Microbial activity and biomass of cellulose amonium and nitrite oxidizers in wheat fields under conventional and integrated management

The aim of this paper was to evaluate the effect of different management systems on the microbial activity and the biomass of cellulose and nitrogen oxidizers. The experiments were pertormed in 1995 and repeated in 1996. In 1995, we experimented the conventional and integrated no tillage systems on wheat fertilized with urea. In 1996, we repeated the conventional and integrated tillage systems on wheat and added an alternative integrated system the chisel. Our results suggest that changes in C and N turnover were not provoked by changes in microbiai biomass but by the activity of the microbial comunity. Nitrogen fertilization with urea can act as a good starter only if it is added at the seeding stage. The nitrogen mineralizable potential of conventional and integrated labored soils were similar.

Key words: microbial biomass, nitrification. tillage systems, wheat.