Biosolids, derived from treated sewage sludge, represent a significant resource in agricultural production, with approximately 70 percent being utilized for land application in the United States. Recognized for their potential as organic fertilizers, biosolids undergo meticulous processing to meet grade AA standards before being blended with locally sourced organic materials, such as woody yard debris, in preparation for municipal distribution. This study delves into the effects of biosolids on plant growth rates using various concentrations ranging from 0% to 30%. Findings revealed that different concentrations of biosolids in soil significantly delay germination by up to two days. Through replicated mesocosm experiments at the Southwest Florida Research and Extension Center (SWFREC), UF/IFAS, Immokalee, we also evaluated the effects of biosolids on basil (Ocimum bacilicum) growth and physiology. Basil was cultivated in half-gallon pots containing various soil amendments of biosolids compost in concentrations of 0%, 5%, 10%, 15% and 30% over a 60-day period. Comprehensive data collection includes measurements of plant height, leaf chlorophyll content, photosynthetic gas exchange, Normalized difference vegetation index (NDVI), fresh and dry plant biomass, and visual ratings. Data analysis of weekly and post-harvest collected data analyzes the implications of biosolid usage in agriculture, shedding light on significant effects on crop productivity, and agricultural sustainability. The treatments with higher biosolid compost concentrations showed an increase in plant productivity, specifically, the fresh biomass of the 30% treatment was 45% more than in the control. Keywords: Biosolids, Organic Fertilizer, Compost, Soil Contaminants, Basil (Ocimum bacilicum), Plant Physiology, Agricultural Systems.
