestock. 4: Biological Control. Research and development efforts should be increased to greatly enhance the role of biological control agents in reducing pest losses. 5: Innovative Methods. Research should be initiated for innovative methods to regulate behavior, development genetics, and reproduction of pests. INTRODUCTION The term "pest" as used here refers to all noxious organisms, including weeds, plant disease organisms, nema- todes, rodents, insects, birds, and other pests. Similarly, the term, "pesticides" includes herbicides, fungicides, nematocides, rodenticides, insecticides, avacides, predator control agents, and others. Pests take a heavy toll of man's food and fiber. Plant and animal protection problems have become increasingly difficult to solve as agricultural production has intensified. Some pest species serve as vectors of disease producing pathogens which can be destructive to plants and animals. Continuous cropping, monoculture, increased -104-
fertility, irrigation, narrow genetic base crop and livestock types, and centralized feedlots often increase the vulnerability of crops and livestock to pest attack. Estimates of losses of potential crop production in North and Central America due to pests are 28.7 percent (FAO 1970). If we were to add losses that would occur without pesticides and other pest management inputs, total losses would be much greater. In fact, cotton and several horticultural crops cannot be produced commercially without such inputs, and livestock production would be impractical in many areas because of such pests as the screwworm and vector-borne diseases. Losses to pests in the warm tropics are more severe than in the temperate zones. The tsetse fly prevents cattle production in vast areas of Africa. Arthropod and disease organisms must be controlled to permit useful and efficient livestock production in most warm climates. A significant portion of the "Green Revolution" potential for increased food production has been lost to the ravages of weeds, diseases, insects, rodents, and other pests. In addition to field losses caused by pests, we must add postharvest losses. In the U.S. these have been reasonably well controlled by pest management practices in storage and rapid processing procedures. In developing countries postharvest losses are staggering. Microorganisms can quickly destroy most fruits, vegetables, meat, and milk and prevent proper distribution. Aflatoxins produced by microorganisms in such commodities as cottonseed and peanuts can be toxic to man and animals. Insects and rodents destroy grains. Stored grain losses due to pests in India are at least 40 percent. The prevention of even a small part of the worldwide estimated annual loss of 33.8 percent of potential productivity due to pests offers a significant opportunity for increases in the supply of food (FAO 1970). Research, implementation, and educational inputs required to reduce pest losses in the U.S. should be made available quickly. Attempts to prevent pest damage have resulted in the ever-increasing use of pesticides. Although these are generally used effectively in modern agriculture, there are exceptions. There are problems involving pesticide resistance and misuse, destruction of natural controls, environmental contamination, losses of nontarget species, and conflicting recommendations and actions by state, federal, and private sectors. Pesticide misuse and applicator intoxication are serious problems. Nevertheless, the safe use of pesticides remains essential to effective plant and animal protection and is an important component of integrated pest management systems. The need for a systems management approach to crop and livestock production, including protection from pests, based on sound economic, ecological, technical, and societal con- siderations is critically needed. Simplistic approaches to -105-
crop and livestock protection have often been shortlived and, in many instances, have had unwanted side effects. The integrated pest management approach offers the greatest promise for effective, safe, and continuing solutions to pest problems. Integrated pest management (IPM) has been defined as a pest management system that, in the context of the associated environment and the population dynamics and etiology of the pest species, utilizes all suitable techniques and methods in as compatible a manner as possible and maintains pest population levels below those causing economic injury (Glass 1975). IPM tactics include resistant varieties, pesticides, cultural controls, biological controls, autocidal control, attractants and repellents, quarantine, and eradication. The proper employment of these is determined and supported by basic background biological information, economic thresh- olds, modeling, and agroecosystem analysis. The recommendations for research included in this chap- ter have been selected because they are readily implement- able and offer high probability for significantly increasing available food. It should be noted that pests are of worldwide importance. Much of value to pest control in the U.S. has come from scientists and experience abroad. International cooperation in reducing pest movement is essential. Valuable pesticides used in American agriculture and public health fields were developed in laboratories in other countries. Food and fiber products in international trade require special consideration for pest control and/or levels of residues from pest fragments or chemicals. Worldwide control of vectors of disease is of great significance to the U.S. Training of scientists responsible for present and future pest control policies and programs has assumed international importance. All parts of the world community need to be aware of the efforts in other areas that may related to pest management activities. It is not the purpose of this discussion to detail the highlights of international pest management, but these remarks will indicate that failure to review it in more detail is by design and not an oversight. More comprehensive analyses of deficiencies in crop protection and recommendations for improved integrated pest management procedures can be found in the NRC/NAS report, "Pest Control: An Assessment of Present and Alternative Technologies" (NAS, in press) and in other studies on integrated pest management. -106-
