Moist olive husks addition to a silty clay soil: Influence on microbial and biochemical parameters

• Published in: Journal of environmental science and health. Part B, Pesticides, food contaminants, and agricultural wastes Vol. 41; no. 6; pp. 1019 - 1036
• Main Authors: Perucci, P, Dumontet, S, Casucci, C, Schnitzer, M, Dinel, H, Monaci, E, Vischetti, C
• Format: Journal Article
• Language: English
• Published: Philadelphia, PA Taylor & Francis Group 01.09.2006; Taylor & Francis
• Subjects: Agriculture - methods; Agronomy. Soil science and plant productions; Bacteria - drug effects; Bacteria - enzymology; Bacteria - metabolism; Biodegradation, Environmental; Biological and medical sciences; Biomass; C NMR spectra; clay soils; Dose-Response Relationship, Drug; Enzyme activity; food processing wastes; Fundamental and applied biological sciences. Psychology; General agronomy. Plant production; hulls; microbial biomass; Microbial biomass-C; Moist olive husks; Olea; Olea - chemistry; olives; Other nutrients. Amendments. Solid and liquid wastes. Sludges and slurries; Population Dynamics; Respiration; silty soils; Soil - analysis; Soil - standards; soil amendments; soil enzymes; Soil lipids; Soil Microbiology; soil microorganisms; soil respiration; Soil-plant relationships. Soil fertility. Fertilization. Amendments; Time Factors; Waste Management; Southern Europe; Italy; Europe; Microbial activity; Microbial biomass-C; Biochemical analysis; Enzyme activity; Lipids; Microbial biomass; Soils; 13C NMR spectra; Amendment; Enzymatic activity; Silty clay soil; Olive husk; Soil lipids; Respiration; Moist olive husks; Microbial community; Physicochemical properties
• ISSN: 0360-1234; 1532-4109
• DOI: 10.1080/03601230600808828

To investigate the effects of moist olive husks (MOH-residues) on soil respiration, microbial biomass, and enzymatic (o-diphenoloxidase, β-glucosidase, dehydrogenase and alkaline phosphatase) activities, a silty clay soil was incubated with 0 (control), 8 × 10 3 (D), 16 × 10 3 (2D) and 80 × 10 3 (10D) kg ha −1 of MOH-residues on a dry weight basis. Soil respiration and microbial biomass data indicated that the addition of MOH-residues strongly increased microbial activity proportionally to the amounts added. Data of qCO 2 suggested that the respiration to biomass ratio of the microbial population was strongly modified by MOH-residues additions during the first 90 days of incubation. The qCO 2 data suggested a low efficiency in energy yields from C oxidation during the first 2 months of soil incubation. qFDA seemed to be relatively unaffected for treatments D and 2D as compared to the control, but was significantly lowered by the application of 10D, showing the lowest hydrolytic activity of microbial biomass in this treatment up to 360 days of incubation. o-Diphenoloxidase activity was delayed, and this delay was extended with the addition of larger quantities of MOH-residues. Alkaline phosphatase, β-glucosidase and dehydrogenase activities were in line with the findings on microbial biomass changes and activities. The biological and biochemical data suggest that the addition of a large quantity of MOH-residues (80 × 10 3 kg ha −1 ) strongly modifies the soil characteristics affecting the r- and K-strategist populations, and that these changes last for at least the 360 days of incubation. The data also suggest that application rates exceeding 16 × 10 3 kg ha −1 are not recommended until the agro-chemical and -physical functions of the soil are further studied.