Influence of Fertigation with Anaerobically Treated Domestic Wastewater on Soil Chemical Properties, Growth and Yield Characteristics of Greenhouse Maize Plants

Abstract

Irrigation with effluents is becoming widespread around the world because of uncertain rain-fed agriculture and water scarcity. Hence, the objective of this paper is to investigate the influence of fertigation with anaerobically treated domestic wastewater on soil chemical properties, growth and yield characteristics of greenhouse maize plants using standard methods. Application of treated effluents for irrigation of crops in greenhouses may have impact on soil nutrients and crop yield depending on the origin of wastewater and the type of treatment. A greenhouse experiment was carried out to explore the effects of irrigation with wastewater treated in an anaerobic digester integrated with an Anaerobic Baffled Reactor (ABR) on chemical properties of soil, maize yield and growth characteristics. Three replications of plots irrigated with treated effluent (treatment) and plots irrigated with fresh water (control) were used. The treated wastewater pH was 7.78±0.3, with higher concentrations of BOD₅, COD, PO₄^-, NO₃-N and NH₃-N than fresh water. Irrigation using anaerobically treated wastewater showed significant improvement (P<0.05) in soil PO₄^- and organic matter, but had no effect on soil salinity and alkalinity. Leaf length and leaf area Index significantly increased (P<0.05) by 12.2% and 32.02% respectively in treatment plots. Yield characteristics: weight of 1000 grains, mass of grains per cob and yield of grains portrayed significant improvement (P<0.05) in treatment plots. In treatment plots, grain yield was 44.9% higher, grains were 13.9 % heavier and weight of grains per cob was 32.1% higher than those from the control plots. Thus, short-term irrigation with anaerobically treated domestic effluent from the anaerobic digester integrated with ABR enhanced the yield of greenhouse maize. On long-term application, soil monitoring is advised every farming cycle for early detection undesirable changes to inform the required remedial measures.