Explicating the Fertilizing Potential of Anaerobic Digestate on Soil Quality, Growth and Yield Responses of Solanum lycopersicum var. Kashi Aman

Abstract

Application of anaerobic digestates (ADg(s)) from organic wastes as bio-fertilizer in an agricultural field is economically viable and an environmentally sustainable alternative. The study aimed to utilize ADg(s) (25, 50, 75 and 100% w/w) from the organic proportion of flower-waste (FW), sewage-sludge (SS) and municipal solid wastes (OFMSW) as soil amendment to investigate soil nutrient status and growth performances of tomato (Solanum lycopersicum var. Kashi Aman). Organic carbon, nitrogen, phosphorous, exchangeable Na, K and Ca ions, and enzymatic activities were increased with increase in ADg(s) amendment in soil with relatively higher increase under OFMSW amendment. Metal ion contents in the soil amended with ADg(s) were in the order, Fe > Zn > Mn > Cu > Ni > Pb > Cr > Cd and their contents increased with increasing OFMSW, SS and FW. Plant biomass and fruit-yield were higher under all ADg(s) amendments compared to the control, with maximum yield under 100% SS. Contents of Fe, Zn, Mn, Cu, Cr and Pb in the entire plant were positively correlated with the yield under all ADg(s) amendments. Based on translocation and bioconcentration factors, tomato was found to be efficient in accumulation of metal ions except Cd. Contents of metal ions in the fruit were within FAO/WHO limit, but Fe content under T2, T3 and T4 treatments with OFMSW and SS as well as T3 and T4 treatments with FW were above the limit. Hence, the study suggests utilization of 25% of OFMSW, SS and FW as bio-fertilizer to improve the soil fertility and tomato yield without the risk of metal contamination. © University of Tehran 2024.