The influence of irrigating melioration on the emission of carbon from land geosystems of Selenga Dauria

Gas exchange is one of the most important pro-cesses of a carbon cycle of soil systems. The pur-pose of the study was the investigation of influence of irrigating melioration on the emission of carbon from land geosystems of Selenga Dauria. The tasks of the study were the determination of regu-larities of intensification of breath of alluvial mead-ow soil, comparative assessment of producing car-bonic acid at various ways of its use in agricultural production and identification of possibility of system regulation of CO2 streams. The researches were conducted within the Ivolginsky intermountain hol-low of Selenga Dauria. The breath of alluvial meadow soil was determined by absorbing method once a decade in four geotops of two field experi-ments with two options - with irrigation and without irrigation. Total allocation of CO2 was counted by linear interpolating. It was shown that CO2 emission from the soil in the years of researches considera-bly differed both in time, and in space. It was re-vealed that in agricultural use, plowing emission of CO2 in the atmosphere sharply decreased. It was connected with total destruction of habitat of soil animals and impossibility of their existence. The stimulation of ecological factors by means of irrigat-ing melioration intensified metabolic processes of biotic communities of soil system. As a result, the phytocenosis of irrigated abandoned lands with its loads of mezopedobionts developed by a grass cov-er and branched root system allocated the greatest possible quantity of CO2: 555,5-665,5 g/m2. General losses of carbon from the surface in the form of carbonic acid in warm period from alluvial meadow soil varied from 147.0 to 665.5 g/m2. Maximum car-bon amount emitted with phytocenosis of irrigated abandoned lands. During vegetative period of plants soil breath, irrespective of the way of its use, depended on air temperature, the quantity of drop-ping-out rainfall and artificial overhead irrigation. Carbon dioxide emission from the soil surface was closely and also directly connected with the work of live substance in a bioinert body of the biosphere.