ABSTRACT
The current study has as purpose to evaluate and compare chemical changes in seven areas with different usage time cultivated with papaya in Irrigation Project Baixo, Açú, RN, in relation to native vegetation ‘Caatinga’. For the native forest, twenty single samples were taken; and in each of the five areas cultivated a composite sample was formed from twenty single samples. The studied characteristics were calcium, magnesium, potassium, sodium, phosphorus, pH and EC as well as the heavy metals lead, nickel, cadmium, copper, zinc, manganese and iron. Thus, it was observed that there is an increase in the deviation related to the reference area for phosphorus and pH in all areas and that the use of indices was a very efficient tool in quantifying changes for each index in relation to the native vegetation.
Key words:
soil quality; environmental quality; mathematical model
