Agroengineering technology for the rice irrigation systems to manage drainage flow quality

Under condition of water shortage slow-mineralized drainage water coming from the rice irrigation systems can be used as an additional source of water. Agro-engineering technology on drain-age flow treatment and its reusing for irrigation has been devel-oped and tested by the authors. Agro-engineering technology in-cludes: 1) biosorption facility to remove mineralsalts with the help of specially selected natural mineral sorbents, 2) higher aquatic vegetation to absorb biogenic substances; 3) the developed new sorbent to provide water conditioning. The results of biosorption facility testing carried out at the Sarpin irrigation system in the Republic of Kalmykia showed its high ef-ficiency. A decrease in drainage flow mineralization was observed (from 4.3 to 0.66 g/l), while chlorine decreased from 78 to 28 mg/l, as well as calcium increased from 100 to 124 mg/l. So the efficiency of the suggested technique of drainage flow treatment is rather high which made it possible to use purified drainage flow for irrigation purposes without negative consequences. The appli-cation of the developed technology will get an economic effect by reducing the cost of water supply for the rice irrigation system.