Our study examined the effects of reduced tillage intensity on the size of soil aggregates, their stability, and the composition of microbial communities within them. More than twenty years of reduced tillage in Moškanjci allowed us to evaluate the long-term effects induced by reduced tillage. Two treatments were observed, conventional tillage (CT; moldboard ploughing to 25 cm) and minimum tillage (MT; shallow non-inversion tillage to 10 cm). Composite and undisturbed soil samples from the two treatments (CT and MT) and two depths (0-10 cm and 10-20 cm) were collected in February 2020. Soil aggregates of undisturbed samples were fractionated into 3 size groups (<2 mm, 2-4 mm, and 4-8 mm). Aggregate stability was determined by the wet sieving method. Microbial biomass was estimated by the total extracted soil DNA. The abundance of the archaeal and bacterial 16S rRNA and fungal ITS genes and the denitrifier nosZII gene were determined by qPCR. The shares of selected aggregate size groups were not significantly different between treatments. However, the difference in organic matter content was reflected in aggregate stability, microbial biomass, and abundance of all studied communities which were significantly higher in MT treatment than in CT. No significant difference was observed in the fractions of the same treatment. Moreover, the ratio of microbial communities remained the same, i.e. the most abundant was the bacterial community followed by fungi and Creanarchea. For a more cohesive insight, it would be useful to conduct at least one additional sampling during the vegetation period.
|
