DISTRIBUIÇÃO DE POROS POR TAMANHO E SUA RELAÇÃO COM OS PARÂMETROS DE AJUSTES DA CURVA DE RETENÇÃO DE ÁGUA NO SOLO

Abstract

The pore distribution by size influences the gases dynamics and the soil solutes, besides acting on the development of the root system of plants. However, it verifies that in sandy soils the irregular distribution of sand particles can modify the pore distribution and their hydro-physical functioning. Considering this, the objective of this work was to analyze the relationship between the pore distribution in the soil by size and the adjustment parameters of the water retention curve in the soil (α, n) in a Planosols Haplic under management of conservationist production in the Agreste region of Paraíba state. Soil samples with undisturbed structure were collected in the soil under a system integrating crops, livestock and forests in the layers of 0.00-0.10 and 0.10-0.20 m, in Alagoinha, Paraíba state. The granulometric analysis was carried out with sand fractionation in size classes. Also, the samples were submitted to potentials -6, -10, -33, -100, -300, -500, -1000 and -1500 kPa, to determination the water retention curve in the soil and pore distribution by size. The Planosols showed a predominance of the sand fraction in the medium and fine fractions. The pore distribution was heterogeneous according to the sand content. It was concluded that the pores distribution by size presented a positive and significant correlation with the estimated values of the adjustment parameters of the water retention curve in the soil (n) and (α).