The plastic suction plates are especially suited for the extraction of soil solution on large areas and its examination on heavy metals and phosphate. Because of their low charged surfaces, plastics are the best materials for these purposes. The filter elements have a tongue and groove system and can be put together to areas of any size. Due to the extraction of soil water over a large area together with low adsorption losses quantitative examinations of solute fluxes are possible. The filter part of the suction plates consists of a porous polyethylene substructure and a hydrophile polyamide membrane filter which is protected against damaging by a cover shield. The standard set comprises: a square plastic porous soil water sampling plate 250 x 250 mm incl. teflon sampling tube, sampling bottle with silicone stopper and a vacuum pump with manometer.