Crescimento de plântulas de jurema preta (Mimosa tenuiflora (Wild) poiret) em solos de áreas degradadas da caatinga.

Abstract

The semiarid region of Northeast Brazil presents serious problems of degradation caused by extractivism of its natural resources and indiscriminate land use for agriculture and cattle raising. This work studied the initial growth of jurema preta (Mimosa tenuiflora (Willd) Poiret) plantules in soils with different levels of degradation. Soil from areas with different levels of degradation was collected, analyzed and distributed in plastic recipients (PET bottles), where two plantules were left growing under greenhouse conditions during 62 days. Data on germination, time for cotyledon loss, plantule height and diameter, and root:shoot biomass ratio were collected and analyzed. Plantules in soil from area 2 with a recovering jurema preta tree cover and protected from grazing in the last five years showed to be higher than plantules in soils from areas 1 and 3 with fewer trees and overgrazed or recently protected from sheep and goat grazing. However, no root:shoot biomass ratio was detected between areas. The observed growth of jurema preta plantules in degraded soils corroborates previous reports of adaptation of this species to harsh environments, and justifies the need of further works on plantules growth of pioneer species in degraded Caatinga sites.