Influence of plant residue management on microbial properties and water-stable aggregates of two agricultural soils

The objective of our studies was to evaluate the effects of three plant residue management practices on the size and activity of soil microbial community and their contribution to water-stable aggregation in two agricultural soils under continuous spring barley growing. These practices included: straw harvesting, straw incorporation into a depth of 0-20 cm, and straw burning with subsequent incorporation of ash into the depth of 0-20 cm. The straw incorporation treatment, as compared to the two other ones, contributed to an insignificantly higher total amount of water-stable aggregates (0.25-10 mm) in the degraded loam Chernozem (54.1 +/- 4.7%) and the clayey loam Gleyic Fluvisol (62.1 +/- 0.7%). There were differences in the effects of the treatments on size distributions of fractions of water-stable aggregates in both soils. Among the studied treatments, the straw incorporation one led to a significantly (p = 0.01) higher increase in basal respiration only in the degraded loam Chernozem. Compared to the straw incorporation and harvesting treatment, the straw burning one had a significantly (p < 0.01) higher contribution to the accumulation of microbial bio-mass carbon in water-stable aggregates of the degraded loam Chernozem and the clayey loam Gleyic Fluvisol.