Soil amendments from recycled waste differently affect CO₂ soil emissions in restored mining soils under semiarid conditions

• Published in: Journal of environmental management 2021-09, Vol.294, p.112894-112894, Article 112894
• Main Authors: Soria, R., Rodríguez-Berbel, N., Ortega, R., Lucas-Borja, M.E., Miralles, I.
• Format: Article
• Language: English
• Subjects: Organic amendments; Priming effect; Recycled waste; Restored soil; Soil CO₂ emissions; Soil respiration
• ISSN: 0301-4797; 1095-8630
• DOI: 10.1016/j.jenvman.2021.112894

Drylands affected by serious disturbances such as mining activities lose their vegetation cover and organic soil horizons, becoming CO2 emissions sources. Applications of organic amendments could be a good restoration solution that favours vegetation establishment and soil carbon sequestration; however, they are also associated with CO₂ emissions. Experimental plots with different organic amendments (sewage sludge, garden and greenhouse vegetable composts, and mixtures of both) and unamended soils were installed in a quarry in southeast Spain. The aim of this study was: i) to evaluate the magnitude and changes of in situ CO₂ emission from each experimental plot during a year and a half, and ii) to assess the effects of several physical–chemical (total organic carbon, total nitrogen, water retention, pH and electrical conductivity) and environmental parameters (moisture and temperature) in CO2 emissions. The results showed an initial CO2 emission (priming effect), produced from all restored plots just after the application of the organic amendment, which was significantly higher (P