a farming technique involving the retention and accumulation of snow in fields. Snow retention is practiced to increase moisture reserves in the soil and keep overwintering plants warm, including winter crops and perennial grasses. A layer of snow 1 cm thick over 1 hectare of land produces 20-35 tons of water when it melts in the spring. The soil beneath a deep snow cover freezes less, and meltwater therefore easily penetrates the soil. Winter crops receive good protection from freezing by being covered with a layer of snow 25-30 cm deep. In years with dry springs, snow retention promotes uniform sprouting and significantly improves crop yields. For example, it increases grain yields in Kazakhstan by 2-4 quintals per hectare.
Snow retention techniques include forming snow ridges, leaving plant stubble and stalks in the field, planting windbreaks, and arranging artificial barriers in the field. The most common and productive method involves the use of snow ridges. Snow ridges are formed by various types of tractor-driven snowplows and are laid out at right angles to the direction of the prevailing winds or in diagonal-crisscross directions at distances of 5-10 m from each another. Stubble for snow retention may be retained throughout the field or in strips. This method of snow retention is more effective when combined with the use of snow ridges. Plants with high stalks used as windbreaks for snow retention, including corn, sunflower, and mustard, may be sown in fallow fields or in fields already under cultivation (seeSLOT FALLOW and WINDBREAKS). Artificial barriers used in snow retention include panels, dry brushwood, sheaves of straw and reeds, and tree limbs. They are arranged in the field in alternating squares with rows at right angles to the direction of the prevailing winds or to the slope of the field. Forest strips are also a reliable method of snow retention (seeSHELTERBELT FOR FIELDS).
In the USSR, snow retention is practiced in the steppe and forest-steppe zones, especially in regions that do not have thick snow covers, such as the Volga Region, the southern Ukraine, Western Siberia, and northern Kazakhstan. Abroad, snow retention is practiced in the USA, Canada, and Europe.
REFERENCEShul’gin, A. M. Snezhnyi pokrov i ego ispol’zovanie ν sel’skom khoziaistve. Leningrad, 1962.
S. A. VOROB’EV [23–1879–]