The study site is located at Fazenda Guanabara in
Paranapoema (22º43’S, 57º07’W) in the northwestern
region of the Paraná state of Brazil. The location is 400
m above sea level, and the climate is classified as humid
subtropical (Cfa according to the Köppen classification,
LUTGENS; TARBUCK, 2004); the average annual
temperature is 22ºC, and the total annual precipitation
is 1500 mm. The soil at this site was classified as Oxisol
according to the United States Department of
Agriculture (USDA) Soil Taxonomy (Latossolo
Vermelho in the Brazilian Soil Classification System).
The soil has a loamy sand texture (85% sand, 1% silt
and 14% clay) and a pH (CaCl2) of 4.0 at a 0-20 cm
depth.