Relações entre as propriedades químicas e físicas de um solo irrigado com efluente de esgoto tratado.

Abstract

Irrigation with treated sewage effluent (TSE) can be considered as a valuable alternative before the imminent scarcity of the water resources. In this experiment, an oxisol cultivated with corn and sunflower was irrigated during two years with TSE. At the end, some physical properties (saturated hydraulic conductivity-KS, crypto-, micro- and macroporosity, water dispersed clay-WDC) and some chemical properties (Na+, K+, Ca2+, Mg2+, potential acidity) were determined. The correlation analysis reveals the difficulty and the care needed for interpreting theses results. Thus, the Na+, although this ion is known as responsible for alteration in soil physical properties, presented low correlation with them, due to its high mobility in soil. On the opposite, a false correlation between Ca2+ and KS was identified. Correlations among water content, porosity, WDC, Na+ and K+ confirmed the presence of phenomena of aggregates dispersion/expansion and high competition between Na+ and K+.