Weather and our food supply

The steep rate of increase in yield of grain crops in the United States since the mid-1950\u27s has resulted in the use of the term explosion in technology. Surplus grains piled up to such proportions after the 1960 · harvest that acreage control appeared. to be in order. But despite substantial reductions in acreages after 1960 the increased output per acre has just about compensated for acreage reductions. During this period of rapid increase in output per acre there has been a growing tendency to believe that technology has reduced the influence of weather on grain production so that we no longer need to fear shortages due to unfavorable weather. There is also a popular belief that acreage control$ fail to achieve the objective of production control, and that public funds are being wasted in storing surplus grains which we don\u27t need. There is increasing evidence, however, that a period of favorable weather interacted with technology to produce our recent high yields, and that perhaps half of the increase in yield per acre since 1950 has been due to a change to more favorable weather for grain crops. These findings have important implications in continued support for research in production technology and in the way in which we look at our surplus stocks of feed and food grains. If a period of favorable weather has been responsible for half of the increase in yields since 19501 then what can we expect if the weather trend reverses itself for a few years? Do we have periodicity in weather, and have we just passed through a run of favorable years that might be followed by a run of unfavorable years? Should we treat our surplus grains as reserves? How does our rate of growth in grain output compare with the needs of a growing world population? And of course I in the background of these questions is one big question -- how much of our recent high yields is really due to weather? To answer these important questions the Center for Agriculture and Economic Development invited outstanding authorities to present their ideas under three main headings: (1) Techniques for Evaluation of Weather Variables in Agricultural Production I (2) Periodicity in Weather Patterns: Implications in Agriculture I and (3) Weather Considerations in Agricultural Policy. The papers have been assembled in the order of their presentation under the general outline above.https://lib.dr.iastate.edu/card_reports/1021/thumbnail.jp

The Effect of Weather and Technology on Corn Yields in the Corn Belt, 1929-62

Excerpts from the report Summary: Recent increases in agricultural output have prompted agricultural researchers to investigate the roles of weather and technology in crop yields. This study assesses the relative effect of each on corn yields in the Corn Belt between 1929 and 1962. Weather indexes were constructed for all States of the Corn Belt and the Corn Belt as a whole. These measures were constructed from corn variety test data, and were used to adjust yield and output series for the influence of weather by a simple deflation process. State indexes were developed by aggregating weather indexes for individual locations. When the weather index is used to deflate the effect of weather on yields, the actual yield series may be adjusted to show the technological yield trend without the effects of weather. Variation in the adjusted yield series is an estimate of the effect of changes in technology. The weather index was also used to facilitate the analysis of the distribution of weather effects and the effect that improved technology has had in reducing fluctuations due to weather

Changing Sources of Farm Output

Excerpts from the report: Except for interruptions during the drought and depression period of the 1930’s, the volume of farm output for human use has trended consistently upward in the United States since 1870. Farm output in 1955, for example, was nearly five times the output 85 years previously. This long-term expansion in the production of food, fiber, and tobacco occurred in response to growth in market demand at home and abroad. Population increased more than fourfold during this period, and a much larger population is now better fed. The volume of exports in the mid-1950’ s was four times that of 1870. In recent years, however, farm output has increased faster than growth in market demand. This tendency toward overproduction of agricultural commodities has depressed farm prices and created major adjustment problems. What were the major sources of this increase in farm output for human use? This discussion is directed chiefly toward an attempt to answer this question. Sources of changes in farm output from the end of World War I to 1955 are emphasized

PRODUCTIVITY CHANGES IN THE FOOD AND FIBER SYSTEM, 1958-74

Measures of output, input, and labor productivity are derived for the food and fiber sector. They are used to analyze changes in output, hours worked, and labor productivity that have occurred in the food and fiber system since 1958. A major result of the analysis is that the reduction in labor at the farm level has apparently not been reflected in either the input or product marketing sectors

Measuring the Effects of Weather on Agricultural Output: Procedures for Constructing Weather Indexes

Excerpts from the report: In this study, the feasibility of constructing weather indexes on a comprehensive scale using a modification of Stallings' approach is investigated. For an empirical appraisal of the methodology of measuring yield variation due to weather, a pilot study of limited scope was undertaken. Eventually, it is hoped that weather indexes for yields and production of individual crops and of all crops can be developed. The indexes would be most useful if developed and kept up to date for farm production regions and the United States. Weather indexes for corn yields and production in Iowa from 1929 to 1960 were constructed using a plot data approach. State indexes were developed by aggregating weather indexes for individual Crop Reporting districts. The weather indexes were used in adjusting for the influence of weather the State and district actual yields per harvested acre and total production of corn. Variation in the adjusted yield series is an estimate of the effect of changes in technology