Modification of some properties of a soil c1assified as Kandiudult ródico were studied. The modifications were produced as consequence of the substitution of native forest by Pinus elliottii in Misiones Province, Argentina.
The experiment design consisted of two treatments: Native forest and Pinus elliottii forestation, each one had twenty plots distributed at random; samples of soil were taken 0-15 cm deep and in each one the following characteristics were determined: texture, bulk density (DA), aggregate stability (EA), pH, effective cation exchange capacity (CICE), organic matter (MO), total nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), exchangeable acidity (Ai), aluminium (Al).
An average difference test was carried out with two independent samples, finding statistical significance in EA, in DA and in MO at levels of 0.01 %; in N at level of 0.04%; CICE at level of 2.11% and Ca at 2.85%. The substitution of native forest by Pinus elliottii produces an increase of DA and the decrease of EA, pH, MO, N, Ca, and CICE. Significant differences were not found among the studied sites for the rest of the analysed variables.