Further evidence concerning the importance of soil air‐filled porosity, soil organic matter and plants for denitrification

Abstract

Previous experiments with artificially compacted mixtures of soils derived from two hori7ans of a mollic luvisol have shown the significmce of air-filled porosity. organic C content and presence of roots for denitrification. To test the validity of these results for natural conditions undisturbed soil cores were taken during tillering from fields cropped to wheat. Denitrification was measured at diffcrcnt constant soil moisture levels. The denitrification rates were in agreement with those found in the earlier experiments. In the light of the new data the previously established regression function parameters were only slightly modified. This confirmed our former findings that the effect of low air-filled porosity and high soil organic C on denitrification was greater in cropped than in uncropped soil.

Denitrification Losses from Sandy and Sandy Loam Soils under Spring Barley Fertilized with Slurry and Ammonium Nitrate

“…This conclusion was also reached in studies by Groffman & Tiedje (1991) of soils with different textures and by Prade & Trolldenier (1989) of undisturbed soil taken out in April in two consecutive years. Table 3.…”

Relationships between denitrification rate and determinant soil properties under barley

“…Studies have followed two emphases: the physical and chemical conditions under which the process occurs have been modelled (Grundmann and Rolston 1987 ;Grundmann et al 1988;Prade and Trolldenier 1989) ; less frequently, biological parameters such as denitriffing enzyme activity (DEA) and most-probable-number (MPN) denitrifier counts have been measured to identiff the microbial mechanisms of rate increase (Martin et al 1988; Parsons et al l99l).…”