Where our farm sits, in the Columbia Gorge just a couple of miles east of the Cascades, is considered part of the arid West. This term “arid West” is widely used to refer to a climate in which there is a distinct rainy season, and a distinct dry season during which there is little to no natural precipitation. Most land west of the Rockies is subject to this climate, with wet seasons of varying intensity and duration.
Water is a precious resource — life depends on it. In the Northwest, most of the rainfall occurs during the shoulder seasons (early spring, late fall, winter), when it is cool or cold and plants are not apt to do most of their growing because the day length is short. In order to engage in productive agriculture, many farmers rely on irrigation in order to get moisture to plants during the warm, long-day growing season when they want it. This typically involves tapping a year-round water resource, such as a well or surface water such as a river or pond and spreading large amount of water over the land to encourage plant growth. What is a large amount? In order to provide the conservative estimate of 1″ of precipitation per week, a whopping 27,154 gallons per acre. In the warm season, the needs often triple or quadruple.
That’s a lot of water! And most of it is lost to evaporation, rather than being returned to the rivers or aquifers. While there is a lot of water flowing through our rivers and aquifers, every farmer tapping into these increases pressure and reliance on a resource that is inherently limited. During years of drought, many farmers are not able to get the water they need to cover their fields and suffer great financial losses. The volume of water in rivers decreases over time, and the temperature of the water rises, leading to the demise of many important species of fish, frogs, and the other wildlife that depend on them for food. It is, in short, not very sustainable — not just in the sense of the feel-good buzz-word, but in the sense that we won’t be able to keep this up for very long before we run out of water altogether, and desertification starts to set in.
Technologies are being developed to help reduce the impact of agriculture on our water resources. Drip tape and other prolonged, low-volume irrigation emitters have been a huge step forward in efficiency of water use. This is used primarily in the fresh vegetable industry, due to the fact that the water is targeted specifically to the roots of individual plants — grass growers and many large-scale field crops still depend on inefficient overhead sprinklers.
The states of Washington and Oregon know that water is a declining and precious resource, and so they have long ago instituted a system of “water rights”, by which the type and amount of water used by an owners or business is attached to that property in perpetuity, and they cannot exceed their limits for use. Older properties that have been in agricultural hands for many generations often have very generous water rights — more water, perhaps, than they ought to be using. Properties that have fallen out of farm use or were established for agriculture later in time often have extremely restrictive water rights — ones that make farming there a very difficult endeavor. The “farmability” of a property is often associated directly with its rights to draw on ground and surface water for irrigation.
Dry-farming offers us an alternative. This means farming without artificial irrigation, and maximizing the utilization and retention of the soil moisture available during the wet season in order to help plants make it through the dry season. Rather than struggle against the natural state of affairs, we work with it. For late-maturing crops, we grow varieties that root deeply and are able to follow the retreating level of moisture down through the soil into the dry season. Early-maturing crops that are able to tolerate cool weather and produce a harvest before the summer drought sets in also work well in this system. Our pastures are filled with perennial grass species that are adapted to our climate, which mature early but retain nutritional value and palatability long after the plant has gone dormant for the season, allowing us to ‘stockpile’ grass in small sections that we move through daily or weekly and graze the animals all summer long without the negative effects of over-grazing key species often caused by free-range grazing on dry land.
If practiced improperly, dry-farming can cause environmental devastation just as easily as irrigated farming can. This is why we couple our dry-farming with a minimal-to-no-till system. One of the most well-known books in dry-farming was published in the 1900s by Johnathan A. Widtsoe, called Dry Farming: A System of Agriculture for Countries under Low Rainfall. While this book is an invaluable resource about the concepts of dry-farming and we highly recommend reading it, one important area in which we part from his advice is tillage (cultivation). Jonathan stresses that the only way to lock the appropriate amount of moisture into the soil to prevent evaporation and keep weeds from depleting the residual moisture is tillage, tillage, tillage. Well, we disagree! Tillage, especially in very dry soil, makes land like ours especially susceptible to erosion and runoff, mobilization of important nutrients, and disturbance of the structure of our topsoil and important microbial life. It could blow away all summer as dust in our famed Columbia Gorge wind. Instead, we focus on the use of mulches as our primary tool for retaining moisture and keeping weed pressure under control in our crops. We have utilized both straw and landscape cloth to help with this. We rely on this lack of tillage to help develop our soil structure and reduce compaction so that plants roots can easily dive deep into the subsoil to find moisture even during the hottest, driest parts of the season.
There are some specific criteria that land must meet to make the most of dry-farming, and there are some conditions under which it simply cannot be a success. The first and most important thing is soil type. Clay soils, while typically regarded as sloggy and undesirable for conventional agriculture, are actually ideal for dry-farming! Why is that? Clay absorbs and retains moisture for much longer than sand or loam type soils. A clay-loam is an ideal balance of nutrition, organic matter, and the right absorbency. This soil must be well-drained enough that water does not constantly pool on the surface, but have a large holding capacity that allows moisture to build up in the sub-soil during the wet season and not drain away to aquifers or rivers before your plants can access it. Soils that have veins of gravel or sand are not ideal for this reason — they will shuttle the water away too quickly.
The other condition is that it is important that it does not rain during the dry season. I know that sounds a bit silly and counter-intuitive, but a summer storm that interrupts a drought can cause your sub-soil moisture to evaporate. Your topsoil acts like a wick to the subsoil — in the wet season, is draws water down into storage. It is then important that dry conditions be maintained on the surface of the soil (either through cultivation or mulch, and we prefer mulch), which creates a barrier between the hot, dry summer air and the wet subsoil, preventing it from evaporating away. If the topsoil or mulch becomes moist during the hot dry season, water from the subsoil can ‘wick’ to the surface and be gone very quickly.
Without irrigation, dry-farming offers about 1/3 to 1/4 of the yields of a typical irrigated acre in terms of weight. Most people look at and aren’t very encouraged. However, the high labor and power costs associated with irrigating are lower in a dry-farmed system as well. Commercial-scale irrigation is not only impractical but also illegal on many properties in the arid West. Rather than forsake these places (like our property) and turn them into vacation homes or timberland intended for clear-cutting and the devastation that follows, dry farming can help keep these places in productive agricultural use and preserve and build vegetative cover and native species of plants and animals. Crops and forages grown on dry-farmed land offer a much higher concentration of nutrients and flavors than those grown under a traditionally irrigated system — and the same goes for animals that eat extra-nutritious dry-farmed forages.
Have you ever heard that stressed, droughty grapes make the best-tasting wine? This is true of many other species of plants as well. You’ll know the minute you’ve taken a bite of a small, but poppy-red and incredibly sweet dry-farmed tomato. When you buy dry-farmed products, you’re not buying a bunch of extra water pumped into a crop to make it weigh more. Dry conditions cause plants to concentrate their flavors, sugars, proteins, vitamins, and minerals into a smaller package that will wow the taste buds and help build the health of any human or animal consuming it. Many chefs and nutritionists will tout the value of dry-farmed foods, and meats from animals raised on them.
While a there is still a percentage of our crops at Horseradish Ranch and Blue Moon Stead that depend on irrigation, dry-farming remains the focus of our operation. With each year we hope to increase our skills and abilities in this type of farming and help others become successful with it in the future as well. We believe there is an inherent value in food grown this way, and in a system that can be developed to feed people and improve land in the long, long run — long after our ability to depend on commercial irrigation dries up in our region.