Seedling production of Tectona grandis on substrates formulated with biosolids

The industrial and urban waste can be used as a source of nutrients to contribute not only to reduce the cost of seedling production but also to reduce or solve environmental problems. This study aimed to evaluate the use of sewage sludge as substrate on the production of seedlings of Tectona grandis. Seedlings were grown in tubes with a volumetric capacity of 280 cm³, on substrates formulated with biosolids (BIO) associated with rice hulls (CAC) or shredded coconut fiber (FC) in proportions 80:20, 60:40, 40 60, 20:80 (v:v), and also with 100% of BIO, a total of nine treatment submitted to the comparison of control treatment (commercial substrate). The formed substrates were subjected to chemical and physical analysis. Ninety days after the sub culturing, the following biometrics characteristics were analyzed: shoot height, stem diameter, dry weight of shoot and root and Dickson quality index. The results indicated that the seedlings grown on substrates formulated with BIO and CAC showed the highest average height and shoot dry mass, while those produced with BIO and FC showed the highest average collar diameter. For the production of seedlings of Tectona grandis it is advised to use a substrate with proportions of 60 or 80% of biosolids when associated with coconut fiber, and 80% of biosolids when associated with rice hulls.