Porównawcze badania nad występowaniem bakterii w hydroponicznych uprawach sałaty (Lactuca sativa L.) z azotanowaą i amonową formą azotu w pożywce [Comparative studies on the occurrence of bacteria in hydroponic cultures of lettuce (Lactuca sativa L.) enriched with nitrate or ammonia forms of nitrogen in the nutrient medium]

Abstract

The experiment demonstrated the greatest number of bacteria on the surface of roots immersed in nutrient solution, next on the epidermis of the parts of roots remaining in the air space above the nutrient solution and on the roots growing in the seed-bed; a smaller number in the seed-bed itself and the smallest number in the nutrient solution. The population of bacteria consisted of up to 90% short rod of bacilli. The total number of bacteria in hydroponic culture with ammonium was higher than in that with nitrate. As a rule the bacteria belonging to the separate physiological groups, participating in nitrogen metabolism (ammonifying, proteolytic, proteinizing, denitrifying and oligonitrophilic bacteria) appeared to be more numerus in the culture with ammonium than in that with nitrate. The growth of plants in hydroponic culture with ammonium was weaker than in that with nitrate.