Soil chemical properties affecting NH₄⁺ sorption in forest soils

Abstract

ZusammenfassungFourteen European forest soils from the boreal to the mediterranean climate on different parent materials were investigated with respect to their ability to store NH4+ in exchangeable form, using sorption isotherms. Distribution coeflicients for NH4' sorption per unit weight of soil were in the range of 0.02 to 0.77. NH4+ sorption coemcients were usually highest in the forest floor of a given soil.NH4' sorption behaviour of mineral soil horizons was correlated to soil parameters that are determined during routine soil analysis. A combination of CEC and base saturation explained up to 95% of the variability of NH4+ sorption. In the forest floors, variability in NH4+ sorption could not be explained quantitatively from independent soil parameters. The affinity of the sorption sites for NH,' was the most important factor for explanation of the variability in NH4+ sorption in the forest floors but was of low importance in mineral soil horizons.As NH4' exchanges predominantly base cations, susceptibility of NH4+ to transport through the soil profile increases with low base saturation of a soil as well as with low CEC values.

Nitrogen additions mobilize soil base cations in two tropical forests

“…displacement of base cations on soil surfaces has been observed across 14 European forests with varying climates (Matschonat and Matzner 1996). Another mechanism for potential cation mobilization with N addition is the acidification effect described above, particularly with the high background nitrification rates at these sites, where nitrification accounts for the fate of [50 % of NH 4 ?…”

Clostridium akagii sp. nov. and Clostridium acidisoli sp. nov.: acid-tolerant, N2-fixing clostridia isolated from acidic forest soil and litter.

“…Upper soil horizons at these sites exhibited an approximate pH of 3. Beech litter and Ah horizon soil (the deeper organic layer in which fine organic matter dominates) were collected at the Schneeberg-Schacht site which is populated primarily by beech (Fagus sylvatica) (Matschonat & Matzner, 1996). At the Waldstein site, peatbog soil was collected from a bog area with peat accumulation and Oh horizon soil (the mineral layer which contains up to 15 % humus) was collected from the Waldstein\Coulissenhieb site which is populated primarily by Norway spruce (Picea abies).…”

“…At the Waldstein site, peatbog soil was collected from a bog area with peat accumulation and Oh horizon soil (the mineral layer which contains up to 15 % humus) was collected from the Waldstein\Coulissenhieb site which is populated primarily by Norway spruce (Picea abies). These sites have been described previously by Matschonat & Matzner (1996). Characteristics of the peat-bog soil were : soil dry weight, 15 % ; organic carbon, 471 g kg -" ; carbon to nitrogen ratio, 17n8.…”

The fate of 15N-labeled nitrogen inputs to pot cultured beech seedlings

“…This can be explained by the preference of ammonium to nitrate by soil microorganisms, followed by higher microbial immobilization of ammonium and also adsorption of ammonium through pure physicochemical reactions onto exchange sites of organic matter, while nitrate due to a lower retention capacity relative to ammonium is lost mainly into leachate (e.g. Matschonat and Matzner 1996;Aber et al 1998). This could be seen after two growing seasons of 15 N tracer application that more 15 N-nitrate than 15 N-NH 4 + were incorporated into leachate (Table 6).…”