TY - JOUR AU - Galvez, Antonia AU - Sinicco, Tania AU - Marino, Lorena AU - Cayuela, Maria Luz AU - Mingorance, Maria Dolores AU - Mondini, Claudio PY - 2011/01/01 Y2 - 2024/03/28 TI - USE OF BIOENERGY RESIDUES AS AMENDMENTS: IMPLICATIONS ON SOIL FERTILITY AND SOIL CARBON SEQUESTRATION JF - EQA - International Journal of Environmental Quality JA - EQA VL - 6 IS - 6 SE - Articles DO - 10.6092/issn.2281-4485/3825 UR - https://eqa.unibo.it/article/view/3825 SP - 39-48 AB - The increasing use of renewable energy sources as substitutes to fossil fuels has provoked an increase in the production of bioenergy residues. These residues could be effectively used for the recovery and conservation of soil fertility. However, the effect of the organic residues on the soil ecosystem is different depending on their physico-chemical characteristics and, particularly, the knowledge of the impact of bioenergy residues on soil quality is still limited. The aim of this work is to study the effects of different bioenergy residues on C and N mineralization and soil microbial content and activity. A degraded soil (clay 49.7%, pH 7, OC 0.37%) from Southern Spain was amended (0.5% w/w) with four different bioenergy residues (anaerobic digestate, rapeseed meal from biodiesel production, bioethanol residue and biochar) and three other organic residues commonly used as organic amendments (wastewater sludge and two composts). The amended soil was then incubated for 30 days at 20 ºC. During incubation soil CO2 evolution was measured every 4 hours by means of an automatic chromatographic system. After 2, 7 and 30 days of incubation the following parameters were also analysed: K2SO4-extractable C, N, NO3 -, NH4 + and P, microbial biomass C and some enzymatic activities involved in the cycle of the main nutritive elements (β-glucosidase, arylsulfatase, esterase, alkaline and acid phosphatase and leucine aminopeptidase). Soil addition of the different residues led to a general increase in C and N mineralization, in the availability of nutrients and in the microbial content and activity, but with remarkable different values and dynamics. The only exception was represented by biochar that did not cause any significant variations of the measured parameters with respect to the control. The obtained results demonstrate that bioenergy residues may represent an effective alternative to usual amendments for the recovery and conservation of soil quality. The different physico-chemical characteristics of the residues suggest different uses. Rapeseed meal, bioethanol residue and anaerobic digestate are more suited to improve soil biological fertility, while biochar is more appropriated for the enhancement of soil organic matter content and to promote soil C sequestration. ER -