Characterization of a Brazilian clayey soil submitted to conventional and no-tillage management practices using pore size distribution analysis

In this paper is presented the use of soil water retention curves (SWRC) to investigate modifications in pore size distribution (PSD) of a Rhodic Ferralsol submitted to two different long term management practices: no-tillage (NT) and conventional tillage (CT). Soils from both treatments were investigated in 3 different depths, 0–10, 10–20, and 20–30 cm and matric potential values that varied from 0 to −780 kPa. The obtained results showed trimodal PSDs for both treatments, indicating well structured soils. The obtained results suggested that soil under conventional tillage CT and no-tillage NT: (a) first, have modified their structure depending on the treatment they were submitted; (b) second, have their macroporosity reduced to larger depths; and (c) third, have their microporosity largely altered, mainly at the surface, presenting the soil under NT a large microporosity for all investigated depths.