As California emerges from a “winter” with average temperatures 4.4°F warmer than the 20th century average and the lowest snowpack in 24 years drought is on the minds of many. While many of us will notice higher water bills, brown lawns, and asking for water when dining out the agriculture industry will continue to bear the brunt of the drought. In 2014 the agriculture industry suffered $2.2 billion in economic losses and 17,000 farmers lost their jobs. We can likely expect more of the same in 2015 as the drought continues, but what, if anything, can farmers do to minimize their losses?
Dry farming is a set of practices that aim to capitalize on using the water stored in the subsoil layer, rather than traditional irrigation, and was practiced long before modern irrigation existed. In areas with long dry seasons and seasonal rainfall, crops such as olives, grapes, figs, apricots, almonds and walnuts were historically farmed without irrigation. Dry farming was widely practiced in California up until the 1970’s, when drip irrigation became the industry standard. Today, dry farming is most notably used in the cultivation of wine grapes in California and abroad – in some regions of Europe it is illegal to irrigate because it is thought to dilute the quality of the wine.
The practice relies on tilling practices that create a “sponge-like environment” in the topsoil. Water from the subsoil layer then rises into the topsoil and a roller is passed over the topsoil sealing in the water and preventing it from escaping through evaporation. Drought resistant varieties are then planted and use the water in the soil to sustain their growth throughout the dry season. The precise timing of the planting and tilling is essential for proper moisture retention.
The potential for dry farming is limited by climate and soil type. A sandy soil will never be suitable for dry farming because any water will quickly drain away. At least 12 inches of rain are needed for proper moisture in soils, excluding much of the Southern portion of the Central Valley. However, in areas that have the appropriate soils and climate, it could prove to be a useful tool for farmers looking to cut costs or make use of land that seemed unsuitable in the current drought.
The lack of irrigation requires less dense planting, because only so much water is available for each plant, and leads to significantly decreased yields, sometimes as little as one-tenth of that of irrigated fields. To some extent, the savings of not using irrigation counteracts the loss in revenue from reduced yields. Irrigation infrastructure can be very expensive to purchase and install, and the cost to pump groundwater will continue to rise as we deplete our reserves. One case study from a vineyard in Sonoma County, CA found that a minimum of 16,000 gallons/acre feet was saved compared to growers who lightly irrigate. Less irrigation can also results in less weeds, reducing the need for expensive herbicides and pest management.
In addition to savings on irrigation, some dry-farmed fruits and vegetables have created a cult-like following for their improved flavor. The improved flavor comes from reduced water content and higher concentrations of sugar and flavor compounds. In recent years, dry-farmed tomatoes have been in high demand from chefs and wholesalers around the country and can provide high economic returns despite low yields.
The economics of dry farmed products are far from certain, however. Though fruit coming from dry farmed orchards and farms tends to be more flavorful and better storing, the commercial fruit industry has invested a substantial amount of time and money in developing standards for large fruit, dependent on the application of irrigation, fertilizers and chemicals. Dry farming is not going to be the answer for large-scale agri-businesses – the yields are too low and crops like strawberries, rice, or lettuce would not survive without irrigation. For smaller growers and unemployed farmhands, however, dry farming could provide some relief in the current agricultural landscape of drought-stricken California.