California farmers used modern irrigation methods, such as sprinkler and drip, to introduce advances in the use of chemical fertilizers. More recently, computerization has contributed to the more precise management of irrigation. While the emphasis on irrigation is one distinctive feature in California agriculture, perhaps an even more important feature that distinguishes this state is the selection of crops. California agriculture is the leading producer of fruits, nuts, vegetables, and flowers in the nation—and, for many fruit and nut crops, in the world. The land share of these crops has grown steadily over time. The nature of these crops, which are less important in much of the heartland of the United States, means that a great deal of the technological development in California has more in common with Florida, parts of the southern hemisphere, and regions of the Middle East , than with Illinois and Iowa. The evolution of agricultural technology in California was strongly influenced by technological innovations and other events that originated in non-agricultural sectors of the economy. During the late nineteenth and early twentieth centuries, much of the Central Valley consisted predominantly of grain-producing areas. Grains were essential for feeding the local population and their draft animals, which provided the main source of energy for transportation and farming. Early California exported grain mostly by boat, but the introduction of the railroad provided a cheaper alternative. Dried or preserved fruits and vegetables were also shipped,maceta redonda since logistical constraints prevented the export of products with a relatively short shelf life.
During the second half of the twentieth century, with the introduction of the federal highway system and great improvements in truck transportation, California began shifting toward the export of fresh fruits and vegetables. The past 10 or 20 years have seen increased airplane transportation to export high value-added, tree-ripened fruits from California to markets in Pacific Rim countries as well as along the East Coast—another step in the continuing process of supply response to improved transportation technology that began a century earlier .Subtropical crops and vegetables produced in California have had extensive technological exchange with other regions where weather and crops are similar. In the nineteenth century and early twentieth century, a significant transfer of technology came from southern Europe and Asia to California, embodied in the immigrants from Italy, Germany, France, Armenia, and Odessa near the Black Sea who settled in the San Joaquin Valley, near the Russian River, and in other areas of California. These immigrants brought crop varieties and cultivation practices from their original countries and established the foundation for many fruit and vegetable industries in California. Traffic in ideas and technology has been on a two-way street, however. Early on, for example, the wine industry in California was essentially an importer of knowledge from France and Italy. However, as the University of California developed its significant research capacities, the state evolved from being an importer to an equal trader and even exporter of agricultural knowledge. California developed its own varieties of wine grapes, stone fruits, nuts, and citrus, and some California grape varieties were even sent to France to cope with a plethora of problems in the wine industry there.
While traditionally in many Mediterranean countries almond and other nut trees were grown mostly as single trees, without much cultivation, California researchers in the Experiment Station made a strong effort to adapt many nut varieties to California conditions and to increase their intensity of production. California has become the leading state worldwide for varieties as well as production methods in almonds, walnuts, and pistachios. Additionally, realizing the relatively small markets for many fruits and vegetables, California farmers have continually sought to produce new specialty crops and develop markets for them. Transfers of technologies between California and regions with similar crops and growing conditions have continued. Drip irrigation and the production system developed around it came from Israel. Some South African entrepreneurs and Australian companies have played a major role in technology transfer.5 California has been a major beneficiary of the Bi-National Agricultural Research and Development program with Israel. This research program, with an endowment of about $200 million, has allocated a large share of its U.S. funds to California research institutes. Much of the expected economic benefit from this program has accrued to growers in the form of improved irrigation and drainage practices, the use of computerized systems in cotton production, introduction of solarization for pest control, and so on. California growers constantly benefit from varieties being developed in other countries, including high-value flower and vegetable crops from the Netherlands and, especially, the range of fruits and vegetables from Asia. The international spillovers of genetic material are not confined to exotic species, however. For instance, Pardey, Alston, Christian, and Fan showed that California has been a major beneficiary of new wheat and rice varieties developed by the International Agricultural Research Centers of the Consultative Group on International Agricultural Research . The new higher-yielding wheat varieties developed by the International Maize and Wheat Improvement Center in Mexico, incorporating semi-dwarfing genes and rust resistance, were designed for developing countries but turned out to be especially suitable for use either directly, or as parental lines, in California and Australia. Similarly, the improved rice varieties from the International Rice Research Institute in the Philippines have been relatively well suited for adaptation and adoption in California.
