Impacts of irrigation with sugar mills’ wastewater and fertilizer on soil chemical and solute-transport properties

Abstract

Impact assessment of wastewater on soil is important to diagnose the potential of wastewater irrigation. By taking this idea into consideration, an experiment was conducted to investigate the chemical and solute-transport properties of soils collected from wheat fields irrigated with sugar mills’ wastewater at North Bengal Sugar Mill (NBSM) and Faridpur Sugar Mill (FSM) of Bangladesh. Soil samples were collected from experimental sites where wheat was grown under both irrigation and fertilizer treatments. The split-plot design with three replications of irrigation (main plot) and fertilizer (sub-plot) were used. Irrigation and fertilizer treatments were defined as I₁ = irrigation with fresh water, I₂ = irrigation with mixed water (fresh water: wastewater = 1:1) and I₂ = irrigation with wastewater; F₁ = Full dose fertilizer, F₂ = Half dose fertilizer and F₃ = No application of fertilizer. Soil samples were chemically analyzed to find their chemical properties and a breakthrough experiment was done to find the solute transport properties. Significant effects were observed for soil chemical properties at both NBSM and FSM sites. At NBSM site, organic-C and S contents of soil increased under I₃ treatment, where as total-N, P, K and Mg contents increased under I₂ treatment. Similarly, Na and Ca contents at FSM site slightly went downunder I₃ treatment. Application of fertilizer also significantly affected soil properties at both sites. Under full dose fertilizer application (F₁) EC, P, K, S, Ca and Mg contents of the soil increased, however, Na content decreased at both sites. Interaction of irrigation and fertilizer treatments also had significant effects on all the soil chemical parameters except organic-C and total-N content of the soils at both sites. Among solute transport properties pore-water velocity, dispersion coefficient and mean solute travel time increased in I₃ compared to I₁ at NBSM site, but the reverse was observed at FSM site.

Asian Australas. J. Biosci. Biotechnol. 2016, 1 (3), 521-532