The decomposition of buried human remains on cemeteries can be delayed in poorly aerated graves due to high water levels and a low permeable pore system for oxygen and water transport. With aim to improve the soil aeration properties in the burial environment, the addition of quicklime (CaO) to the grave backfill was tested. Quicklime is expected to promote a stronger aggregation and stabilization of the backfilled soil mainly by forcing an immediate dehydration and particle cementation processes. Two different grave simulations (without buried corpses) were prepared: (1) mixing the grave backfill with 20 kg m−3 quicklime (“CaO”) and (2) backfill without CaO (“NIL”) on a cemetery in Northern Germany. The soil type was a Terric Anthrosol (Stagnic) with a loamy sand texture. Undisturbed soil cores were taken from two depths before and after excavation and backfill at regular intervals of 3 months in order to analyze changes in (1) gaseous transport functions expressed by air‐filled porosity, air permeability (air permeameter), gas diffusivity (double chamber method) and related pore continuity indices as well as in (2) soil respiration (alkali trap method) representing microbial activity. Results clearly demonstrated a more conductive pore system in the CaO variant reflected by higher gas diffusivity and air permeability over 1 year compared to the NIL variant. Pore continuity indices also indicated a more connective pore system for the CaO variant. Effects of CaO application on soil respiration rate differed between the quarterly sampling times. Results indicated that microorganism were still active under alkaline soil conditions induced by CaO application, but the quantitative determination of biologically produced CO2 is influenced by chemical reactions when hydrated quicklime [Ca(OH)2] was reformed to limestone under consumption of CO2. The experiments indicate that the application of quicklime is a promising approach to improve aeration properties of grave soils and is therefore proposed as an adequate method to improve the aeration of burials on cemeteries.

Evaluación de suelos intervenidos por sepulturas, en un contexto bio-geoarqueológico. IX ResumenLos Necrosoles son suelos relacionados con entierros, formados por los cambios que produce la inhumación de cuerpos humanos. Este estudio mostró las aproximaciones interdisciplinarias que integran conocimientos respecto a los suelos de cementerios contemporáneos y antiguos e inhumaciones clandestinas que producen interés científico, bio-geo-arqueológico y forense reciente, además de la compilación acerca de los estudios enfocados en los Necrosoles. También plantea la utilidad de la micromorfología de suelos como herramienta potente en el análisis y confirmación de la presencia de Necrosoles o su formación en pedoturbaciones detectadas por los métodos usados en la arqueología y geociencias. Esta investigación surgió a partir de las exhumaciones en tres cementerios rurales, por el cambio de uso de la tierra que denota el Proyecto Hidroeléctrico Ituango, en el cañón del río Cauca en Colombia. El objetivo de este trabajo fue analizar, desde la pedología, las características diagnósticas asociadas a condiciones de enterramiento. Identificamos que los suelos de estos cementerios, respecto a sus referentes naturales, manifiestan variaciones considerables en micromorfología como presencia de microfragmentos de madera de ataúd y de hueso, minerales con orientaciones paralelas, concentración alta de raíces finas al nivel del entierro y mezclas de agregados pedogénicos entre de matrices no pedogénicas. Además identificamos diferencias geoquímicas como concentraciones más altas de S, Fe móvil, P y valores superiores de capacidad de intercambio catiónico efectiva asociados con procesos pedo-antropogénicos.Palabras clave: entierros, suelos de cementerio, micromorfología de suelos, geología forense, cambio de uso del suelo. XSoils evaluation intervened by graves, in a bio-geo-archaeological context.

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.

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