Biochar-Urea Peroxide Composite Particles Alleviate Phenolic Acid Stress in Pogostemon cablin Through Soil...

Area of Science:

• Soil Science
• Environmental Chemistry
• Plant Physiology

Background:

• Continuous cropping of patchouli (Pogostemon cablin) is hindered by autotoxic phenolic acids in soil.
• Conventional remediation methods like biochar adsorption or chemical oxidation struggle to efficiently remove these allelochemicals while improving soil ecology.

Purpose of the Study:

• To develop and evaluate a novel biochar-urea peroxide composite particle (BC-UP) for simultaneous phenolic acid removal and soil improvement.
• To assess the impact of BC-UP on patchouli growth, bioactive compound production, soil properties, and rhizosphere microbial community.

Main Methods:

• Batch degradation experiments and electron paramagnetic resonance (EPR) analysis to confirm BC-UP's function.
• Pot experiments applying BC-UP to phenolic acid-stressed patchouli soil.
• Analysis of plant biomass, bioactive compounds, soil physicochemical properties, enzyme activities, and microbial community structure.

Main Results:

• BC-UP application significantly increased patchouli shoot biomass (28.8%) and root surface area (49.3%).
• Total phenolic acid content in rhizosphere soil was reduced by 37.3%, with enhanced bioactive compound accumulation.
• Soil properties (pH, organic matter) and enzyme activities improved, alongside a reshaped microbial community (reduced fungi-to-bacteria ratio).

Conclusions:

• BC-UP effectively mitigates phenolic acid stress via synergistic adsorption and radical oxidation.
• This composite particle improves soil physicochemical properties and restructures the rhizosphere microbiome.
• BC-UP presents a promising remediation strategy for patchouli and other medicinal crops facing continuous cropping obstacles.