Sprinkling(redirected from sprinklings)
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a method of crop irrigation in which water is sprayed over the surface of the soil and on plants. Experiments in sprinkling were conducted in many countries in the 19th century. Sprinkling became industrially important in the early 20th century in Germany (more than 100,000 hectares [ha]), the USA, Italy, and Czechoslovakia. It was first used in Russia (1875) in Saratov Province by the agronomist G. I. Aristov. In 1913 and 1914, on the initiative of A. N. Kostiakov, research on sprinkling was conducted at the Kostychev and Bezenchuk experimental stations. In the USSR the area irrigated by sprinkling (in ha) was 180,000 in 1962, 357,700 in 1964, 760,600 in 1966, and 1,477,000 in 1969. Sprinkling is widespread in Bulgaria, Hungary, Italy, Czechoslovakia, the USA, the Federal Republic of Germany, and the German Democratic Republic.
Sprinkling has a number of advantages over surface watering. It improves conditions of plant growth, since it increases the moisture, not only of the soil but also of the surface air, by lowering their temperature and evaporation losses from the surface of the soil. Sprinkling washes the dust from plants, which strengthens their respiration, assimilation of carbon, growth, and accumulation of organic matter. After sprinkling, the soil structure is less disturbed and postirrigation work may be begun earlier, as a result of which more moisture is conserved in the soil. Sprinkling makes possible the introduction of fertilizers together with the irrigation water. Sprinkling may be done at any time of day and at any irrigation rate, starting with the lowest (30 m3/ha). Sprinkling makes possible the maintenance of optimum soil moisture for plants on lands with complex terrain, as well as on areas of shallow soil situated on strongly water-permeable rock (sand or gravel), on which surface irrigation requires a great deal of planning or entails significant losses of water through seepage. Sprinkling generally does not require shallow conduits and furrows; therefore, the land area is utilized more fully and the operation of farm machinery is more productive. Sometimes this method of irrigation is economically less profitable than surface methods—for example, during irrigation at high watering rates (more than 700 m3/ha) and with frequent waterings.
Sprinkling is used for growing, freshening, feeding, and warming irrigation and in combating weeds. It is widely used in growing vegetable, industrial, fodder, grain, and fruit and berry crops, especially in zones of fluctuating moistening. Sprinkling is most efficient when used against the background of the fall water supply of the soil. During drought years sprinkling yields large crop increases in the nonchernozem zones and even in the north (for example, near Yakutsk). In the Baltic region, sprinkling is used to irrigate pastures and hayfields. Irrigation rates for sprinkling are generally somewhat lower than for surface watering. Watering rates range from 30 to 600 m3/ha (under favorable conditions, up to 800); watering during the growth and development stage should ensure the moistening of soil beds down to root level.
Sprinkling should be conducted in such a way that the water is equally distributed throughout the field, not forming puddles or causing runoff. The occurrence of runoff depends on the physical and water properties of the soil, the size of the spray drops, the intensity of the spray (the layer of rain in mm per unit time), and the nature of its delivery—constant or periodic (with intervals of 1-8 min and more). High-quality sprinkling may be produced if the diameter of the drops does not exceed 1.5-2.0 mm and if the intensity is less than the actual permeability of the soil. For actual conditions, these amounts are generally determined by experiment.
Rivers, ponds, canals, and other basins and channels are used as sources of water for sprinkling. The transmission network (canals and stationary pipelines) and distributing network (open, closed, or combination) feed water to the plot being irrigated and distribute it inside the plot, carrying it to sprinkling machines and installations. The planned arrangement and design of the transmission and distribution networks for sprinkling have the following features: the shape of the plot being irrigated should be close to rectangular, its width should be a multiple of the range of the sprinkling machine, and its length should not be less than 400-600 m; temporary sprinklers and piping are arranged parallel to one another, and the distance between them should be double the length of the wing of the machine or of the spraying radius (taking into account the area of overlap).
REFERENCESPospelov, A. M. Dozhdevanie. Moscow, 1952.
Cherkasov, A. A. Melioratsiia i sel’skokhoziaistvennoe vodosnabzhenie, 4th ed. Moscow, 1958.
Kostiakov, A. N. Osnovy melioratsii, 6th ed. Moscow, 1960.
Lebedev, G. V. Impul’snoe dozhdevanie i vodnyi obmen rastenii. Moscow, 1969.
Z. I. METEL’SKII