Davis, Calif. — Back in the days when gold was discovered in California, the area was considered anything but a land flowing with milk and honey. In 1855, for instance, a visitor confidently predicted that ''California's valleys will afford a sufficient supply of breadstuffs to support sparse settlements, but the average or general surface of the country is incapable of sustaining dense populations.''
Today, California is the salad bowl of the United States. It produces nearly half of the nation's fruits, nuts, and vegetables.
What the 19th-century observer failed to anticipate was the effect of a process that began at about that time: the application of scientific methods to agriculture. This process transformed the very fabric of US society. And nowhere has its impact been as pronounced as in California.
Driven by the need to adapt to the state's dramatically diverse climatic, soil, and water conditions - and inspired by the flair for innovation for which California's inhabitants are noted - growers there have frequently been in the forefront of agricultural change.
Recently, a number of the architects of this revolution gathered at the University of California, Davis, (UCD) here to take stock of what they helped create. And they offered some tantalizing glimpses into the future of US agriculture. The occasion was the 75th anniversary of the campus, one of the nation's foremost agricultural institutions.
The raw statistics are remarkable enough. In the past 50 years US farm output has increased nearly 21/2 times. During the same period, the number of farm laborers has plummeted to one-fifth of previous levels, use of machines has tripled, and the application of chemicals has risen by 25 times.
Chester O. McCorkle, professor of agricultural economics at Davis, totaled up some of the pluses and the minuses of this transformation:
On the positive side of the balance, he lists:
* The creation of an unprecedented abundance of food and fiber at low prices, which has helped feed a substantial portion of the world's people.
* Freeing the labor needed to build the nation's industrial might.
The negative side effects he cites include:
* Serious soil erosion and the depletion of underground water reservoirs.
* Periods of overproduction, increased farm sizes, farmers' heavy dependence on credit, and the decline of the political power of the farming community.
* Serious health and environmental pollution problems caused primarily by the use of pesticides.
Today's agricultural scientists are directing their efforts toward preventing or minimizing many of these problems, Dr. McCorkle claims.
''Today the criteria for selecting agricultural production and processing practices and assessing new technological developments are being broadened. We have come to believe that what promises to be the best for the producer in the short run may not necessarily be best in the longer run for either the producer or society,'' he says. The new criteria he refers to are energy efficiency, acceptable long-run environmental impact, acceptable health and safety risks, and acceptable social cost.
The direction of current agricultural research is critically important: Scientists involved report that the new tools of genetic engineering and computer technology are setting the stage for a second agricultural revolution equally or more profound than that begun a century ago.
''It is very likely that we will witness changes in the next 25 years as dramatic as they have been in the past 75,'' asserts Charles E. Hess, dean of the Davis College of Agricultural Science.
According to James M. Lyons, assistant director of the Davis Agricultural Experiment Station, genetic engineering has already made plant breeding along traditional lines quicker and more effective.
Traditional plant breeding involves screening hundreds of plants for desirable traits such as tolerance of heat or resistance to certain pests. If individual plants with the desired characteristics are found, they are bred into existing strains. For instance, the development in the 1920s of iceberg lettuce, which thrives in the hot, foggy conditions of the Salinas Valley, transformed the area into the major lettuce-producing region in the nation. Despite such successes, these techniques have been limited by the characteristics of specific plant species.
Now, recent discoveries in genetics make it possible to transfer important traits from different species, even entirely different types of organisms. For instance, plant geneticists have identified a dwarfing gene in peach trees. This makes it possible to make peach trees grow as bushes. These produce more than twice the fruit per acre and can be harvested mechanically, Dr. Lyons reports. This same approach should work with nectarines, almonds, and walnuts as well.
And ''the search is on to develop bush-type melons,'' the scientist says.
Within the last few months, scientists have reported the first success in transferring a bacterial gene to a whole plant and having it work. This has caused considerable excitement because bacteria have traits such as resistance to common herbicides and tolerance to extreme temperatures, salt, drought, and high levels of some minerals. These are characteristics that scientists would like to transfer to commercial crop species. Z0213R F ZSALAD1 second ''This will happen within five years,'' Lyons predicts.
''As plant scientists labored to develop a viable crop-production system over the past 75 years, they logically focused their attention on production problems and yield increases. As we look to the future, more of their effort will be directed toward developing traits . . . which will lead toward more efficient use of resources, greater environmental protection, and improved-quality plant products,'' he says.