PESTICIDE DEVELOPMENT, FORMULATION, AND APPLICATION TECHNOLOGY Rationale Pesticides provide rapid, effective, dependable, and economical means of controlling complexes of major agricultural pests. In many situations their use is known to be effective and without serious ecological effects. The major disadvantages associated with the use of pesticides are adverse effects on nontarget organisms and the development of resistant pest populations. Repeated use of selective herbicides causes a shift in species composition of the treated weed community and allows tolerant species to become dominant. This ecological shift requires rotation of herbicides. There is a great need for expanded research to develop ways to reduce or eliminate the inherent hazards of presently available pesticides and to discover new compounds free of these weaknesses. The problems of pest resistance to pesticides continue to expand and intensify. They are more prevalent and acute among arthropod pests, but a few cases of resistance to herbicides and fungicides have been reported. In the past, resistance problems have been overcome by substituting dif- ferent chemicals in the control program. However, because of the development by single pest species of multiple resistances to several pesticides and a reduction in efforts devoted to the development of new compounds in recent years, effective substitute chemicals are not available for control of some pests. Problems of pesticide resistance and shifts in the species composition of weed population must be met, at least for the present, by introducing effective new pesticides as substitutes for obsolete pesticides. Therefore, efforts to discover and develop new pesticides must be expanded. Also, costly regulatory constraints in registration and use of pesticides must be kept at the absolute minimum required to protect man and the environment. (See Chapter 5, Constraints on U.S. Agricultural Production and Research.) Otherwise, food production may be disastrously disrupted as has happened many times in history prior to the development of modern protection technology. Very substantial improvements in the efficiency, efficacy, and environmental safety of pesticide use can be accomplished through research on formulation and on application technology. Improved formulation and placement of herbicides can reduce environmental contamination and improve the contact with target organisms. -107-
Implementation Implementation of this recommendation is important for just maintaining the present level of pest protection in the U.S. and for improved protection on a number of crops and animals now suffering considerable pest-induced losses. The results will be highly complementary to developing countries because the patterns of pesticide use and availability in these countries often follow those in the U.S. 1. Accelerate research on more narrowly selective pesticides by identifying pests for which availability of narrow spectrum pesticides is most urgent. Strengthen national programs for developing use patterns of chemicals submitted by industry with procedures to safeguard proprietary rights and the public interest. Determine economic threshold densities of pests so that pesticides can be used only as needed rather than as prophylactics. 2. Encourage research on safe application procedures, formulations, and equipment required for more precise delivery and confinement of pesticides to target sites. This should include development of protection for application in the tropics. 3. Establish protocols for registration of new types of pesticides, such as microbial pathogens, hormones, pheromones, hormone-mimicking compounds, and chemosterilants for use in IPM programs. 4. Provide support and develop expeditious procedures for the rapid registration of pesticides for use on minor crops and for minor uses on major crops. 5. Initiate a worldwide study of the hazards of pesticide use and work toward the development of uniform and coordinated regulations for pesticide registration, use, and residue tolerances. Also, the uniform interpretation of toxicological data should be sought. 6. Make a cost/benefit analysis of regulations for pesticide and other pest management tactics, such as resist- ant crop varieties and quarantines. 7. Accelerate research on biologically active molecu- lar structures, such as pyrethroids, naturally occurring growth inhibitors to develop new classes of pesticides. 8. Support research on the phenomenon of acquired resistance to pesticides and procedures for its prevention. PEST MANAGEMENT SYSTEMS Rationale Agricultural scientists have been developing the various components of production of crops and livestock with at best a minimum of interaction between them. The integration of these separate components must usually be accomplished by farmers. Unfortunately, the components are -108-
