Nutrient conservation during spent mushroom compost application using spent mushroom substrate derived biochar.

Area of Science:

• Agricultural Science
• Environmental Science
• Soil Science

Background:

• Spent mushroom compost (SMC) enhances soil but risks nutrient leaching.
• Nitrogen, phosphate, and organic matter in SMC can contaminate groundwater.

Purpose of the Study:

• To evaluate SMS-derived biochar as a nutrient conservation strategy.
• To assess the impact of biochar pyrolytic temperature on its properties.
• To determine the effectiveness of SMS-based biochar in reducing nutrient leaching from SMC.

Main Methods:

• Biochars were prepared from SMS at different pyrolytic temperatures (550°C, 650°C, 750°C).
• Biochar physical and mineralogical properties were characterized (surface area, pore volume, XRD).
• Column leaching tests were conducted using mixed treatments of SMC and SMS-based biochar.

Main Results:

• Biochar surface area and pore volume increased with pyrolytic temperature.
• SMS-750-800 biochar, when mixed with SMC, reduced total nitrogen (TN) by 43% and chemical oxygen demand (COD_Cr) by 66% in leachate.
• Increasing SMS-750-800 dosage from 1% to 5% reduced COD_Cr by 54%, confirming nutrient retention.

Conclusions:

• SMS-based biochar is effective in retaining nutrients from SMC.
• Combined application of SMC and SMS-based biochar is a viable strategy to reduce TN and COD_Cr leaching.
• Biochar produced at higher temperatures exhibits enhanced nutrient retention capabilities.