DESLOCAMENTO VERTICAL DE FÓSFORO EM SOLO ARENOSO COM ADUBAÇÕES CONTINUAS DE ESTERCO, SOB CONDIÇÕES CONTROLADAS

Abstract

The soil fertilization through manure application is the most common form of fertilization in the Family Farming production system, but this application is carried out, in most cases, erroneously, resulting in loss of nutrients and groundwater contamination. This study aimed to evaluate the vertical displacement of P (phosphorus) in a sandy soil fertilized with cattle manure in laboratory conditions. The soil studied was a Regolithic Neosol Eutrophic collected in the municipalities of Remígio, Sitio Lajedo do Tetéu in five depths, 0-10, 10-20, 20-30, 30-40 and 40 -50 cm. Were used the miscible displacement in soil columns with 10 cm length method; 2.56 cm diameter, utilizing peristaltic pump with a flow rate of 3.64 cm3 min-1. The adsorption and desorption parameters were estimated using the Sigma Plot program 10 using nonlinear regression. Through the P elution curves were identified the mechanism of P transport process and determined the hidrodispersive parameters by convective-dispersion models (CDE) through the CXTFIT 2.0 program. The high correlation coefficients obtained from the linearized Langmuir and Fleundlich indicate that adsorption models were significantly able to estimate the adsorption of P in the soil, a loss of more than 1 Kg ha-1 of P was estimated in the deeper layers. The results showed that cattle manure fertilization in sandy soil, offers real risks of groundwater contamination of the region.