Growth of eucalyptus seedlings in soil with application of tannery sludge

Abstract

Tannery sludge is the residue from bovine leather processing, contains essential nutrients for plants and has the potential to be used as fertilizer in the forestry sector. However, despite its potential, due to the presence of toxic elements, such as chromium, chemical concentrations for its standard application needs to be defined In this context, the present study evaluated the effects of different tannery sludge concentrations on eucalyptus seedlings. We used four different concentrations of tannery sludge (0.1; 1; 10 and 50%) and one control (without sludge application) The seedlings of Eucalyptus grandis x Eucalyptus urophylla hybrids, clone I144 with 30 days, were transplanted to the recipients, where they remained for 45 days. After this period, we evaluated the following resposnse variables: plant height, stem diameter, number of leaves, root length, shoot and root dry mass, pH, conductivity and foliar analysis of Nitrogen. The increasing tannery sludge concentration in the soil caused an increase in pH and electrical conductivity, whilst eucalyptus seedlings showed lower growth and development in 10 and 50% of sludge concentrations. The use of tannery sludge in the soil increased nitrogen availability to the plants, tought at low concentrations (0.1 and 1.0%), root growth and seedlings height were similar to the observed in the control. An application of 10% sludge is recommended to avoid adverse effects from soil salinization on plants.