Comportamento hidrodinâmico de solos em cultivos de vazante no semiárido de Pernambuco
Authors: Eduardo Soares de Souza, Antonio Celso Dantas Antonino, André Maciel Netto, Rodolfo Marcondes Silva Souza, Manuella Virginia Salgueiro Gondim, Valmir Felix de Lima, José Romualdo de Sousa Lima, Edevaldo Miguel Alves, Artur Paiva Coutinho, Willames de Albuquerque Soares
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Hydrodynamic behavior of soils in recession agriculture was evaluated through of the soil water characteristic curve θ(h), hydraulic conductivity as a function of the soil water potential K(h), sorptivity S, and characteristic pore radius λm, in two Fluvents soils at the recession emerging zone of Cajueiro and Flocos reservoirs, in Tuparetama, PE. The soil of Cajueiro shows a little transition of texture and dry bulk density, while the soil from Flocos has an evident transition from texture and bulk density with depth. The curves θ(h) were obtained by fitting the model proposed by van Genuchten to field data (obtained with tensiometers and a neutron scattering probe), and to laboratory data (obtained with a Richards pressure chamber). Experiments on the disk infiltrometer (0.08 m diameter base) were performed for obtaining K and S values, at the depths of 0, 0.20, 0.40, 0.60 and 0.80 m, applying four water potentials. The θ(h) curves showed good agreement for potentials ranging from -30 to -10 kPa, indicating the good quality of the experimental data. The soil hydrodynamic heterogeneity in Flocos may be explained by texture and dry bulk density and in Cajueiro this heterogeneity is induced by the pore size distribution. The diameter of the infiltrometer that was used together with the applied pressures, have allowed characterizing the porous matrix of the clay layer of Flocos.