of cellulose based textile fibers utilized in forming the sap fiber blended yarn structure a sample of a dref spun composite core yarn made from staple fibers according to the present invention was produced from a modified hydrophilic polyacrylate polymer blended with conventional 3 denier polyester staple fibers a polyolefin membrane having a porosity of about 120 micron was sonically welded around the composite core yarn utilizing an off line sonic bonding machine this yarn then was tested for water absorption and retention in comparison to testing with a similar size strand cut from a conventional aquamat u2122 100 polyester product it can be observed that although the aquamat u2122 100 polyester takes on a relatively large amount of water initially a significant amount of the trapped water is not retained over time this is because the polyester fibers are actually hydrophobic and the water is only temporarily captured within the interstices of the structure with the present invention however the sap composite core yarn swells and retains a large majority of the water absorbed even after significant time lapse in a second series of tests boxes of sand and topsoil were prepared with composite core yarns of the present invention prepared.