Microbial biomass and respiration in soils derived from lignite ashes: a profile study

• Published in: Journal of plant nutrition and soil science 2004-08, Vol.167 (4), p.449-456
• Main Authors: Machulla, G, Zikeli, S, Kastler, M, Jahn, R
• Format: Article
• Language: English
• Subjects: Agronomy. Soil science and plant productions; anthropogenic soil types; anthropogenic soils; ash; biological activity in soil; Biological and medical sciences; bulk density; cadmium; cation exchange capacity; chemical characteristics; coal; coal combustion ashes; combustion; Fundamental and applied biological sciences. Psychology; General agronomy. Plant production; heavy metals; landfills; lignite; microbiological properties; polluted soils; soil chemistry; soil microorganisms; soil pH; soil pollution; soil respiration; Soil science; Soil-plant relationships. Soil fertility; Soil-plant relationships. Soil fertility. Fertilization. Amendments; subsoil; topsoil
• ISSN: 1436-8730; 1522-2624
• DOI: 10.1002/jpln.200421392

Microbial biomass C and soil respiration measurements were made in 17–20 yr old soils developed on sluiced and tipped coal‐combustion ashes. Topsoil (0–30 cm) and subsoil (30–100 cm) samples were collected from three soil profiles at two abandoned disposal sites located in the city area of Halle, Saxony‐Anhalt. Selected soil physical (bulk density and texture) and chemical (pH, organic C, total N, CEC, plant available K and P, and total Cd and Cu) properties were measured. pH values were significantly lower while organic C and total N contents and the C : N ratio were significantly higher in the topsoil than in the subsoil indicating the effects of substrate weathering and pedogenic C accumulation. Likewise, microbial biomass C, K2SO4‐extractable C, and soil respiration with median values of 786 μg biomass C g–1, 262 μg K2SO4‐C g–1, and 6.05 μg CO2‐C g–1 h–1, respectively, were significantly higher in the topsoil than in the subsoil. However, no significant difference was observed in metabolic quotient between the topsoil and the subsoil. Metabolic quotient with median values of 5.98 and 8.54 mg CO2‐C (g biomass C)–1 h–1 for the 0–30 cm and 30–100 cm depths, respectively, was higher than the data reported in the literature for arable and forest soils. Microbial biomass C correlated significantly with extractable C but no relationship was observed between it and total N, Cd, and Cu contents, as well as plant‐available K and P. We conclude that the presence of the remarkable concentration of extractable C in the weathered lignite ashes allowed the establishment of microbial populations with high biomass. The high metabolic quotients observed might be attributed to the heavy‐metal contamination and to the microbial communities specific to ash soils. Mikrobielle Biomasse und Atmung in aus Braunkohleaschen entstandenen Böden – eine Studie an Bodenprofilen Der mikrobielle Biomasse‐C und die Bodenatmung wurden in 17–20 Jahre alten, aus verspülten und verkippten Braunkohleaschen entstandenen Böden charakterisiert. Ober‐ (0–30 cm) und Unterbodenproben (30–100 cm) waren aus drei Profilen an zwei stillgelegten Deponiestandorten im Stadtgebiet von Halle (Sachsen‐Anhalt) entnommen. An diesen Bodenproben wurden ausgewählte physikalische (Lagerungsdichte, Textur) und chemische Eigenschaften (pH, organischer C, Gesamt‐N, KAK, pflanzenverfügbares K und P, Gesamt‐Cd und ‐Cu) ermittelt. Die pH‐Werte waren im Oberboden signifikant niedriger, der organische C, der Gesamt‐N und