Impacto ambiental do tempo de cultivo na fertilidade química de um argissolo em Mossoró-RN.

Abstract

This work was accomplished with the objective of evaluating impacts on the chemical attributes provoked by the use and handling in a Haplusdalf, cultivated with melon. The selection of the areas was made being taken in consideration four times of use, being an area of native and areas with 2, 2,5 and 3 years of cultivation. In each area it was made the collection of soil samples in 10 aleatory points and 3 depths (0-20, 20-40 and 40-60 cm). Followed being the methodologies recommended by EMBRAPA (1997), the following analyses were accomplished: pH, phosphorus, potassium, calcium, magnesium, sodium, aluminum, hydrogen, organic carbon and electric conductivity. With base in the results the tenors of organic matter were calculated, sum of bases, saturation for bases, for sodium and aluminum. The data were submitted to variance analyzes for the test F, considering a factorial 4 x 3 (4 times of use and 3 depths), with 3 repetitions. The cultivation time influenced all the analyzed variables, except magnesium. Just the pH, electric conductivity, organic matter, phosphorus and potassium presented significant alteration in the soil layers studied. With the current practices of handling adopted in the farm, there are not imminent risks of soil degradation.