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 (C_org) 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 C_org stocks, (2) to provide data on site-specific, steady-state C_org levels in old arable soils, and (3) to identify the main controls of C_org levels in the studied sands. The mean C_org 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 C_org 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 C_org 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 C_org levels. However, the high C_org 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 C_org level is established after conversion of grassland into arable land. Elevated C_org 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)