Dry farming is an agricultural approach focused on producing crops without supplemental irrigation in regions that naturally receive low levels of annual rainfall, typically less than 20 inches. This method maximizes the use and retention of natural precipitation stored in the soil. The question of who invented dry farming is complex because the techniques are not the product of a single mind or moment in history. Instead, the practice evolved from millennia of traditional, localized moisture conservation efforts before being codified into a formal, scientific system in the late 19th and early 20th centuries.
What Defines Dry Farming and Its Principles
The core of dry farming rests on principles designed to conserve every available drop of moisture in the soil profile. The primary goal is to maximize infiltration and minimize water loss from evaporation and competitive plant growth. Successful dry farmers select sites with deep soil, often clay loam, because its structure allows for better water penetration and storage down to a depth of eight feet or more.
A crucial technique involves fallowing, where land is deliberately left unplanted for an entire season to accumulate moisture from two years of rainfall for a single crop. This fallow period is paired with specific tillage practices to manage the soil surface. One historically central method involved shallow cultivation to create a fine layer of loose soil, often called a “dust mulch,” which was believed to prevent water from rising to the surface and evaporating.
Weed control is the most important factor, as unwanted plants consume significant amounts of soil moisture needed by the main crop. Farmers must select specific crop varieties that are either drought-resistant, meaning they slow growth during dry periods, or drought-evasive, meaning they mature quickly before the driest part of the season. Planting density is often reduced by using wider row spacing, which provides a larger volume of stored water for each individual plant.
Historical Precursors to Moisture Conservation
The concepts underlying dry farming predate modern agricultural science by thousands of years, arising independently in arid regions worldwide where survival depended on water stewardship. In the Near East, farming communities were established where annual rainfall exceeded the 250-millimeter threshold necessary to sustain cereal crops without irrigation. Ancient Greek and Roman agricultural texts also describe practices used in the Mediterranean that focused on soil moisture retention for crops like olives and grapes.
In North America, Indigenous groups perfected techniques for growing staple crops like corn, beans, and squash in dry conditions. The Hopi people of the Colorado Plateau, for instance, developed a system sustained for over 3,000 years with only six to ten inches of annual precipitation. Their methods included planting seeds extremely deep, sometimes a foot or more, to place them directly into the permanent moisture layer of the subsoil.
Hopi farmers also practiced cluster planting and utilized exceptionally wide spacing, often six feet between corn clumps, to limit competition for the scarce water supply. These traditional practices represented a profound, localized knowledge of soil, climate, and seed adaptation passed down across generations, laying the practical groundwork for later scientific codification.
The Modern Pioneers of Dry Farming
The transition from traditional practice to a formalized, marketable system occurred in the American West during the late 19th century, driven by the push to settle the Great Plains and Intermountain regions. Two key figures systematized and popularized the practice, moving it from a localized technique to a widely promoted agricultural system.
Hardy Webster Campbell, a homesteader in the Dakota Territory, was the most prominent early popularizer, starting his experiments after crop failures in the 1880s. Campbell developed the “Campbell System” or “Scientific Soil Culture,” which relied heavily on specific tillage methods. He advocated for deep plowing, alternating summer fallow, and the use of the subsurface packer, a device he invented to compress the subsoil and improve moisture retention. Campbell promoted his system through demonstration farms and publications like the Soil Culture Manual (1902), often supported by railroad companies eager to attract settlers.
John A. Widtsoe provided the rigorous scientific validation that established dry farming as a legitimate academic discipline. As the Director of the Utah Agricultural Experiment Station and later President of the Utah Agricultural College, Widtsoe conducted extensive research on water conservation in arid climates. His influential 1911 text, Dry-Farming: A System of Agriculture for Countries Under a Low Rainfall, synthesized the principles of water storage, soil chemistry, and crop physiology. Widtsoe’s work shifted the focus from Campbell’s reliance on the dust mulch theory to a broader, scientifically sound understanding of moisture management, solidifying modern dry farming principles.