Biosolids, derived from treated sewage sludge, represent a significant resource in sustainable 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 soil and seed germination rates using various concentrations ranging from 1% to 7%. Findings reveal that higher concentrations of biosolids in soil significantly delay the germination of lettuce seeds. Through replicated mesocosm experiments at the Southwest Florida Research and Extension Center (SWFREC), UF/IFAS, Immokalee, we evaluate the effects of biosolids on lettuce (Lactuca sativa) growth and physiology. Lettuce was cultivated in 17cm tall pots filled with the soil amendments of biosolids compost in concentrations of 1%, 3%, 5%, and 7% (v/v) over a 60-day period. Comprehensive data collection includes measurements of plant height, leaf chlorophyll content, photosynthetic gas exchange, leaf area index (LAI), fresh and dry plant biomass, visual ratings, and spectral reflectance data at 340-2500 (nm) with a portable spectroradiometer. Data analysis of weekly and post-harvest collected data analyzed the implications of biosolid usage in agriculture, shedding light on significant effects on crop productivity, soil health, and agricultural sustainability. Keywords: Biosolids, Organic Fertilizer, Soil Contaminants, Lettuce (Lactuca sativa), Plant Physiology, Agricultural Systems
