Disponibilidade de água no solo em sistemas silvipastoril com eucalipto em renque e pastagem

Abstract

This work aimed to evaluate the water in Typic Paleudult with loam layer (0-20 cm) under sandy loam loam layer (21-100 cm) in silvopastoral and pasture systems in Paranavaí, northwest of Paraná, Brazil. Twelve gravimetric determinations of water in the work were carried out in 2010 and 2011, from 24 to 33 months after planting grass with rank of double rows of eucalyptus (3 m x 2 m) spaced 21 m. Disturbed and undisturbed soil samples were collected in layers of 20 cm to a depth of 100 cm, 2.5, 5 and 10 m from the level terrace in silvopastoral systems with eucalyptus in rank of 8 to 11 m height (Eucalyptus grandis) and pasture (Cynodon nlemfuensis). Undisturbed soil samples were collected with three replicates to determine field capacity, wilting point and bulk density. The gravimetric water data were compared between the layers of the silvopastoral and pasture systems by test confidence interval of the mean (P<0.05). In silvopastoral system, water availability in the soil decreases to 2.5 m from the rank of eucalyptus and in the profile layer of sandy loam (21-80 cm) from the 10.0 m of eucalyptus rank. The availability of soil water in the surface layer increases with the distance of the loam layer (0-20 cm) equivalent to distance the height of the rank of eucalyptus.