Compostos de lodo de esgoto para a produção de mudas de anadenanthera colubrina (vell.) brenan

Abstract

The use of sewage sludge as raw material for forest growing is an alternative for the utilization and disposal of this solid waste. This work aimed at evaluating the use of a substrate based on composted sewage sludge and crushed pruning tree for the production of Anadenanthera colubrina seedlings (monjoleiro) using three different fertilization levels. Seedling growth was then compared to growth on a commercial substrate based on composted Pinus bark and vermiculite. Three levels of fertilization (0; 2.7 and 4 g.dm-3) and three types of substrates were used: commercial substrate, and 3:1 (v:v) or 2:1 (v:v) composted substrate based on aerobic sewage sludge and crushed tree pruning. Seedling height, diameter and aerial dry mass (leaves and branches) were measured. Considering seedlings growth without fertilization, the greatest values for all morphological characteristics were obtained using composted substrate based on sewage sludge. Growth rates in all treatments using 2.7 g.dm-3 of fertilizer, in many cases, can be considered sufficient, showing adequate amounts of nutrients to make up Anadenanthera colubrina seedling nutritional requirements and to promote adequate growth, with economy of the fertilizer.