Abstract: This invention relates to a mulch having a preprogrammed biodegradability comprising at least two different layers of biodegradable polymer coated onto a sheet of a cellulosic material, one of these layers being a layer of polylactide. The mulch is particularly useful to control weeds in agriculture, horticulture, and forestry industries. The biodegradability of the mulch can further be preprogrammed according to the type of soil, the climatological zone, and the specific applications wherefore it is intended to be used. The present invention is also directed to methods for preparing and using the multilayer coated mulch.

Abstract: The mulch comprises a sheet of paper having a thickness between 2 and 4 mils and a basis weight between about 40 g/m.sup.2 and 60 g/m.sup.2. The sheet has at least one face coated with a layer of polylactide, which is used in an amount such that it weighs between about 2 g/m.sup.2 and 15 g/m.sup.2. The preparation is carried out by depositing on the sheet an amount of a hot extruded liquid layer of polylactide such that when it solidifies, it weighs between about 2 g/m.sup.2 and 15 g/m.sup.2, and allowing the layer to solidify and adhere to the sheet, whereby forming the mulch.