Influence of composted food waste and sewage sludge on plant growth enhanced with magnetic fields

Abstract

Sewage sludge and composting food waste have the potential to be used as fertilizer due to nutrient availability. Thus, application of sewage sludge and composted food waste as nutrient sources for plants enhanced with the magnetic field to water the plants was studied. The study focused on nutrient content in sewage sludge powder (SSLG) and liquid from composted food waste (LCFW) from a primary oxidation pond at Taman Sri Pulai, Johor and food waste from wet market Kipmart Tampoi, Johor. Capsicum annum (red chili) was selected as the plant to receive different concentrations of nutrients. In order to increase the efficiency of sewage sludge and composted food waste, magnetized water was applied to irrigate the plants along with SSLG and LCFW. Five different amounts and concentration of SSLG and LCFW were prepared. SSLG was applied to the plant only once at the beginning, while LCFW was applied on a weekly basis. All the plants were watered by the same amount of magnetized and tap water on a daily basis. Plant growth was recorded on weekly basis. The study revealed that there is a significant difference between the application of SSLG and LCFW to the plants and control plants with no SSLG and LCFW in the tap and magnetized water. SSLG and LCFW increased the plant growth up to 83.33% in root, 85.71% in stem and 86.66% in leaves Nitrogen Nitrate (NO3 --N) content, while for Phosphorus (P) content the SSLG and LCFW enhanced 78.57% in root, 73.33% in stem and 75.59% in leaves, for Total Kjedhal Nitrogen (TKN) content organic waste boosted the growth of 59.38% in root, 58.02% in stem and 69.88% in leaves in tap water condition which was higher than control plants. In the meantime for magnetized water, SSLG and LCFW increased up to 84.91% in root, 87.18% in stem and 87.23% in leaves for NO3 --N content, while for P content SSLG and LCFW enhanced growth of 79.31% in root, 75.51% in stem and 80.77% in leaves, for TKN content those organic waste boost 65.02% in root, 85.87% in stem and 71.64%. Magnetic field enhanced nutrient absorption up to 4.76% in root, 11.89% in stem and 16.67% in leaves for NO3 --N content, while for the P content the magnetized water enhanced 17.31% in root, 8.78% in stem and 14.42% in leaves, for TKN content that magnetic treatment boost 29.34% in root, 58.18% in stem and 17.90% in leaves higher than untreated tap water. In conclusion, the application of sewage sludge and composted food waste, enhanced by magnetic water is a viable option for plant growth where the quality of the crops was increased. However, in terms of consumption and safety, other alternatives should also be considered in order to further validate the safety of crops grown with sewage sludge.