Denitrification in arable soils in relation to their physico-chemical properties and fertilization practice

摘要: Abstract Increased use of N-fertilizers in the Czech Republic recent decades has been accompanied by increased amounts N compounds general environment, and also shifts rates biological N-processes agricultural soils. Knowledge these changes, including rates, distribution variability denitrification soils is, however, very limited. In period 1993–1995, potential (i.e. denitrifying enzyme activity (DEA) (DP)), was determined at 13 different sites, with differing physico-chemical properties, but which were typical large areas Republic. 1994–1995, more detailed research on four differently fertilized plots a sandy-loam cambisol conducted nine occasions order to analyze seasonal effects establish if than 20 yr fertilization selected environmental factors had influenced denitrification. This completed 1996, when 12 same soil examined. When range investigated, DEA reached values between 15 680 ng 2 O-N g −1 h , corresponding roughly 1.3–16 mg kg d DP 6.6–52 . No significant relationship found DP, indicating independence existing metabolic denitrifier community its for rapid development conditions change favor (DP). While did not correlate any measured correlated highly significantly pH (H O) organic carbon content. Detailed sandy loam showed (i) temporal (ii) an influence long-term characteristics; responded differently: while all moderately soils, decreased (iii) positive correlation many pH, microbial biomass dehydrogenase activity.