THE EFFECT OF NITRIFICATION INHIBITORS ON HORSE BEAN YIELD AND ON SOIL-MICROORGANISMS

The effects of nitrification inhibitors (CMP, N-Serve and ATC) on hors e bean yield, fixation of air nitrogen and soil microflora were studie d in pot trial. Moreover, in laboratory experiment the influence of th e mentioned compounds on proliferation of R.legwninosarum and dehydrog enase activity was determined. Negative effects of studied inhibitors on horse bean growth and development, nitrogen fixation and activity o f some strains Rhizohium dehydrogenases were found. Nitrification inhi bitors reduced the soil dehydrogenases activity but effects on phospha tases and urease activity were not so pronounced. They did not select oligo- and macrotrophic bacteria, Azotohacter sp., actinomycetes and f ungi, ammonifiers, cellulolytic, proteolytic and mineral nitrogen fixi ng microorganisms.