Recycling paper to recarbonise soil

Area of Science:

• Agricultural Science
• Soil Science
• Environmental Science

Background:

• Increasing soil organic carbon (SOC) is crucial for soil health and climate change mitigation.
• Carbon-rich amendments offer a direct method to enhance soil carbon sequestration.
• Paper crumble (PC) is a potential amendment for improving soil properties and carbon content.

Purpose of the Study:

• To evaluate the impact of paper crumble (PC) amendment on soil organic carbon (SOC) levels.
• To assess the long-term carbon storage potential of PC in agricultural soils.
• To investigate the effects of PC on other soil properties and crop yield.

Main Methods:

• Field experiment applying PC at rates of 50 to 200 t ha^-1.
• Utilisation of a modified Roth-C carbon fate model for long-term (50 years) carbon storage prediction.
• Analysis of soil properties including bulk density, water holding capacity, and cation exchange capacity.

Main Results:

• A 50 t ha^-1 PC amendment increased soil carbon by 12.5 g kg^-1.
• Long-term modelling indicated a potential carbon storage of 0.36 t_OC ha^-1 for a single 50 t ha^-1 application.
• Rotational application (4-yearly) of 50 t ha^-1 PC could lead to a 6.65 t_OC ha^-1 uplift over 50 years.
• Observed benefits included decreased bulk density, increased water holding capacity, and increased cation exchange capacity.
• No significant increase in wheat crop yield was observed.

Conclusions:

• Paper crumble (PC) amendment is effective in increasing soil organic carbon (SOC) and enhancing soil quality.
• PC application presents a viable strategy for significant soil recarbonisation and long-term carbon sequestration.
• Despite no yield increase, the soil health and carbon benefits support PC as a valuable soil conditioner.