Effect of Irrigation with Treated Rural Sewage Effluent on Soil in a Greenhouse

摘要

In order to use limited water resources efficiently, treated sewage effluent usage for irrigation is receiving increasing attention worldwide, including Japan. The main obstacle extending the use of treated sewage effluent for irrigation is the water quality: higher concentration of salts, organic matters and nutrients compared to natural water. The treated sewage effluent has a possible impact on soil environment in greenhouse irrigation where there is no rainfall. In this study, we conducted two irrigation cases by treated rural sewage effluent and tap water for a tomato cultivation and examined the effects of greenhouse irrigation on soil environment. We measured sodium ion, chloride ion and DOC concentrations in soil extract before and after cultivation. Sodium ion and chloride ion concentrations were decreased, and DOC concentration was increased by cultivation in both cases. Changes in these concentrations were no significant differences between the both cases. This work was financially supported by "Pilot program of international collaborative research (Collaborative research based on a joint call with Israel)" under "Commissioned projects for promotion of strategic international collaborative research" funded by MAFF, and JSPS KAKENHI Grant Number JP17K08014.