Estimating soil organic carbon changes in managed temperate moist grasslands with RothC

Area of Science:

• Soil Science
• Ecology
• Climate Science

Background:

• Temperate grassland soils are significant carbon sinks.
• Accurate estimation of soil organic carbon (SOC) changes is crucial for greenhouse gas (GHG) grassland budgets.
• The Rothamsted Carbon (RothC) model is widely used for SOC estimation but requires refinement for grasslands.

Purpose of the Study:

• To improve RothC model predictions of SOC in managed temperate moist grasslands.
• To evaluate the impact of modifications to soil water function, organic matter input pools, plant residue quality, and livestock trampling on RothC performance.

Main Methods:

• Modified the RothC model's soil water function, exogenous organic matter (EOM) entry pools, and plant residue C input quality.
• Incorporated a livestock trampling effect.
• Conducted sensitivity analysis and validated predictions against European grassland experiment data.

Main Results:

• Default RothC model performance was 78%.
• Modified soil water function (95%) and plant residue components (86%) significantly improved SOC predictions.
• Changes in C input quality (80%) and livestock trampling (46%) showed limited improvement.

Conclusions:

• Modifying the soil water function and plant residue components enhances RothC's predictability in managed grasslands.
• Adding livestock trampling complexity did not improve model accuracy.
• Refined RothC parameters are valuable for grassland carbon stock assessments.