sometimes incompatible or even counterproductive. Weed control and fertilizer practices may aggravate or reduce insect, disease, and rodent problems, crop rotations or lack of them influence crop protection problems. Some pest management practices may adversely affect production or be incompatible with existing production systems. Thus, there is a great need to develop a total systems approach to management of crop and livestock agroecosystems which include compatible and effective integrated pest management components. Regional systems for detecting, assessing, and predicting pest infestations and pest losses should also receive strong emphasis. Implementation Teams composed of weed scientists, plant pathologists, nematologists, entomologists (and other protection spe- cialists as needed), agronomists, plant breeders, animal scientists, food scientists, and economists should be estab- lished at land grant institutions and USDA units to develop total systems of production of crops and livestock. The crop protection scientists using a systems approach should develop suitable pest management tactics, such as host resistance, cultural practices, and pesticides, and work with production scientists to incorporate these into effective total farm management practices. PEST RESISTANT CROPS AND LIVESTOCK Rationale Crop cultivars (varieties) resistant to pests constitute one of the most economically important and environmentally sound crop protection tools available. Good progress has been made through plant breeding in the control of plant pathogens, and some species of destructive insects. Varieties of potatoes resistant to the late blight pathogen, cereal crops resistant to species of rust fungi, and corn resistant to the southern leaf blight pathogen are familiar examples. Newer varieties of alfalfa have resistance to the alfalfa aphid; several introduced rice cultivars from the International Rice Research Institute (IFRI) in the Philippines are resistant to destructive species of leaf hoppers and stem borers. Weed scientists are following research evidence to determine the possibility of breeding crop varieties resistant to competing weed species. Breedings for pest resistance and tolerance in livestock have shown promise and should be encouraged. The use of pest resistant cultivars may reduce pest populations, and it is compatible with virtually all other control tactics. It is also inexpensive. One major -109-
disadvantage associated with it is the development of pest races or biotypes able to overcome the resistance. Much effort must be expended in the development and use of pest resistant cultivars in integrated pest management. Implementa tion The steps described below are among those necessary for implementing this research. (a) Genetic improvement programs for crops and live- stock must be directed more specifically toward pest re- sistance objectives. (b) A system for coordinating and for enhancing communication between plant resistance programs should be developed on a national and international scale. A national data bank on resistance and general improvement of germplasm resources should be established. (c) Programs for the systematic exploration and char- acterization of useful sources of pest resistance should be strengthened and expanded. (d) Permanent national and/or international systems for maintaining potentially useful germ plasm should be strengthened. (e) Research on new techniques for hybridizing taxonomically diverse plants must be intensified to enhance the use of new sources of plant resistance. BIOLOGICAL CONTROL Rationale Regulation of pest organisms by their natural enemies is of major importance in pest management. Increased funding, improved coordination of personnel and facilities at the exportation, importation-propagation and colonization-evaluation levels, and biological control approaches must be expanded to include pests other than insects and weeds (for example, plant pathogens). Many indigenous pest species maintain low population levels, because they are controlled by natural enemies in the environment. Field experience since the 1940s with the application of synthetic organic insecticides has demonstrated that the natural enemies are often destroyed as well as the pest species. Frequently, the destruction of the natural enemies by synthetic organic insecticides results in the resurgence of destructive populations of the target pest species. The process may also trigger the emergence of a minor pest species into the status of a major pest through destruction of its effective natural control. The preservation and augmentation of naturally occurring biological control agents is essential. The effectiveness -110-
