Utilization of Urine for Cultivation of Selected Vegetable Crops in Backyard “Peeponics”

Abstract

This study evaluated the use of urine for soilless cultivation (as Peeponics) of Amaranthus viridis and Corchorus olitorius vegetables. This is a laboratory-based experiment involving optimization of amount of urine and dilution required for optimal growth of the test plants. Based on laboratory results, the experiments were scaled up. About 50 L of raw urine was collected from a male postgraduate student’s hall of residence, University of Ibadan, Ibadan, Nigeria. Water from Awba Dam, a natural lake within University of Ibadan, was used as the control. Viable seeds of Amaranthus viridis and Corchorus olitorius were collected from Department of Agronomy, University of Ibadan, and germinated in a nursery for 10 days before transplanting. The raw urine was diluted with varying amount of water in the ratio 1:1 through 1:50. Nutrients in urine media (nitrogen, phosphorus, potassium) and biomass indicators of plant growth (height, weight, number of leaves and leaf area) were determined using standard procedures. Urine dilution ratios below 1:25 did not support the experimental plants growth within a week. Plant height (cm), stem girth (cm), number of leaves (sheets) and leaf area (cm2) of Amaranthus viridis and Corchorus olitorius cultivated on Urine Dilution Ratio (UDR) 1:35 and 1:45 were higher at the end of week 3 compared to other dilutions and control. Percentage reduction of nutrients (NPK) in the media of Amaranthus viridis cultivated on UDR 1:45 was several folds higher (N = 59.9%, P = 100%, K = 55.3%) compared to that of UDR 1:35 (N = 38.5%, P = 49.1%, K = 37.6%). In the control water, the nutrients were totally removed during the experimental period. Growth of Corchorus olitorius cultivated on both UDR 1:35 and 1:45, was significantly higher at the end of week 6. A significant negative correlation was observed between Corchorus olitorius plant height and Phosphorus (r = -0.0418; p < 0.05) removal in the media. The study concluded that the use of diluted human urine for soilless cultivation of vegetables, if encouraged, could promote food security and environmental sustainability at household level in communities.