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

The effects of nitrification inhibitors (CMP, N-Serve and ATC) on horse bean yield, fixation of air nitrogen and soil microflora were studied in pot trial. Moreover, in laboratory experiment the influence of the mentioned compounds on proliferation of R.legwninosarum and dehydrogenase activity was determined. Negative effects of studied inhibitors on horse bean growth and development, nitrogen fixation and activity of some strains Rhizohium dehydrogenases were found. Nitrification inhibitors reduced the soil dehydrogenases activity but effects on phosphatases and urease activity were not so pronounced. They did not select oligo- and macrotrophic bacteria, Azotohacter sp., actinomycetes and fungi, ammonifiers, cellulolytic, proteolytic and mineral nitrogen fixing microorganisms.