Carbon mineralization and distribution of nutrients within different particle-size fractions of commercially produced olive mill pomace

• Published in: Bioresource technology 2011-11, Vol.102 (21), p.9997-10005
• Main Authors: Gómez-Muñoz, Beatriz, Bol, Roland, Hatch, David, García-Ruiz, Roberto
• Format: Article
• Language: English
• Subjects: Agronomy. Soil science and plant productions; Biological and medical sciences; By-products; C mineralization; Carbon; Carbon - analysis; Carbon - chemistry; carbon nitrogen ratio; Cellulose - analysis; Chemical Fractionation - methods; compost quality; Composted olive mill pomace; Composting; Fundamental and applied biological sciences. Psychology; General agronomy. Plant production; Industrial Waste - analysis; Lepidium sativum - growth & development; Lignin - analysis; Mills; Mineralization; Minerals - chemistry; Nitrogen - analysis; nutrient content; Nutrients; Olea; Olea - chemistry; Olives; Optimization; organic matter; organic production; organic soils; Other nutrients. Amendments. Solid and liquid wastes. Sludges and slurries; Particle Size; Particle-size fraction; Phosphorus - analysis; Polyphenols - analysis; pomace; Principal Component Analysis; Soil; Soil (material); soil conditioners; soil treatment; Soil-plant relationships. Soil fertility. Fertilization. Amendments
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2011.08.009

► Nutrient and carbon mineralization of composted olive mill pomace were analyzed. ► Quality and particle distribution differed according to the material co-composted. ► Higher content of nutrients and lower carbon contents were found in finer particles. ► Larger particles had higher contents of organic matter and phytotoxic properties. ► Particle size separation facilitates better management of this compost. Composting is a realistic option for disposal of olive mill pomace (OMP) by making it suitable as a soil amendment for organic farming. The chemical and physical characteristics and contribution of particle-size fractions to total nutrients and carbon mineralization of seven commercial composts of OMP (COMP) were investigated. Higher proportions of manure, co-composted with OMP, reduced the organic matter (OM), total carbon and C:N ratio of the product, but increased the content of nutrients and fine particles. The fine particles had higher nutrient contents, but less OM and carbon and, unlike larger particles, did not exhibit any phytotoxicity. Less than 1.5% of added carbon was mineralized in whole compost, but a lower rate was found with larger particles. Separation of COMP by particle size fractionation and application as a soil conditioner is recommended for better optimization of COMP with the