of such agents may be increased through the use of supplementary food sources and kairomones. The mass production and programmed release of natural enemies of pests deserves a special research and development effort. Pathogens have been used effectively in control programs against weeds, insects, and rodents. Microbial agents are ideally suited to integrated pest management programs. They are host-specific and often highly virulent. They cause minimal ecological damage and are highly compatible with other forms of control. Implementation Steps in implementation of this research area include: (a) The national effort to import, produce, distribute, and evaluate natural enemies of pests, including parasites, predators and pathogens of insects, other invertebrates, and weeds should be substantially increased. Also, research on programmed release of beneficial insects and on kairomones should be accelerated. (b) Since biological control of pests is a complex undertaking in view of the ecological and biological knowledge required if it is to be successful, it must be undertaken and supported financially by the government, at all levels, in constrast to direct pest control measures that can be applied by individuals. (c) In addition to an increased effort to import new pathogens, screening of available pathogens and their strains and serotypes against a wide spectrum of pests should be accelerated. INNOVATIVE METHODS Rationale Opportunities for improved integrated pest management have been enhanced by recent identification of several powerful natural and synthetic attractants. The major uses of insect attractants include detection, monitoring for population densities, direct control by poison baits, mass- trapping or inhibition of premating behavior. The potential for using attractants offers opportunities for considerable reduction in the quantities of conventional insecticides employed. Attractants may be useful in concentrating parasites and predators in areas where pests exist. But these too will have their limitation. The feasibility of attracting or repelling nematodes should be explored. Many organic herbicides act as selective plant regulators or synthetic hormones. They are used at concentrations which inhibit weed growth, but have little or no effect on crops. Plant growth regulators may have -111-
potential for stimulating germination of weed propagules (such as seeds, rhizomes, and bulbs) at a time when the physical environment is too harsh for them to survive. Conversely, chemical regulators might be used to prevent germination of weed propagules. More research is needed to elucidate the processes in dormancy of plant propagules. The potential use of plant hormones for modifying crops to reduce their susceptibilities to attacks by pest organisms should also be investigated. Insect growth and development are also regulated by hormones, and insect growth regulators are already in com- mercial use. New and structurally simple molecular models of hormonal pesticides, such as anti-hormones and inhibitors of hormone biosynthesis and metabolism are needed. Additional hormones and neurohormones which regulate life processes unique to pests should be elucidated in order to develop models for interrupting such processes without hazard to higher animals and economic plants. Most serious insect pests reproduce sexually. Geneticists have discovered or invented a number of mech- anisms which may be useful in suppressing important pests. These mechanisms include compound chromosomes, cytoplasmic incompatibility, hybrid sterility, imbalanced sex determin- ing factors, inherited partial sterility, chromosomal trans- locations, sex ratio distortion, dominant lethal mutations, conditional lethal mutations, and meiotic drive. Dominant lethal mutations are used operationally to suppress screwworms, tropical fruit flies, and the pink bollworm. The major difficulty in using genetic techniques to manage insect population lies in the behavioral changes that the pests undergo when they are colonized and mass reared. Experience with a few insects has shown that the field per- formance of mass reared insects is affected by their heredity, nutrition, and physical condition during rearing and release. Implementation The following steps are suggested for implementing the research area. 1. Establish and/or support existing research teams to investigate the identity and role of pheromones, kairomones, allomones, hormones, and other bio-regulatory substances. 2. Support research to determine the usefulness of such regulatory substances for crops and livestock protection. 3. Establish interdisciplinary teams of specialists to develop and demonstrate principles for assuring the behavioral adequacy of mass reared insects used to suppress pest populations by genetic methods or by parasitism. -112-
SELECTED REFERENCES Food and Agriculture Organization (1970) Provisional Indicative World Plan for Agricultural Development. Vol. 1. Rome: United Nations. Glass, Edward H., coordinator (1975) Integrated Pest Management: Rationale, Potential Needs, and Implementation. Entomological Society of America, ESA Special Publication 75-2, August. National Academy of Sciences (in press) Pest Control: An Assessment of Present and Alternative Technologies. 5 volumes. Washington, D.C.: National Academy of Sciences. -113-
