Soil type and land use effects on tensorial properties of saturated hydraulic conductivity in northern Germany

Abstract

Long‐term soil management can produce anisotropic impacts on soil structure, resulting in differences in horizontal and vertical hydraulic conductivity. As limited data exist on these impacts, this study provides a broad‐scale assessment across 764 soil profiles under arable and grassland use in northern Germany (Federal State: Schleswig‐Holstein). The soils were sampled in the four geological regions: Weichselian glacial region, the sandy outwash region (Lower “Geest”), the Saalian glacial region (Higher “Geest”) and the marshland with alluvial deposits. Saturated hydraulic conductivity (Ks, either in a horizontal (Ks_h) or vertical direction (Ks_v)) and the pore‐size distribution were determined on undisturbed soil samples (100 cm3), whereas the grain size distribution was analysed on disturbed samples from the major soil horizons. This research work presents Ks_h and Ks_v values for representative soil types of the four geological regions down to a depth of 60 cm. Irrespective of the parent material in the four geological regions, arable soils showed a pronounced anisotropy of Ks in the horizontal direction. However, Ks_h and Ks_v also showed a high variability across the geological regions from approximately 1 to 800 cm d−1, whereas the ratio of Ks_h to Ks_v ranged from 0.1 to 500. In the marshland (dominated by Gleysols), the direction‐dependent values were superimposed by sedimentation processes of the marine material and/or structural development processes such as vertical shrinkage or bioturbation processes. Under grassland, the topsoils primarily indicated horizontally anisotropic flow conditions. In the “Geest” area with a high share of dairy farming, both top‐ and subsoils displayed the highest horizontal anisotropy values, indicating the stress‐induced formation of a platy structure caused by trampling, grass harvesting or slurry application with heavy machinery. Soil type (e.g., Stagnic Luvisols, Stagnosols or Anthrosols) and horizon‐dependent horizontal anisotropy were also more pronounced in arable than in grassland subsoils. Highlights Hydraulic conductivity in arable subsoils shows mostly horizontal behaviour. Hydraulic conductivity in grassland topsoils shows mostly horizontal behaviour. The anisotropic degree and its direction depend on land use type and clay content of the soils.

Comparative Effectiveness of Four Nitrification Inhibitors for Mitigating Carbon Dioxide and Nitrous Oxide Emissions from Three Different Textured Soils

“…Three soils varying in soil texture were collected from the following three geological regions of Schleswig-Holstein, Germany: (1) the sandy outwash region (Geest, the outwash region is dominated by Brunic Arenosols or Cambisols, Podzols and Gleysols, as well as Histosols), (2) the Weichselian glacial region in the east (Östliches Hügelland, the Weichselian glacial deposits contain very fertile Luvisols, Cambisols, Anthrosols derived from colluvic material, Gleysols and Rheic Histosols), and (3) the marshland with alluvial deposits in the west (Marsch, the marshland includes different types of Fluvic Gleysols and Histosols) [18]. The selected soils represent the major soil types or climatic zones of the state of Schleswig-Holstein.…”

“…Different results have been reported by previous researchers regarding the relative efficacy of NIs in varying textured soils. Barth et al [18] found that NIs are more efficient in light soils than heavy soils, whereas Akiyama et al [34] found that the effectiveness of NIs was relatively consistent across the various soil types. According to Fisk et al [35], the efficacy of DMPP and DCD diminished with the addition of soil organic matter, and Marsden et al [36] reported decreased efficacy with higher clay content.…”

Natural and anthropogenic compaction in North Germany (Schleswig‐Holstein): Verification of harmful subsoil compactions

“…The influence of long‐term soil management (arable and grassland use) on soil structure and related anisotropy properties of representative subsoil horizons in Schleswig‐Holstein was investigated by Horn et al. (2019). They demonstrated that the horizontal anisotropy of hydraulic conductivity is not only soil type‐ and horizon‐dependent, but also more pronounced in arable than in grassland subsoils.…”

“…They demonstrated that the horizontal anisotropy of hydraulic conductivity is not only soil type‐ and horizon‐dependent, but also more pronounced in arable than in grassland subsoils. Compaction‐induced structural damages in arable soils are primarily attributed to the soil below ploughing depth (≤ 40 cm depth), whereas grassland sites were more affected in the topsoil (Horn et al., 2019). Compared to topsoil compaction, which is almost reversible by tillage, subsoil compaction persists over the long term, because its recovery takes decades (Alakukku et al., 2003; Berisso et al., 2012).…”

“…The intensity of soil use plays a crucial role in the extent of anthropogenic soil compaction in arable (Bertolino et al, 2010;Wiermann, Werner, Horn, Rostek, & Werner, 2000), grassland (Cui, Askari, & Holden, 2014;Holthusen et al, 2018;Koppi, Douglas, & Moran, 1992) and forest soils (Moffat, 1991;Riggert, Fleige, Kietz, Gaertig, & Horn, 2017). The influence of long-term soil management (arable and grassland use) on soil structure and related anisotropy properties of representative subsoil horizons in Schleswig-Holstein was investigated by Horn et al (2019). They demonstrated that the horizontal anisotropy of hydraulic conductivity is not only soil type-and horizon-dependent, but also more pronounced in arable than in grassland subsoils.…”