Essentially all of California’s rice has some IRRI ancestors.Asian-Americans have played a dominant role in California’s high-value crops, especially along the coast. While California has been a significant importer of crops and varieties, exports of crops and genetic material from California have outweighed the imports significantly. In the future, we may expect much more emphasis on the development of crops and varieties to meet Pacific Rim demands. California has by far the world’s strongest research establishment in subtropical agriculture, exporting knowledge that was crucial in the development of cotton and subtropical farming in Australia, Israel, and other countries.6 In recent years a significant transfer of agricultural technology has taken place, including processing as well as production technologies, from Northern California to Latin America, especially Chile and Mexico. NAFTA may well encourage a gradual integration of farming in California and certain regions in Mexico that produce high value crops. Finally, there has been a steady technology exchange between California and Florida, which are unique in the nation for their subtropical crops such as citrus.7Without irrigation, much of California would be a dry and nonproductive land. With irrigation, however, the Central Valley has become the most agriculturally productive valley in the world. Combined with the soils, climate, and a long growing season, water availability has brought high yields per acre for a multitude of crops. Traditional irrigation in California was based on gravity and consisted of either flooding the fields or using furrow delivery. These methods were often technically inefficient, since a significant portion of applied water was not consumed by the crop but ended up as deep percolation, runoff, or evaporated water. Modern technology has increased irrigation efficiency significantly. Sprinkler and drip irrigation can increase yields and save water, especially in areas with sandy soils where deep percolation is significant, and with uneven soil topography where problems of runoff are severe. The problem with percolation is especially serious in some areas of the Central Valley where there is an impenetrable soil layer close to the surface, which results in water logging problems. In these cases, adoption of modern irrigation methods can avoid or slow these problems. While modern irrigation tends to increase revenue by increasing productivity, it can entail higher capital costs. Producers must balance gains against costs. Studies suggest that adoption of the new methods is most appropriate in areas with high-value crops, high prices of water, and farming conditions that make them attractive. Modern technologies are not appropriate for every location,macetas redondas grandes as for example in areas with low-value crops and heavy or poorly drained soils. At present, only 25 percent of California farmland is irrigated by sprinkler, and the share of drip is 10 percent or less. Table 4 presents information about adoption of irrigation technology over time in California.While sprinklers and drip delivery systems can cope with uneven terrain, much of California’s irrigated agriculture is irrigated by flood or ditch-and furrow methods fed by gravity, especially field crops . An important element in the development of irrigation technology for these crops, and improvement in the control of water, has been the use of improved grading techniques, especially laser leveling technology. Much Central Valley farmland has been leveled over the years, making flood and ditch-and-furrow irrigation efficient and cost-effective.Irrigated agriculture in California benefited from developments outside agriculture and from the importation of technologies from outside the United States. The ability to drill deep wells and convey water under high pressure, activities important to the use of sprinkler systems, came in large part from knowledge acquired in the oil industry; learning how to pump and transfer liquid in the oil business led to developments later found to be profitable when applied to water.While sprinkler irrigation was introduced prior to World War II, the sprinkler manufacturing industry went through a period of rapid expansion after the war. The early sprinkler systems consisted of iron pipes that connected sprinklers to the main water line.
The early post-war years also saw an excess U.S. production capacity for aluminum; since then, there has been a rapid increase in the share of irrigation systems that use lighter aluminum pipes, which have enabled the introduction of movable sprinkler systems at lower cost, an attractive alternative for some field crops, including cotton. Sprinkler systems were largely promoted by manufacturers and dealers from which farmers rented equipment in early years. As they became more knowledgeable about sprinkler irrigation, farmers rented equipment less frequently and began to purchase it outright.Since different crops have different requirements, and the profitability of investment in equipment may be different, various types of sprinkler systems have evolved; this evolution also reflects new opportunities with respect to materials and equipment. Many field crops still use the removable sprinkler system. In these cases, farms do not spend much money on equipment; the pipes are simply moved from field to field, which restricts the frequency of irrigation. Higher value crops use permanent sprinkler systems, which allow quicker response to changes in weather and also permit longer irrigation cycles with lower volumes, which increases water use efficiency. In some cases, sprinkler systems are also used for frost protection. With the introduction of plastic, there has been a demand for sprinkler systems relying on plastic pipes and meters, which may be less expensive in terms of cost and easier to move, but may require more frequent replacement.The most significant adaptation of the sprinkler system was the introduction of center pivot irrigation in the 1970s. This system revolutionized agriculture in the Midwest and increased the irrigated acres in the United States by several million acres, but it has not had a significant impact on California agriculture. Center pivot irrigation is most appropriate for crops such as corn, and is most efficient when the same machinery is used for both pumping of groundwater and irrigation. This system also requires production in continuous plots of quarter sections . While center pivot might have been appropriate for crops such as alfalfa and cotton in California, reliance on groundwater for these crops is not very common, so a combination of pumping and irrigation is not likely.Drip irrigation is another form of modern irrigation that has had significant impact on California agriculture. Introduced into California in the late 1960s, drip was initially exported from Israel. This system requires a high up-front investment; therefore, it is primarily adopted for high-value crops in situations of water scarcity, and in locations where it is especially favorable. The first significant adoption of drip was in the avocado orchards of the San Diego area, where it enabled expansion to steeper hills in both San Diego and Ventura Counties. Similarly, the use of drip enabled expansion of grape production to the hills of Monterey County and throughout the Central Valley. Drip systems can be very complex.