EFFECT OF BACTERIAL POLYSACCHARIDES ON THE STRUCTURAL AND AGGREGATIVE STATE OF MEADOW CHERNOZEM I. M. Malinovska, N. I. Dragan

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ISSN 1995-5537

«Біотехнологія» journal V. 5, No. 6, 2012
Р. 95-100, Bibliography 12, Ukrainian.
Universal Decimal classification: 579.22: 579.243.6: 631.461.61

EFFECT OF BACTERIAL POLYSACCHARIDES ON THE STRUCTURAL AND AGGREGATIVE STATE OF MEADOW CHERNOZEM

I. M. Malinovska, N. I. Dragan

National Scientific Centre “Institute of Agriculture of National Academy of Agriculture Sciences of Ukraine”, Kyiv

The ability of bacterial polysaccharides of different chemical composition, structure and systematic position of producers to improve the structural and aggregative state of meadow chernozem was investigated. It was found that the most effective of agronomically valuable aggregates increases exopolysaccharide Bacillus mucilaginosus C-3 in the maximum concentration of the tested one — 0.016%. The number of units in size 3–5 mm increases at this concentration of polysaccharide to 22.6%, in size 2–3 mm — to 11.1%, 1–2 mm — to 5.12%. When polysaccharide concentration decreases, the effectiveness of its action is significantly reduced.

All the tested concentrations of polysaccharide B. mucilaginosus increased the content of water-stable aggregates in the soil: the native polysaccharide in concentration of 0.016% — 51.4%, 0.008% — 17.6, 0.002% — 25.4, degraded polysaccharide in a concentration of 0.016% — at 6.33%. Polysaccharides of other investigated microorganisms Rhizobium phaseoli 8 and Bacillus pumilis M were ineffective and they shown no noticeable influence on the content of agronomically valuable and water-stable aggregates of meadow chernozem.

Soil microbial polysaccharides led to a significant increase in mechanical strength of the indicator units of the same size in air-dry. Polysaccharide of B. mucilaginosus was the most effective in this regard at a concentration of 0.016%: increase of mechanical strength of the different fractions of aggregates was 5–8% as compared to the control. Revisions of the meadow chernozem bacterial polysaccharides of R. phaseoli 8 and B. pumilis M in 0.016% concentration and polysaccharide of B. mucilaginosus at a concentration of 0.002% didn’t accompanied by an increase in mechanical strength of aggregates.

Microbial strain B. mucilaginosus С-3 is promising from the point of view of a biological preparation that improves the soil.

Key words: Bacillus mucilaginosus, Rhizobium phaseoli 8, Bacillus pumilis M, exopolysaccharides, structure, water-stable aggregates, meadow chernozem.