Análise física do solo em áreas degradadas sob condições de pousio e adubação orgânica no semiárido cearense.

Abstract

The current scenario of an environment in the process of desertification is not very desirable for a population experiencing this situation directly. In Irauçuba, in the north-central sertão, and in the microregion of Sobral, both in the State of Ceará, the problem of desertification has had an increasingly critical effect on people's lives, especially in rural areas. As such, two chapters on this theme will be presented. The first chapter is a broad report on the situation in Irauçuba, including the implications of desertification on cultural, social, economic and environmental factors. In the second chapter, the aim of the research is to evaluate the application of organic fertilisers on the physical quality of the soil by means of indicators, in a degraded area in the process of desertification. Disturbed and undisturbed soil samples were collected to determine the following: infiltration, hydraulic conductivity, soil water characteristic curve (SWCC), S-index, air permeability and organic carbon. In the present study, a completely randomised design (CRD) was used, with three replications and eight treatments: legumes, organic fertilisers and mulch, plus a negative control (with no fertiliser) and a positive control (fallow). In the statistical analysis, the mean values were compared by F-test at 1% probability using orthogonal contrasts. The areas of fallow and the treatments based on simple organic input resulted in an improvement in the physical quality of the soil for the S-index only; for the other variables, no positive effect was detected on the pore geometry of the soil.