CHAPTER 13 MANPOWER EDUCATION AND TRAINING PROGRAMS RECOMMENDATIONS 1: Education Needs. Studies should be instigated on identification and evaluation of U.S. professional and technical education needs to provide adequate human resources for the food system. 2: Fellowship and Research Training Programs in the Basic Sciences of Agriculture. Fellowship and research training programs should be established in the areas of agriculture, food science, and nutrition. EDUCATION NEEDS Rationale Trained manpower is essential if the U.S. is to respond to national and international concerns to help solve the world food problem. The quantity of trained manpower required will increase, and the kind of training necessary will be different than in the past. A manpower training program should be a part of an expanded research investment in food production capacity. Research in agricultural production depends on manpower trained in agriculture, but with heavy emphasis on the biological and physical sciences. There has been a decrease in the training programs sponsored by NSF, the Atomic Energy Commission (AEC), and the National Institutes of Health (NIH) resulting in a decrease in training of basic scientists for research in agriculture. The Commission on Human Resources of the NRC has several on- going studies of training programs for research. Training in biological and physical sciences as well as in agricultural production techniques is required for technicians in agricultural production. While there are several excellent examples of curricular and course changes in agriculture and renewable resources, a systematic review at the national level of the educational resource base and approaches to meet the needs is urgently required. During the past few years, many changes have occurred in agricultural production, processing, and distribution systems in their rural and urban settings, and in their academic and theoretical underpinnings and interactions. A -11 a-
major correlate of these changes is the growth of colleges of agriculture and renewable resources, both in number of students and faculty and in the importance of the findings they generate in resolving many critical problems facing society. These trends are producing an opportunity in agriculture and renewable resource education to anticipate needs and introduce educational program changes which will prepare the kinds of professionals and technicians required for future challenges. Undergraduate enrollment in agriculture in the state universities and land grant colleges more than doubled from 1963 to 1974, an increase of 134 percent. In 1974, enrollment for baccalaureate degree programs in agriculture increased 13.6 percent over 1973. Women in agriculture programs increased 23 percent. Enrollment in technical schools also showed an increase, but enrollment in graduate schools has not increased significantly. Guidelines for educational policy development for the broader academic community in undergraduate and graduate education in agriculture and renewable resources are critical needs. Implementation A study commission should be established to compile an inventory of manpower resources and project needs, and to assess the major issues and priorities for the development of education in agriculture and renewable resources. Competencies must be identified which professional and tech- nical personnel must possess in order to further project national and international goals in food production. Career directed education and training to be considered in this study should be conducted at three levels. 1. Post High School Technical Training This includes vocational and technician training at community and junior colleges. It also includes sub- professional training provided by four-year colleges through the medium of short courses, conferences, seminars, and internships. 2. Academic Education at Degree Granting Institutions This includes education at the baccalaureate level, the science and professional masters level, and the doctoral level. It includes education at the degree level whether or not at recognized schools and colleges of agriculture and renewable resources if such education purports to prepare students for professional careers in these fields. -115-
3. Mid-career Education This includes education for professionals in agriculture and renewable resources and for professionals whose education is in other fields but whose careers are or may be in agriculture and renewable resources. FELLOWSHIP AND RESEARCH TRAINING PROGRAMS IN THE BASIC SCIENCES OF AGRICULTURE Rationale To meet the need for increased research in the basic science areas of agriculture, food science, and nutrition, highly trained research scientists are urgently required. Professionally and technologically trained manpower must increase in the areas of plant physiology, plant pathology, entomology, microbiology, plant and animal genetics, animal nutrition, veterinary medicine, agricultural engineering, food chemistry, nutrition, soil science, and agronomy. This can be most readily accomplished by implementation of a long-term program of support for graduate education in the sciences that are basic to agricultural production. Not only would such programs help the U.S. to better meet its food production and nutrition needs, but it would also help train people from developing countries to better cope with their problems. Implementation A board for international agricultural manpower development should be established to assist in administration of programs to develop training institutions and manpower to meet the present and projected needs for manpower in the U.S. and to assist in developing trained manpower to work abroad. The board should have an adequate budget and authority to award and monitor fellowships and training programs in the agricultural sciences. Fellowships should be made available to U.S. and foreign nationals on a competitive basis. Training grants should be made available to U.S. institutions for both U.S. and foreign nationals. The board should be authorized to foster collaborative relationships between agricultural manpower training institutions in the U.S. and agricultural institutions abroad where scientists are working or have the potential to work on significant programs designed to increase food production. -116-
