Effect of crusting on the physical and hydraulic properties of a soil cropped with Castor beans (Ricinus communis L.) in the northeastern region of Brazil

E.S. Souza (1) , A.C.D. Antonino (2) , R.J. Heck (3) , S.M.G.L. Montenegro (4) , J.R.S. Lima (5) , E.V.S.B. Sampaio , Rafaël Angulo-Jaramillo (6) , M. Vauclin (7)

1 Unidade Academica de Serra Talhada
2 Departamento de Energia Nuclear
3 School of Environmental Sciences
4 Departamento de Engenharia Civil
5 Unidade Academica de Garanhum
6 Équipe 5 - Impacts des Polluants sur les Écosystèmes
7 Transpore

Crusts are responsible for the reduction of infiltration into soil and increase in runoff during rainfall and irrigation. In a four-ha castor bean field, seven plots (about 1 m(2) each) with visible soil crusts, and seven without crust, were marked and measurements were made of hydraulic conductivity (K-s), sorptivity (S), initial (theta(o)) and final (theta(s)) volumetric water content, sheer strength (tau), as well as grain yield. The non-crusted soils were three times more conductive (0.085 +/- 0.014 mm s(-1) vs 0.025 +/- 0.008 mm s(-1)) and castor beans yields almost three times higher (1.53 +/- 0.43 t ha(-1) vs 0.62 +/- 0.21 t ha(-1)) than in the crusted soils, but presented half of their sheer strength (54.00 +/- 9.01 kPa vs 107.14 +/- 17.70 kPa). The soil did not differ in their characteristic pore radius (0.17 +/- 0.05 mm vs 0.14 +/- 0.03 mm), nor initial and final volumetric water contents (0.04 +/- 0.02 vs 0.05 +/- 0.01 cm(3) cm(-3); 0.43 +/- 0.02 vs 0.40 +/- 0.02 cm(3) cm(-3)). Despite lower mean characteristic pore size Am values, the non-crusted soils were more conductive, than crusted soils, due to their five times higher hydraulically active pore density. (C) 2014 Published by Elsevier B.V.

Mots clés: Beerkan method; Infiltration; Saturated hydraulic conductivity; Sorptivity; Shear strength

Domaines: Biodiversité et Ecologie

E.S. Souza, A.C.D. Antonino, R.J. Heck, S.M.G.L. Montenegro, J.R.S. Lima, et al.. Effect of crusting on the physical and hydraulic properties of a soil cropped with Castor beans (Ricinus communis L.) in the northeastern region of Brazil. Soil and Tillage Research, 2014, 141, pp.55-61. ⟨10.1016/j.still.2014.04.004⟩. ⟨hal-01113145⟩