Use of bark and combined paper sludge for the re-vegetation of bark-covered land

Abstract

This study investigated the use of bark and combined paper sludge, poor and rich in nutrients, in order to develop a suitable plant growth substrate and to establish a vegetation cover on bark-covered land. A short-term field experiment was established in Taschereau, Quebec, Canada to: 1- determine a suitable plant growth medium on a bark-covered land; 2- determine which plant mixture should be selected for establishment on this site and 3- determine a fertilization program for one selected plant. By the end of the summer, the best soil cover consisted of 2.5 cm of combined paper sludge on top of 2.5 cm of black bark, which gave good plant appearance, cover, and yield. On this soil cover, the Savoureux mixture (53% perennial grasses and 37% perennial legumes) in combination with birdsfoot trefoil (Lotus corniculatus L.), Lab02 (65% perennial grasses and 35% perennial legumes) in mixture with MR77 (100% perennial grasses), and birdsfoot trefoil in mixture with bromegrass (Bromus inermis L.) gave good vegetation growth and yields. For the birdsfoot trefoil fertilization experiments, and over all soil covers, nitrogen fertilization was not required, but phosphorus and potassium fertilizations should be, respectively, 140 kg P2O5/ha and 160 kg K2O/ha to obtain good plant growth and yield. These first results suggested that combined paper sludge and black bark can be used as topsoil to favor plant establishment on bark-covered land.