Caracterização do solo dos sítios do experimento esecaflor

Abstract

The dry forest experiment (ESECAFLOR), which aims to exclude water from the soil and verify the effects of this stress on soil characteristics and vegetation, is being developed in the Scientific Station Ferreira Penna (Caxiuanã-PA). The objective of the present work is to follow the initial soil surveys before and after the implementation of the experiment. The partial results presented refer to the morphological (color, structure, drainage,), physical (grain size), physical-chemical (pH) and chemical (organic carbon and CO, evolved) characteristics of soils at two ESECAFLOR sites (A and B) and one site where the LBA Project's micrometeorological observation tower is located (T). The soils, classified as Latosol, presented a sequence of A, B, and C horizons. The coloration ranged from dark yellow bruno (10YR) to yellowish red (5YR). The ESECAFLOR sites are sandy and well drained. On the other hand, at the T site the soil is clayey and moderately drained. In general, an inversely proportional variation between organic carbon (C) and pH was observed at depth. The pH values showed little variation with depth and ranged from extremely acidic to strongly acidic. The C contents varied from 4 to 100g/Kg at site A, from 4 to 60g/kg at site B and from 15 to 143g/kg at site T. On the other hand, the average evolved CO contents were higher at site T (8.08mg/g) than those found at sites A (6.60mg/g) and B (5.28mg/g). This shows that the higher nutrient content and constant humidity are contributing to the increased biological activity at site T.