Agricultural Waste-Derived Biochar-Based Nitrogenous Fertilizer for Slow-Release Applications

Area of Science:

• Agricultural Science
• Environmental Science
• Materials Science

Background:

• Rising global populations necessitate increased food production through modern agricultural technologies.
• Conventional nitrogenous fertilizers, while boosting crop yield, suffer from low nutrient use efficiency (20-30%) due to volatilization and leaching.
• Environmental pollution from nitrogenous fertilizers is a significant global concern.

Purpose of the Study:

• To develop a sustainable, slow-release nitrogenous fertilizer using biochar derived from banana leaf sheath (BLS).
• To evaluate the physicochemical properties and nutrient release characteristics of the developed biochar-based fertilizer.
• To assess the potential of biochar to reduce nutrient loss and improve plant nutrient uptake.

Main Methods:

• Banana leaf sheath (BLS) was pyrolyzed at 500 °C for 3 h to produce biochar.
• Nutrient-loaded BLS (NBLS) biochar was prepared for slow-release nitrogenous fertilizer application.
• Characterization of BLS and NBLS biochar using FT-IR, XRD, TGA, SEM, and BET methods.
• Evaluation of water absorbance, retention, swelling ratio, and equilibrium water content.
• Nutrient release studies were conducted over 16 hours.

Main Results:

• BLS and NBLS biochar exhibited excellent water absorbance, retention, swelling ratio, and equilibrium water content.
• Characterization confirmed the porous structure, stability, and functional groups of the biochar, with a peak at 1423 cm^-1 in NBLS indicating NH⁴⁺ loading.
• BET analysis showed specific surface areas of 43.216 m²/g for BLS and 35.014 m²/g for NBLS.
• Nutrient release studies demonstrated a gradual increase in nitrogen release over 16 hours.
• The prepared fertilizer had lower salt index values, indicating a cleaner and more sustainable option.

Conclusions:

• The developed BLS biochar-based fertilizer effectively functions as a slow-release nitrogen source.
• The biochar's properties enhance soil water retention and reduce nutrient leaching compared to conventional fertilizers.
• This sustainable fertilizer holds significant potential for improving agricultural productivity while mitigating environmental pollution.