Agriculture

More than a hundred and twenty years ago, John Wesley Powell identified the three main potential uses for the arid southwest as irrigated agriculture, pastureland, and timber cultivation.While Powell recognized that desert soils could be productive given cooperative efforts that would provide irrigation water to farmers, he could not have foreseen the future extent of irrigated agriculture.Nor could he have envisioned the crucial role agriculture would play in the economy of the Sonoran Desert and the development of the cities or the conflicts that would develop over urban and agricultural demands for water. Focused on the development of the arid regions and their potential use for non-native peoples, Powell could not have predicted the degree to which impoundment of rivers and streams for irrigated agriculture would change the character of the hydrologic system; or the thousands of acres of land and crucial ecosystems that would be affected due to practices of irrigated agriculture.

Agriculture in U. S. Counties in the Sonoran Desert Region

Note: Information is based on available 1997 U.S. Agricultural Census Data. Some information on crops or farms is not included in the census as listing might infringe of the privacy of certain farmers. Further, it is difficult to discuss possible trends based on a short time span of 10 years. A look at Agricultural Census data for 198, 1992, and 1997 is, however, thought provoking.

Overview

With more than 6 million acres of land in agriculture and sales of over $2.5 billion in 1997, it is apparent that agriculture continues to be an important part of the economy of the portion of the Sonoran Desert that lies in the United States (Table 1). Approximately one fifth (21%) of these agricultural lands are irrigated cropland with the remaining four fifths (79%) largely in use as grazing land with some land used for dairy production or feedlots (Table 2). There is a direct relationship between the percentage of land in either irrigation or grazing land and average farm size.Counties with the highest percentage of grazing land, Pima, Santa Cruz, Pinal, and La Paz, also have the largest average size of farms.Average farm size in Pima County, in which Tucson is located, is nearly 7000 acres.The smallest average farm size (431 acres) is found in Maricopa County, home of the Phoenix metropolitan area.

Crop sales account for the highest proportion of income from total agricultural sales. While information on crop sales is available for only five of the seven U. S. counties (Table 3), these counties account for slightly over $2 billion, or four fifths (79%) of total sales.Of that figure, approximately two thirds (64%) is from sale of crops and one third (36%) from sale of livestock and dairy products.

Acreage planted in a specific crop varies from year to year depending on expected market value, demand, and the status of government subsidies. The major crops for the region, however, based on planted acreage in 1997, are hay-alfalfa and other livestock feed, cotton, vegetables, wheat, orchard crops, barley, and corn respectively (Table 4). The two major crops, hay-alfalfa and cotton account for 58% of the total acreage of 1.2 million acres. Alfalfa, which is planted on nearly one third of the cropland is a water intensive crop as are most vegetable crops. Cotton, one of the three C's for which Arizona was famous "Cows, Copper, and Cotton", is planted on slightly more than a quarter of the land. For a break down of acreage and yield by county, see Table 5 and Table 6.

With perhaps as much as $1.6 billion of 1997 agricultural sales attributable to livestock, the importance of livestock to the economy must be considered. A majority (53%) of farms with livestock raise beef cattle. Poultry farms (15%) and dairies (13%) are the other major livestock farms (Table 7). A look at the actual number and type of livestock produced, however, suggests that sheep are most numerous followed by milk cows, then beef . Sheep accounted for over half (52%) of all livestock in 1997 followed by dairy cows (27%) and beef cows (20%) (Table 8). Nearly three quarters (73%) of total sheep production takes place in Imperial county; while Maricopa county raises 91% of the milk cows and Pinal and Pima counties account for three quarters (74%) of the beef cattle.

Changes:

There has been a general downward trend in the number of farm operations since 1982 (examples from profile). The continuation of this trend is visible in statistics from 1987-1997 (Table 9). During that decade, farm numbers dropped by more than a quarter (-27%). The result was 1,407 fewer farms in 1997 than in 1987. Interestingly, farms size and irrigated acreage increased at the same time farm numbers were declining. Although average farm size fluctuated somewhat during that time period, overall average size increased by 171 acres (8.2%) (Table 10). La Paz county saw the greatest increase (38%) followed by Imperial (30%). Other counties such as Maricopa saw a decline in average farm size (-28%).

In 1997 there were 106,573 more acres under irrigation than in 1987, an increase of 9%. The greatest absolute change in irrigated acreage occurred in Pinal County where 38,000 more acres acres were irrigated in 1997 than in 1987. Imperial, Maricopa, and La Paz increased total irrigated acreage by 24,804, 22,044, and 19,072 respectively (Table 11). The number of acres under irrigation in any one year varies due to a number of factors including type and acres of crops planted, rainfall, and subsidies. California was in the middle of a seven year drought in 1987 which likely affected the amount of land irrigated. In Southern Arizona it is illegal to put new acreage into irrigated production with the exception of certain Native American lands (Kathy Jacobs, personal communication). With increased concern over water availability, competition between urban and agricultural demand for water, and water banking, one might expect irrigated acreage to drop in the future.

In recent years beef cow production has noticeably decreased in parts of the Western United States, especially in those areas dependent upon public lands grazing allotments and in areas where competition for urban development in the form of "ranchettes" is increasing. Data available for five of the seven counties show a dramatic decrease in the number of cows and calves sold between 1987 and 1997. Overall, there was a decrease of nearly one third (-32.3%) with decreases up to nearly half (-47.9%) in some counties and an absolute drop in sales of 150,471 cows or calves in others (Table 12). Despite the fact that sale of cattle is dependent upon local and global market conditions, the steady decline in all counties suggest factors in addition to market value of cattle are in play.

Supplemental Material

• Agriculture - In Nabhan, Gary Paul and Andrew R. Holdsworth. 1998. State of the Sonoran Desert Biome: Uniqueness, Biodiversity, Threats and the Adequacy of Protection in the Sonoran Bioregion. p.34-36.