Yuma County Arizona is only 7% private land; the remaining 93 percent is BLM, Native American, Bureau of Reclamation or State of Arizona. This land is not available for the most part, for private use.
Water for Yuma agriculture is surface diversion from the Colorado River. The 7 farmer operated irrigated districts serving approximately 175,000 acres of cropland, have the oldest water rights on the Colorado River.
The irrigated cropland grows 2 or 3 crops per year, per acre. The winter crops are more than 75 varieties of lettuce, baby greens, cauliflower, broccoli, herbs, root vegetables, kales and numerous other vegetable crops. The produce season starts in August and normally ends in early April.
Summer crops or rotation crops include: Sudan grass for hay and seed, hard red wheat, short and long staple cotton, watermelons, cantaloupes, Honeydew, Alfalfa, Bermuda grass for seed, and other crops that fit the April to August growing window.
Other than the Wellton-Mohawk Irrigation District, all the water is gravity run from the diversion at Imperial Dam on the Colorado River. There is also a lift plant for the Yuma Mesa Irrigation District.
There are approximately 24 coolers located in Yuma to chill the fresh field produce to 46 degrees. The produce is then held in cold rooms until it is loaded on to one of the 1000 or more trucks a day taking vegetables throughout the United States and Canada. The fresh produce usually leaves Yuma within 24 hours of harvest.
Produce is harvested on a daily basis, 7 days per week during the season. In some cases harvest can literally be 24 hours a day, depending on delivery contracts.
Depending on the year, there are 30 to 40 thousand workers daily in the fields. Many of our workers cross the border from Mexico daily. Most produce is touched 3 to 4 times during the growing and harvest process. Yuma agriculture could not be the $5 to 6 billion dollar industry it is without the skilled farm workers we are fortunate to have available.
All of the fields are leveled to pool table flatness. All of the irrigation water and agricultural chemicals applied stay on the fields. There is no runoff or tailwater. The on farm irrigation efficiency of the engineered border irrigation systems is upwards of 75 percent.
Use of sprinklers during the August-September planting season for vegetables assure rapid germination of the seeds, improved microclimates for vegetable transplants and reduce the field temperatures from the 115 degrees air temperature to 85 degrees, allowing the little plants to get off to a good start. Use of sprinklers also saves two-thirds of the irrigation that used to be used during the germination process.
Food Safety is the primary concern for our agricultural industry. Whether people, animals, wind blown dust; litter or contaminated water, there is an extensive protocol to make sure the produce grown and harvested is safe.
From water testing, field fencing, sanitary harvest with workers wearing gloves, aprons, hair and beard nets and sterilizing their work tools, and covering loads leaving the fields for the coolers, our vegetables are protected. The harvest aids used in the fields are sanitized every day. Nothing foreign is allowed in the fields.
Food safety is an added expense of about 5 cents per head which pays for irrigation water testing, fencing and 3rd party audits. The AZ Green Leafy Marketing Agreements determines minimum food safety requirements, but all states are different. The growers started the food safety process, with the government entering the process at a later date.
There are 11 salad plants in Yuma that each process 2 million pounds of lettuce per day for all the bagged products they produce. In the beginning, Iceberg lettuce was the primary variety used now; it is a 50-50 mix of Iceberg and Romaine lettuce.
Yuma grows many varieties of seed crops including onion, artichoke, broccoli, cauliflower, lettuce and various herbs. Since the average rainfall in Yuma is less than 2 inches per year, it is not normally a factor during harvest.
The hard red Durum wheat grown in Yuma is mostly shipped to Italy for pasta production.
Most of the vegetable crops grown in Yuma are grown on north-south rows. The reason is that for multiple crop rows on a bed, the amount of sun each row receives is equal, making a more uniform crop. Vegetables are an indeterminate crop, meaning that the entire crop does not ripen at the same time, so the whole field can be harvested. An example is broccoli. The first cutting is the crowns, multiple heads on a single stem. The next two harvests are the arms, which are bundled with a rubber band.
Melons are planted in February for harvest in May and June. More transplants are being used for melons because of seed costs as well as plant health. With a transplant, the grower knows there is a plant and does not have to worry about seed germination.
Cotton can be planted February 1, depending on weather. The soil temperature needs to be 60 degrees or more. Specially developed shorter season varieties have been used to fit into the vegetable planting timetable.
There is a great deal of technology used in our area. Fields are laser leveled at least once per year to maintain the pool table flatness. Satellites and GPS are routinely used to lay out field rows, during fertilizer applications and mechanical thinning and for tillage. Multiple field operations are combined for fuel, labor and time savings.
Compiled Feb. 2015 by Bobbi Stevenson-McDermott