Potential of olive mill wastes for soil C sequestration

Area of Science:

• Agricultural Science
• Environmental Science
• Soil Science

Background:

• Olive mill wastes are abundant byproducts with high lignocellulosic content.
• Slow degradation of these wastes suggests potential for soil carbon sequestration.
• Understanding carbon dynamics during waste management is crucial for environmental sustainability.

Purpose of the Study:

• To evaluate the potential of two-phase olive mill wastes (TPOMW) as a carbon source for soil carbon sequestration.
• To quantify carbon losses throughout the entire lifecycle of TPOMW, from composting to soil application.
• To assess the impact of TPOMW stabilization degree on overall carbon conservation efficiency.

Main Methods:

• Carbon balance analysis was conducted for the complete lifecycle of TPOMW.
• Carbon losses were measured during composting (34 weeks) and subsequent soil incubation (8 months).
• Laboratory conditions were used to simulate composting and soil application processes.

Main Results:

• TPOMW composting resulted in carbon losses ranging from 40.58% to 45.19% of initial carbon.
• Subsequent soil incubation showed only 20.6%–21.9% of added carbon evolved as CO2.
• Total carbon losses were lower than those from composts of different organic origins.
• The degree of TPOMW stabilization did not significantly affect total carbon losses.

Conclusions:

• The low degradation rate of TPOMW during composting and after soil application makes it an attractive material for soil carbon sequestration.
• TPOMW utilization contributes to efficient carbon conservation compared to other organic residues.
• Further research into optimizing TPOMW application for enhanced soil carbon storage is warranted.