Evaluation of biochar and Agaricus bisporus spent compost on some physiological, production characteristics of tomato Solanum lycopersicum L.

This study was conducted for the period 2024-2026 in the laboratories and fields of the College of Agriculture, Tikrit University, aimed to evaluation of biochar prepared from various plant sources and Spent mushroom compost (SMC) for enhanced growth and productivity parameters in Barcelona cultivar tomato plants , for the photosynthetic Rate SMC at 5% concentration achieved the highest rate of 123.7 mg cm⁻² day⁻¹, surpassing Sesban biochar at 5% (101.3 mg cm⁻² day⁻¹) and the control (61.32 mg cm⁻² day⁻¹). All treatments improved photosynthesis, with efficacy increasing at higher doses. SMC at 5% yielded superior dry vegetative weight (101.73 g plant-1) and root dry weight (14.18 g plant-1), compared to the control (9.36 g plant-1 root weight). Sesban biochar followed closely at 98.88 g plant-1 (vegetative) and 13.75 g plant-1 (root), while palm biochar recorded 96.01 g plant-1 (vegetative) and 13.07 g plant-1 (root). SMC at 5% maximized root activity at 138.44 mg g⁻¹ h⁻¹ versus the control's 52.54 mg g⁻¹ h⁻¹. Sesban biochar at 5% reached 127.48 mg g⁻¹ h⁻¹, highlighting the influence of feedstock on root dynamics. Peroxidase activity peaked with SMC at 5% (1.78 units mL⁻¹) over the control (1.03 units mL⁻¹); Sesban biochar hit 1.63 units mL⁻¹. Catalase activity was highest in SMC at 5% (403.78 units g⁻¹ FW), exceeding Sesban (397.49 units g⁻¹ FW) and the control (281.11 units g⁻¹ FW). SMC at 5% produced the top yield of 661.23 g plant-1, followed by Sesban biochar (641.04 g plant-1) and palm biochar (612.93 g plant-1), against the control's 448.55 g plant-1. Higher concentrations consistently drove greater improvements across all metrics.