Although concern over possible side effects of artificially altering life-forms has died down in the last few years, there are some groups that view this work with concern. Recently, a number of environmental groups sued the National Institutes of Health, charging it with gross negligence for approving field experiments of genetically altered life-forms. The experiment that triggered the suit was proposed by researchers at the University of California, Berkeley. They wanted to spray a small field with an altered form of bacteria that normally live on plants. The bacteria have been changed so they do not produce a protein that helps ice form. The goal was to see if the bacteria will reduce frost damage.
Meanwhile, parallel genetic efforts are under way in animal breeding. In this area, the dairy industry has taken the lead. Because of improved diets and breeding programs, the nation's milk supply now comes from 11 million instead of 28 million cows, says animal scientist Robert W. Touchberry. The doubling in average milk production has come through intense selection of bulls that give the most productive offspring. Due to widespread use of artificial insemination, the entire dairy herd comes from less than 100 bulls.
In the last year, animal scientists have successfully cloned calves. ''This makes it possible to select the most productive cows as well as bulls,'' Dr. Touchberry reports, making it possible that the nation's dairy herd may ultimately be descended from only 100 cows as well. While this could further increase milk production, it also represents an increased risk of the widespread propagation of unrecognized genetic problems.
Similar techniques are spreading to beef, pigs, and other livestock as well. Such modern breeding methods, combined with factory farming techniques, have managed to keep the cost of meat much lower than it would have been otherwise. However, animal rights advocates adamantly opposed the treatment of animals as food machines. They argue that factory farming is cruel to the animals and dehumanizing to the farmers. While skeptical of many of the animal advocates' claims - ''Just because you would be unhappy in a cage, doesn't mean a chicken is,'' responds Dean Hess - animal researchers have begun to take some of these issues seriously. For instance, Davis recently hosted a conference on stress in farm animals.
In the farmers' unrelenting battle against pests, genetic engineering and the computer will play an important role, argues Davis toxicologist Donald G. Crosby. Despite mankind's best efforts, pests of all types still manage to destroy about 50 percent of the harvest worldwide each year. In the recent past, farmers have relied extensively on chemical pesticides. But these have had bad side effects on the environment and human health and the pest species have repeatedly become immune to their effects. Finally, with recent increases in cost, the farmer's price tag for conducting chemical warfare on pests now equals the value of the produce saved.
The coming thing in pest control, Dr. Crosby says, is an approach called integrated pest management (IPM). This substitutes detailed knowledge about pests' natures and habits in place of indiscriminate use of chemical poisons. An example of a recent IPM success involves almond trees. For years these have required heavy doses of chemical pesticides. But pesticide use has been drastically reduced through a combination of methods: cleanup of unharvested nuts; earlier harvesting; use of natural predators to fight mites; and applications of pesticides only when the pest species begin showing up in baited traps.
''The result is that both the net cost and the proportion of reject nuts have typically been cut in half, and often no pesticides are required,'' Crosby reports.
The next 25 years ''should see the demise of the eradication mentality - the notion that 'the only good bug is a dead bug' - and the acceptance by man that he and his crop plants and domestic animals are parts of complex ecosystems governed by basic ecological principles. Chemical pesticides will fade,'' the toxicologist predicts.
Because ecosystems are so complex, determining the best methods to combat pests requires considerable computer power. But computers will be making an impact in a number of other ways as well. More than 65,000 of the nation's farms are already using computers. And the applications are growing. One company has perfected a computerized device that can cut down the amount of fuel used in tilling by selecting the best gear and engine speed for a tractor. Another agricultural entrepreneur has perfected a computer system that not only weighs tomatoes, but determines their quality.
As computer technology spreads, there are likely to be fewer and fewer unskilled jobs on the farm, Dr. McCorkle says. The jobs of agricultural workers will increasingly resemble those of urban laborers. Robots may be used to automate some food-processing plants. But the economist argues that the lack of precisely controlled conditions in the field means that ''the human operator will remain as the key controller,'' and computerized machines will be designed to aid rather than replace workers.
Further, computer systems, when combined with electronic sensors that can provide instant information on soil moisture, plant growth and health, and other important conditions should allow farmers to use fertilizer and water more efficiently. This would not only benefit the farmer, but also reduce the adverse environmental effects and water consumption of agriculture.
In short, the agricultural scientists foresee a brave new world on the nation's farms and they hope that their efforts will make it not only brave, but better as well.