Least limiting water range and critical density of a cohesive Yellow Oxisol under different land uses in the Tabuleiro Costeiro ecosystem

ABSTRACT

The impacts of the use and management on soil physical quality have been quantified using the least limiting water range and the critical density of the soil. The critical soil bulk density obtained by the least limiting water range (LLWR) assists in making decisions on the management conditions adopted or to be adopted in certain soil. This study aimed to determine the LLWR and the critical soil bulk density of a cohesive Oxisoil from Coastal Tablelands Reconcavo of Bahia subjected to different uses and soil management. We selected three areas on typical cohesive soil, subjected to the following uses and management: native forest (Mata Atlântica), Brachiaria decumbens Stapf in a state of degradation and sugar cane, with subsoiling at planting. Forty samples, for each area, were taken with undisturbed in the central portion of each horizon (A and AB). In the area cultivated with sugarcane, the sample collection was done in the rows. The LLWR in the A horizon of the forest and the sugar cane were similar, and both were greater than the pasture on the horizon AB. The LLWR for cane sugar was higher than the forest and that this increased for grazing. Horizons A and Ap presented higher critical density values than AB for all evaluated uses. The use that showed values of bulk density greater than the critical density was pasture.

Key words:
soil physical quality; penetration resistance; critical density