title: Sewage sludge stabilisation and fertiliser value in a silvopastoral system developed with Eucalyptus nitens Maiden in Lugo (Spain).
abstract: Copper (Cu) is one of the heavy metals with highest proportion in sewage sludge. In Europe, sewage sludge should be stabilised before using it as a fertiliser in agriculture. Depending on the stabilisation process, sewage sludge has different Cu contents, and soil Cu incorporation rates. This study was undertaken to examine the effect of fertilisation with different types of sewage sludge (anaerobic, composted, and pelletised) on the concentration of total and available Cu in the soil, the tree growth, the pasture production, and the concentration of Cu in the pasture when compared with control treatments (i.e. no fertilisation and mineral fertilisation) in a silvopastoral system under Eucalyptus nitens Maiden. The results of this experiment show that an improvement of the soil pH increased the incorporation and the mineralisation of the sewage sludge and litter, and therefore, the release of Cu from the soil. Moreover, the concentration of Cu in the pasture and the levels of Cu extracted by the pasture improved when the soil organic matter decreased because the high levels of organic matter in the soil could have formed Cu complex. The composted sewage sludge (COM) increased a) the soil variables studied (pH, total Cu, and available Cu) and b) the Cu extracted by the pasture, both probably due to the higher inputs of cations made with it. In any case, the levels of Cu found in the soil never exceeded the maximums as set by Spanish regulations and did not cause harmful effects on the plants and animals. Therefore, the use of COM as an organic fertiliser should be promoted in silvopastoral systems established in edaphoclimatic conditions similar to this study because COM enhanced the productivity of the system from a viewpoint of the soil and the pasture, without causing any environmental damage.
authors.affiliation: Crop Production Departament, Escuela Politécnica Superior de Lugo, University of Santiago de Compostela; Campus Universitario s/n, 27002 Lugo, Spain. Electronic address: mrosa.mosquera.losada@usc.es.
authors.forename: M R
authors.initials: MR
authors.lastname: Mosquera-Losada
authors.affiliation: Crop Production Departament, Escuela Politécnica Superior de Lugo, University of Santiago de Compostela; Campus Universitario s/n, 27002 Lugo, Spain.
authors.forename: N
authors.initials: N
authors.lastname: Ferreiro-Domínguez
authors.affiliation: Crop Production Departament, Escuela Politécnica Superior de Lugo, University of Santiago de Compostela; Campus Universitario s/n, 27002 Lugo, Spain.
authors.forename: S
authors.initials: S
authors.lastname: Daboussi
authors.affiliation: Crop Production Departament, Escuela Politécnica Superior de Lugo, University of Santiago de Compostela; Campus Universitario s/n, 27002 Lugo, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Rigueiro-Rodríguez
mesh_terms: D000822:Animal Husbandry; D003300:Copper / Q000032:analysis*; D052918:Environmental Restoration and Remediation; D005052:Eucalyptus / Q000187:drug effects* / Q000254:growth & development; D005308:Fertilizers / Q000032:analysis*; D016468:Forestry / Q000379:methods*; D012722:Sewage / Q000032:analysis* / Q000737:chemistry; D012987:Soil / Q000737:chemistry*; D012989:Soil Pollutants / Q000032:analysis*; D013030:Spain
chemical_list: D005308:Fertilizers; D012722:Sewage; D012987:Soil; D012989:Soil Pollutants; D003300:Copper
keywords: Agroforestry; Anaerobic; And pelletised; Composted; Copper