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

R Soria; N Rodríguez-Berbel; R Ortega; M E Lucas-Borja; I Miralles

doi:10.1016/j.jenvman.2021.112894

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

J Environ Manage. 2021 Sep 15:294:112894. doi: 10.1016/j.jenvman.2021.112894. Epub 2021 Jun 10.

Authors

R Soria¹, N Rodríguez-Berbel¹, R Ortega¹, M E Lucas-Borja², I Miralles³

Affiliations

¹ Department of Agronomy & Center for Intensive Mediterranean Agrosystems and Agri-food Biotechnology (CIAIMBITAL), University of Almeria, E-04120, Almería, Spain.
² Department of Agroforestry Technology and Science and Genetics, School of Advanced Agricultural Engineering, Castilla La Mancha University, Campus Universitario S/n, E-02071, Albacete, Spain.
³ Department of Agronomy & Center for Intensive Mediterranean Agrosystems and Agri-food Biotechnology (CIAIMBITAL), University of Almeria, E-04120, Almería, Spain. Electronic address: imiralles@ual.es.

PMID: 34119984
DOI: 10.1016/j.jenvman.2021.112894

Abstract

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 < 0.05) in soils with sewage sludge and their mixtures in comparison to vegetable compost. Garden compost had low emission rates, similar to soils without amendment and showed lower CO₂ emission rates than the rest of the restoration treatments. Nevertheless, CO₂ emissions decreased in each field campaign over time, showing that all restored soils had lower emissions than natural soils at the end of the sampled period. The different composition of organic amendments had a different effect on soil CO₂ emissions. DistLM analysis showed that soil properties such as total organic carbon, total nitrogen, pH and soil moisture, associated with rainfall periods, strongly influenced CO₂ emissions, whereas temperature did not affect the CO₂ flow. In conclusion, the compost from plant remains could serve better as treatment to restore degraded soils in drylands than sewage sludge because of its lower CO₂ emissions and concomitant effect on climate warming and carbon balance.

Keywords: Organic amendments; Priming effect; Recycled waste; Restored soil; Soil CO₂ emissions; Soil respiration.

MeSH terms

Carbon Dioxide / analysis
Mining
Soil Pollutants* / analysis
Soil*
Spain

Substances

Soil
Soil Pollutants
Carbon Dioxide