Controlled drainage and subirrigation - A water management option to reduce non-point source pollution from agricultural land

摘要

Losses of nutrients from arable land significantly contribute to the eutrophication of lakes and coastal waters. Consequently agricultural nutrient and water management strategies have been emphasized during the last decades. The problem of excessive drainage at certain times of the year in conventional drainage systems (CD) can in many cases be overcome by implementing controlled drainage strategies (CWT). The data for this paper is based on water management projects, at both plot and field scales, which have been carried out in Southern Sweden during the period 2002 to 2005. The studies included water table strategies in which the subsoil was subjected to various degrees of water status at different times of the year by means of controlled drainage system. They were run on one site with small plots and two sites with field scale plots, and each site consisted of one CD plot and three CWT plots.