The influence of microbial antagonists on the soil biogenic and the coniferous seedlingssafety in artificial phytocenoses

Strains of microorganisms that have antagonistic and growth-stimulating activity (Pseudomonas sp., Bacillus sp., Bac. subtilis and Trichoderma harzianum) were added to the dark-gray soil of a forest nursery (Pogorelsky EEF) and to conifer seeds (Pinus sylvestris L., Larix sibirica L.). Pre-sowing seed treatments of Trichoderma harzianum, Bacillus sp., and Pseudomonas sp. strains increased Scots pine ground germination in 1.5–1.7 and Siberian larch – in 1.3–5.8 times; improved safety and quality of viable pine seedlings in the 1.4–11.0, larch – in 1.3–3.5 times in the end of the growing season, compared with the control. Morphometric parameters of the pine seedlings increased processing of Pseudomonas sp. and Bacillus subtilis, larch seedlings – Trichoderma harzianum and Bacillus sp. in 1.5–2.0 times (both). The pine and larch seeds bacterization, initially infected by Fusarium, reduced to 1.2–2.5 times the population of phytopathogen, which helped lower the death of coniferous seedlings. The biologically active microbial strains, which were introduced in the nursery soil, have increased and maintained the total number of microorganisms (ETGM) in conifer seedlings during the whole period of vegetation. It has had a positive effect of bacilli treatment (Bacillus sp. and Bac. subtilis) on the dynamics of microbial biomass content, the rate of basal respiration and microbial metabolic coefficient values (qCO2). In general, the introduction of spore bacteria (Bac. subtilis and Bacillus. sp.) and micromycetes (Trichoderma harzianum) populations with coniferous seeds increased the biogenetic and productivity of the nursery soil (MB, enzymatic activity, the ETGM number) to 1.5–3.0 times in comparison with the control and, despite of the high values of specific microbial respiration throughout the growing season, had a positive impact on the restoration of the ecophysiological functioning rule of soil microbial community.