utilization of agricultural waste into terra preta biofertilizer and its impact on crop productivity

This study proposes the conversion of agricultural waste into the biofertilizer terra preta, accompanied by laboratory experiments aimed at processing optimization and soil fertility improvement. thermal treatment of rice husks and straw yielded biochar, with pyrolysis conditions optimized and sorption properties investigated. the optimal pyrolysis temperature was determined to be 300 °c with a residence time of 60 min, under which biochar exhibited the highest sorption activity. the obtained biochar was subsequently mixed with manure and rice husks/straw for composting to produce a substrate suitable for vermicomposting with eisenia fetida (california red worms). the optimal mass ratio for composting was found to be rice husk: manure: biochar = 70:20:10. the resulting compost underwent humification through vermicomposting for 90 days, yielding a product with a humus content of 31.8%, which corresponds to the terra preta concept. the produced terra preta biofertilizer was tested for its effect on crop productivity in melon, tomato, carrot, potato, watermelon, and cucumber cultivation, demonstrating a yield increase of 23–32%. furthermore, the synergistic effect of this biofertilizer in combination with the biopreparation plantobacterin as was examined concerning the phenology of leguminous crops. the findings highlight the potential of terra preta biofertilizer to mitigate soil degradation and promote the rational utilization of agricultural residues such as husks, straw, and manure.