The effect of lime admixture to trench backfill on chemical composition of drainage water

Abstract

The field studies on the impact of lime admixture into trench backfill on the chemical composition of drainage water were conducted in a site located in southwestern Lithuania. Heavy-textured clay loam soils were drained by a composite drainage system. To improve water permeability, drainage trenches were backfilled with soil mixed with 0.6% CaO. Results of nine-year studies (1999–2007) on water quality are reported in this paper. Hydrocarbonates and calcium ions are prevailing in drainage outflow. The significant differences between potassium, chlorides, sulphates and phosphate concentrations in control drainage outflow and the treatments with lime were estimated. The improved drainage trench backfill permeability does not increase nitrate leaching to drainage water.