Organic C levels of Ap horizons in North German Pleistocene sands as influenced by climate, texture, and history of land-use

verfasst von
Günther Springob, Sven Brinkmann, Nicole Engel, Holger Kirchmann, Jürgen Böttcher
Abstract

We evaluated the contents of organic carbon (Corg) of Ap horizons from 11 North German study areas along a Southeast to Northwest precipitation gradient with respect to their general levels and as related to C : N ratio, soil texture (clay content), bulk soil density, climate, and historical land-use since 1780. The focus was on sandy soils, with the largest group of samples originating from 308 km2 of the Fuhrberg catchment north of Hannover/Lower Saxony. Data from loess areas were used for comparisons. Major aims were (1) to quantify current Corg stocks, (2) to provide data on site-specific, steady-state Corg levels in old arable soils, and (3) to identify the main controls of Corg levels in the studied sands. The mean Corg content in sandy, well-drained, old Ap horizons (uplands, > 200 years under cultivation, near steady-state) increased with precipitation from < 8 g kg-1 in the dry eastern parts of the study area (530 mm year 1, 8.3°C) to 25 g kg-1 in the moist Northwest (825 mm year-1, 8.4°C). The Corg levels in lowlands which have been drained for more than 40 years were approximately 3 g kg-1 higher than those of uplands under a similar climate. The factor clay content had no predictive value because low contents were associated with high Corg levels. Large proportions of refractory organic matter in sands resulting from specific features of historical land-use and soil development (calluna heathland, heath plaggen fertilization, podzolization) appeared to be the most probable reason for such high Corg levels. However, the high Corg levels of these old arable sites were still exceeded by those of younger arable areas formerly under continues grassland. A chrono-sequence suggested that a period of about 100 years is necessary until a new steady-state Corg level is established after conversion of grassland into arable land. Elevated Corg levels in current Ap horizons were also found for former woodland and heathland soils. The main conclusion is that sands can contain a lot of stable organic matter, sometimes more than finer textured soils.

Organisationseinheit(en)
Institut für Bodenkunde
AG Bodenbiophysik
Externe Organisation(en)
Landesamt für Bergbau, Energie und Geologie (LBEG)
Swedish University of Agricultural Sciences
Typ
Artikel
Journal
Journal of Plant Nutrition and Soil Science
Band
164
Seiten
681-690
Anzahl der Seiten
10
ISSN
1436-8730
Publikationsdatum
12.2001
Publikationsstatus
Veröffentlicht
Peer-reviewed
Ja
ASJC Scopus Sachgebiete
Bodenkunde, Pflanzenkunde
Ziele für nachhaltige Entwicklung
SDG 13 – Klimaschutzmaßnahmen, SDG 15 – Lebensraum Land
Elektronische Version(en)
https://doi.org/10.1002/1522-2624(200112)164:6<681::AID-JPLN681>3.0.CO;2-V (Zugang: Unbekannt)