Technology of use of mineralized water for forage crops irrigation

Abstract

Relevance. The Republic of Kalmykia is located in the еuropean part of the arid belt of the Russian Federation, in which there is the water demand for social and industrial needs, for land reclamation development, for pasture lands watering and irrigated agriculture. The natural hydrographic network is very poorly developed. Local surface flood runoff is accumulated in numerous small water bodies (lakes, ponds and reservoirs). The qualitative composition of these waters is distinguished by a relatively high salt content (the degree of mineralization ranges from 2 to 6 g/l). The useful water runoff, depending on the average moisture content per year, varies from 0.5 to 30 million m3, which makes it possible to organize small areas of irrigation of the oasis (focal) type based on a database of water bodies. The largest volumes of drainage and waste water are formed in the Sarpinskaya, Chernozemelskaya and Pravo-Egorlykskaya irrigation and drainage systems, which makes it possible to reuse them. To prevent negative processes developing on the soils of the arid area when crops are irrigated with highly saline water, it is important to develop a technology for their usage.Methods. Long-term field studies on the development of an environmentally safe technology for growing fodder crops under irrigation with mineralized waters were carried out on zonal light-chestnut solonetz, light and medium loamy and brown semiarid soils. The objects of the research were agrocenoses of perennial (Medicago sativa L., Elytrigia elongata (Host) Nevski) and annual fodder crops (Amaranthus paniculatus, Sorghum sudanense, Sorghum saccharatum (L.) Pers.). The irrigation regime was maintained at a level not lower than the limit of water movement in the form of capillary currents (75–80% HB).Results. Agrotechnological measures have been developed to create optimal environmental conditions for growing fodder crops with highly saline water irrigation, including: the right choice of site, the selection of salt-resistant crops and the development of reclamation-forage crop rotations, the parameters of the water and nutrient regimes of the soil, ensuring hay yields at the level of 12–15 t/ha.