Iron modification to silicon-rich biochar and alternative water management to decrease arsenic accumulation in rice...

Area of Science:

• Agricultural Science
• Environmental Science
• Soil Science

Background:

• Arsenic (As) contamination in rice poses a global food safety challenge.
• Integrated approaches to reduce As in rice agro-ecosystems are lacking.
• Sustainable rice production requires managing As accumulation in grains.

Purpose of the Study:

• To investigate the efficacy of integrated iron-modified rice hull biochar (Fe-RBC) and water management on As dynamics.
• To reduce As accumulation in rice grains under paddy agro-ecosystem conditions.
• To assess the impact on rice yield and grain quality.

Main Methods:

• Field study using rice cultivar Ishikari irrigated with As-containing water.
• Treatments included Fe-RBC with flooded or intermittent water management, and conventional flooded or intermittent water management.
• Analysis of As, Fe, and Si concentrations, microbial communities, and rice grain As levels.

Main Results:

• Fe-RBC treatments increased grain weight and Fe/Si concentrations in pore water.
• Fe-RBC reduced the As/Fe ratio and abundance of Fe(III)-reducing bacteria.
• Fe-RBC with intermittent water management significantly decreased As accumulation in all plant parts, including grains.

Conclusions:

• Integrated Fe-RBC and intermittent water management effectively reduces As in rice grains.
• This approach enhances rice yield and produces safer grains in As-endemic areas.
• The strategy supports sustainable agriculture and food security goals.