USING SUBIRRIGATION TO MAINTAIN SOIL-MOISTURE CONTENT IN GREENHOUSE EXPERIMENTS

In greenhouse studies, overhead watering or subsurface irrigating soil can cause fluctuating moisture content, as can treatments such as sur face application of residue used in cover crop research. This paper in troduces a method of capillary mat subirrigation that maintained soil moisture at about field capacity for 16 d while no moisture could be d etected after 6 d in soil placed under similar conditions that was not irrigated. In another study, subirrigation eliminated differences in soil moisture due to the presence of surface-applied residue and moist ure supplied by hand watering from overhead was apparently removed fro m subirrigated treatments, which never differed in soil moisture conte nt.