%0 Journal Article
%T Applying Sewage Sludge to Eucalyptus grandis Plantations: Effects on Biomass Production and Nutrient Cycling through Litterfall
%A Paulo Henrique M¨¹ller da Silva
%A Fabio Poggiani
%A Jean Paul Laclau
%J Applied and Environmental Soil Science
%D 2011
%I Hindawi Publishing Corporation
%R 10.1155/2011/710614
%X In most Brazilian cities sewage sludge is dumped into sanitary landfills, even though its use in forest plantations as a fertilizer and soil conditioner might be an interesting option. Sewage sludge applications might reduce the amounts of mineral fertilizers needed to sustain the productivity on infertile tropical soils. However, sewage sludge must be applied with care to crops to avoid soil and water pollution. The aim of our study was to assess the effects of dry and wet sewage sludges on the growth and nutrient cycling of Eucalyptus grandis plantations established on the most common soil type for Brazilian eucalypt plantations. Biomass production and nutrient cycling were studied over a 36-month period in a complete randomized block design. Four experimental treatments were compared: wet sewage sludge, dry sludge, mineral fertilizer, and no fertilizer applications. The two types of sludges as well as mineral fertilizer increased significantly the biomass of Eucalyptus trees. Wood biomass productions 36 months after planting were similar in the sewage sludge and mineral fertilization treatments (about 80£¿tons£¿ha£¿1) and 86% higher than in the control treatment. Sewage sludge application also affected positively leaf litter production and significantly increased nutrient transfer among the components of the ecosystem. 1. Introduction Sewage sludge resulting from the treatment of urban liquid residue, channeled to treatment stations through the sewage system, is a residue rich in organic matter. This sludge corresponds to only 1% of the volume of sewage waste, but the treatment and final disposal represents 20 to 40% of the operational costs of a treatment station [1]. Several alternatives exist for disposing of the sludge produced in sewage treatment (solid fraction), such as dumping in sanitary landfills or incineration. The solid fraction of sewage sludge can also be applied as fertilizer in agroecosystems, although it must be used very carefully in order to reduce the risks of health-related problems for the population, damage to the environment, or financial loss to farmers [2]. Applying organic matter at the soil surface to improve its fertility is a traditional practice. Sewage sludge use in agricultural production systems has become an interesting alternative to discarding it, as it may increase overall crop production [3]. Risks associated with sludge application in forest plantations are lower than in agriculture, since tropical Eucalyptus plantations are usually managed to produce fire wood, charcoal, boards, or pulp and paper, and the final
%U http://www.hindawi.com/journals/aess/2011/710614/