The dynamics of carbon microbial biomass and the degree of stability of ordinary chernozem under the conditions of transition to processing minimization

The aim of the research was to study the reaction of microbial biomass carbon (Cmb) and the level of stability of ordinary chernozem in the Krasnoyarsk forest-steppe when implementing soil protection processing technologies. The research was carried out on common chernozem of experimental fields belonging to JSC "Dary Malinovky” situated in Sukhobuzimo district of Krasnoyarsk forest-steppe in 2017-2018. The object of the research was chernozem ordinary mid-humic mid-powerful hard loamy soil on red-brown clay. The soil of the experiment was characterized by the content of Sorg - 6.3-6.5 %, neutral reaction of the environment. The content of mobile phosphorus in the soil fluctuated within 295-320 mg/kg, exchange potassium -127-138 mg/kg. In production crops reference sites with a squared total area of 1200 m2, with registration area of 600 m2 were allocated. Within each plot, there were three plots of land-repetitions, each having the area of 200 m2. The sample size equaled n=12. During vegetation season soil samples were taken three times from the layers 0-10 and 10-20 cm using “snake” method. The experiment scheme was represented by the following variants: 1) dump plowing (st); 2) minimum; 3) flat-cut soil plowing. In the season of 2017 the soil of the experiment variants was treated according to the type of bare fallow, and in 2018, spring wheat of Novosibirsk-31 was sown at the stationary plot. During vegetation seasons the dynamics of microbial biomass carbon, basal and substrate-induced respiration and metabolic coefficient were watched. It was found that soil treatment had had a significant impact on the dynamics of microbial biomass carbon, regardless of the nature of mechanical action. The dynamics was a dominant factor determining the transformation of Cmb. The method of tillage did not have a significant unidirectional effect on the degree of soil stability calculated by metabolic coefficient.