green fallow, nitrate nitrogen, ammonium nitrogen, pH, nitrification
Abstract
The impact of fallow management on the dynamics of inorganic nitrogen and pH was evaluated in the field experiment established on Ortic Luvisol during 1996 – 2000. The green fallow was maintained on the field for 6 years without tillage except of mowing. The trial included the following variants of management: 1. uncut green fallow, 2. cut green fallow, biomass remained on the field, 3. cut green fallow, biomass was removed from the field. The soil samples were collected from a 0 to 0,3 m of depth to do analyses of nitrogen and pH. During the growing season (spring, summer and autumn aspects) the contents of ammonia nitrogen, nitrate nitrogen and pH were measured. In each treatment the ammonium nitrogen predominated and with its ratio to total nitrogen ranged around 70 %. In studied variants the significance in nitrate nitrogen content was found only between 2nd and 3rd variant. However, statistically highly significant differences were found between spring and autumn sampling. A year had the most significant effect on changes of inorganic nitrogen, especially amount of rainfall that influenced significantly the activity of nitrification process. The mean values
of nitrate nitrogen were influenced by acid soil pH reaction.
