PLANT CELL BIOTECHNOLOGY AND MOLECULAR BIOLOGY

Soil degradation and declining organic carbon in vulnerable charland ecosystems threaten long-term agricultural productivity and sustainability. Integrating biochar and trichocompost offers a promising strategy to enhance soil health, improve nutrient retention, and increase carbon sequestration under sustainable farming systems.

This study evaluated the effects of rice husk biochar and trichocompost on soil properties through a two-year field experiment (2022–2024) conducted at two charland sites in Munshiganj, Bangladesh. Two cropping systems—Potato–Groundnut–T. aman and Potato–Mungbean–T. aman—were tested in a randomised complete block design with ten treatments combining biochar (2–3 t ha⁻¹), trichocompost (1 t ha⁻¹), and chemical fertilisers at 100% or 75% of the recommended dose. Soil organic carbon (SOC), cation exchange capacity (CEC), microbial biomass carbon (MBC), pH, and aggregate stability were assessed.

Integrated nutrient management significantly improved soil health in both systems. Macroaggregate stability increased to 64% and 63% in groundnut and mungbean systems, respectively, while microaggregate fractions declined. SOC increased to 0.90% and 0.99%, with SOC stock reaching 18.67 and 19.83 Mg ha⁻¹ and carbon sequestration of 841 and 1032 kg ha⁻¹ in mungbean and groundnut pattern, respectively. Microbial biomass carbon maximized at 385 ppm (groundnut) and at 459 ppm (mungbean) pH improved to 5.36 and 5.95, whereas CEC maximised at 14.59 and 15.74 meq 100 g⁻¹, respectively.

Overall, both the two cropping patterns performed well, the mungbean pattern consistently performed better than the groundnut rotation for SOC, pH, CEC, and microbial populations, thereby confirming the more important contribution to maintaining soil health.

These findings demonstrate that integrating biochar and trichocompost with reduced fertiliser inputs improves soil health and carbon sequestration in charland agroecosystems.