CRESCIMENTO DE MUDAS DE Sesbania virgata (Cav.) Pers. PLANTADAS EM UMA ÁREA DEGRADADA POR EXTRAÇÃO DE ARGILA

This experiment intended to evaluate the initial growth of Sesbania virgata (Cav.) Pers. (sesbânia) seedlings planted with distinct fertilizers in a degraded area after clay extraction. The seedlings were inoculated with Rhizobium and arbuscular mycorrhizal fungi. The experiment was carried out in a randomized complete-block design. Each experimental unit had 4 repetitions with 16 seedlings. The treatments were: 1. control; 2. “ferkal” (0,6 kg hole-1); 3. urban waste (0,8 kg hole-1); 4. sugar cane filter cake (0,6 kg hole-1) and 5. simple super phosphate (0,1 kg hole-1). Along the first 3 months the rate of surviving plants was evaluated. Height and diameter at the soil level had been bimonthly measured until the tenth month of growth. At this time were also measured the N, P and K nutrient contents of the leaves as well as the biomass production. No difference among the treatments had been observed for these variables. Effects of fertilization on the growth and production of biomass were not found out under the conditions of this study. Lenght and superficial thin root area (diameter larger and smaller than 0,3mm) were evaluated 14 months after planting. Higher values of length and thinner superficial area of the smallest roots were verified in comparison to the larger ones (more than 0,3 mm). Urban waste and sugar cane filter cake stimulated root production.