Dryland farming: Difference between revisions

Dryland farming is an agricultural technique for cultivating land which receives little rainfall. Dryland farming is used in the Great Plains, the Palouse plateau of Eastern Washington, and other arid regions of North America, the Middle East and in other grain growing regions such as the steppes of Eurasia and Argentina. Dryland farming was introduced to the southern Russian Empire by Russian Mennonites under the influence of Johann Cornies, making the region the breadbasket of Russia.^[1] Winter wheat is the typical crop although skilled dryland farmers sometimes grow corn, beans or even watermelons. Successful dryland farming is possible with as little as 9 inches (230 mm) of precipitation a year, but much more successful with 20 inches (510 mm) or more. Native American tribes in the arid SouthWest subsisted for hundreds of years on dryland farming in areas with less than 10 inches (250 mm) of rain.^{[citation needed]}

Dryland farming has evolved as a set of techniques and management practices used by farmers to continually adapt to the presence or lack of moisture in a given crop cycle. In marginal regions, a farmer should be financially able to survive occasional crop failures, perhaps of several years running^{[citation needed]}. Survival as a dryland farmer requires careful husbandry of the moisture available for the crop and aggressive management of expenses in order to minimize losses in poor years.

Key Elements of Dryland Farming

Capturing and Conservation of Available Moisture - In regions such as Eastern Washington state, the average precipitation available to a dryland farm may be as little as 8.5 inches (220 mm). Because of this it must be carefully safeguarded until the crop can utilize it. Techniques for capturing the maximum amount of precipitation include using a summer fallow rotation in which one crop is grown on two seasons' precipitation, leaving standing stubble or crop residue to trap moisture (particularly effective in capturing wind-blown snow), and preventing runoff by terracing fields. "Terracing" is also practiced by farmers on a smaller scale by laying out the direction of furrows to slow water runoff downhill, a practice known as contour plowing. Moisture can be conserved by eliminating weeds, leaving crop residue to shade the soil and by the technique of dust mulching, though dust mulching is rarely used in windy regions due to the severe risk of wind erosion; practice of the technique was a significant factor in the severity of the Dust Bowl storms of the 1930s.

Effective Use of Available Moisture - Once moisture is available for the crop to use, efficient dryland farming requires that it be used as effectively as possible. Seed depth and the time of the seeding are carefully considered in order to place the seed in a location in which it is either currently in sufficient moisture or where it will be when seasonal precipitation falls. Farmers tend to use crop varieties which are drought and heat-stress tolerant, even if they may be lower yielding. This increases the likelihood of a successful crop if the seasonal precipitation ends sooner than normal.

Soil Conservation - The nature of dryland farming makes it particularly susceptible to erosion, especially wind erosion. Some of the techniques for conserving soil moisture, such as dust mulching, are at odds with techniques for conserving topsoil. But since healthy topsoil is absolutely critical to sustainable dryland agriculture, its preservation is generally considered the most important long term goal of a dryland farming operation and conservation wins over moisture retention in those cases. Erosion control techniques such as windbreaks, reduced tillage or no-till, spreading straw on particularly susceptible ground, and strip farming are used to minimize topsoil losses.

Control of Input Costs - Dryland farming is a technique practiced in regions which are inherently marginally suitable for non-irrigated agriculture. Because of this there is an increased risk of crop failures and poor yields which may occur in a dry year regardless of the amount of money or effort spent on the crop by a farmer. Dryland farmers must evaluate the potential yield of a crop constantly throughout the growing season and be prepared to cut inputs to the crop such as fertilizer and weed control if it appears that it is likely to have a poor yield due to insufficient moisture. Conversely, in years in which moisture is in abundance, farmers may increase their input efforts and budgets in order to maximize yields and to help offset poorer harvests.

Notes

See also

• International Center for Agricultural Research in the Dry Areas
• Xeriscaping