On the basis of research done in the Department and literature data, indicesof optimal precipitation and water needs of selected crops (cereals, root plantsand papilionaceae) have been determined. It was found that both insufficient andexcessive precipitation affected yield adversely. It caused the following decreasesin yields: cereals 2-27 and 3-21%, potato 4-45 and 3-30%, sugar beetroot 2-43and 14-19%, fodder beet 16-73 and 8-28%, legumes 5-42 and 21-40%, and papilionaceae3-34%, respectively.Productivity of 1 mm water from precipitation was higher compared withproductivity induced by sprinkling. The calculated index of productivity for waterfrom sprinkling relative to water from precipitation was in the range 40-90%.Sprinkling increased the yield of winter wheat and spring barley by 20%,spring wheat by 25%, potato 47 and 55%, and sugar beet 10-40%. ...
