Soil Chemical Properties of TypicQuartzipsamment in Organic and Conventional Farming System

The field study to evaluate the changes in soil chemical properties of TypicQuartzipsamment has been conducted from conventional to organic farming system in Piauí state, Northeastern Brazil. Three areas were were selected: organic (ORG) and conventional (CNV) farming system with “acerola” (Malpighia glabra L.) and native vegetation (NV). The soil samples were collected in the 0-10, 10-20 and 20-40 cm depths to evaluate soil pH, H+ + Al3+, total organic carbon (TOC), exchangeable K+, Ca2+, Mg2+, available P, cation exchange capacity (CEC) and base saturation (BS). The soil in ORG showed higher pH values, TOC and available P contents than CNV system, in all depths. CEC and BS values in ORG were higher than CNV in the 0-10 and 10-20 cm depths. The agricultural practices in ORG provide high increase in soil pH, TOC and P content.