Sustainable Nutrient Recovery from Human Urine: a Soil–Plant–Microbe Interaction Study for Enhanced Agricultural Productivity of Talinum fruticosum L (Juss.)

Abstract

Sustainable nutrient recovery from human urine offers a desirable biotechnology approach for improving soil fertility, microbial activity, and crop productivity in low-input farming systems. This study evaluated the effects of 17-day stored human urine on soil–plant–microbe interactions and the reproductive performance of Talinum fruticosum. A completely randomized pot experiment was conducted using two urine application rates (360.10 mL and 620.10 mL) and an untreated control. Soil samples collected before urine application and after harvest were analyzed for bacterial and fungal populations, while reproductive parameters, including days to first flower bud initiation, number of buds, flowers, and fruits, were monitored for 30 days. The 360.10 mL treatment resulted in the earliest flower bud initiation (13 days) and produced the highest numbers of buds, flowers, and fruits, indicating optimal nutrient availability and microbial stimulation for reproductive development. Although the 620.10 mL treatment enhanced reproductive performance compared with the control, its reproductive output was lower than that of the 360.10 mL treatment, suggesting that excessive nutrient input may reduce reproductive efficiency. Microbial populations increased following urine application, with the highest bacterial and fungal counts recorded under the 620.10 mL treatment. Predominant bacterial genera included Bacillus, Flavobacterium, Klebsiella, and Pseudomonas, while Aspergillus, Penicillium, and Rhizopus were the dominant fungal genera. The findings demonstrate that moderate application of stored human urine can enhance soil microbial activity, flowering, and fruit production, highlighting its potential as an affordable and environmentally sustainable biofertilizer for nutrient-efficient agricultural production.