Fodder radish seed cake biochar for soil amendment

Area of Science:

• Agricultural Science
• Environmental Science
• Material Science

Background:

• Fodder radish seed cake (FRSC) is a potential feedstock for biochar production.
• Biochar application is recognized for its role in improving soil fertility and environmental remediation.
• Optimizing pyrolysis conditions is crucial for maximizing biochar yield and quality.

Purpose of the Study:

• To investigate the effect of rotary kiln speed on fodder radish seed cake biochar (FRSC) production.
• To characterize the physicochemical properties of the produced FRSC biochars.
• To evaluate the impact of FRSC biochar application on soil fertility parameters in an acrisol.

Main Methods:

• Pyrolysis of FRSC in a rotary kiln reactor at varying speeds (0, 3, 6 rpm) and a final temperature of 500°C.
• Characterization of biochar properties including yield, volatile matter, ash content, pH, electrical conductivity, cation exchange capacity, and nitrogen content using FTIR.
• Incubation experiments with FRSC biochar at different dosages (5–40 g L⁻¹ soil) in acrisol to assess changes in soil fertility parameters.

Main Results:

• Maximum biochar yield (≈26 wt.%) was achieved at 0 rpm; increased rotary speed reduced volatile matter and increased ash content.
• Produced biochars exhibited alkaline pH (≈9.0), high cation exchange capacity (69–78 cmolc kg⁻¹), and high nitrogen content (≈80 g kg⁻¹).
• Biochar application significantly increased soil macro- and micronutrients, soil pH (from 4.25 to 5.33), and electrical conductivity, while decreasing Al and H+ Al content and soil real density.

Conclusions:

• Pyrolysis conditions, specifically rotary speed, influence FRSC biochar yield and characteristics.
• FRSC biochar possesses favorable properties for soil amendment, including high nutrient content and liming potential.
• Application of FRSC biochar effectively improves soil fertility by enhancing nutrient availability and reducing soil acidity.