Acumulação de nutrientes e metais pesados em solo, água e hortaliças em áreas cultivadas com olerícolas no Agreste de Pernambuco.

Abstract

Increasing world population elevates the demand for food. Then, it's a constant challenge to ensure food with quantity and quality appropriate. The management of soil fertility using fertilizers and controlling pests and weeds are necessary strategies for maintaining or increasing agricultural production. Agrochemicals are anthropogenic sources potentially polluting the environment, both the defensive as the mineral and organic fertilizers and agricultural lime, may contain heavy metals such as impurities in their composition. The horticulture stands out as an activity that uses many inputs, with frequent application of pesticides and fertilizers. Thus this study aimed to determine the concentrations of nutrients and heavy metals in soils, water sources and vegetables in areas under different land uses in the Sao Felix Camocim city, Pernambuco State, Brasil, evaluating the risk of environmental contamination. Soil samples were collected in the rows in the upper, middle and bottom of the hill farming areas, and in the forest areas, at three depths (0-10, 10-30 and 30-60 cm). Monthly, were collected 200 mL of water dams that supply the area under cultivation, and plant samples of Tomato, Eggplant, Pepper, Zucchini and Chard. Variables were subjected to analysis of variance and Tukey test at 5% probability level. Applied the t test ( P < 0,05) for medium aiming paired comparisons between content of heavy metals in cultivated areas and forest, besides Pearson correlations (P<0,05; 0,01). The fertility of soils resulting from cultivation with vegetables has changed in relation to forest areas (reference).The management of the phosphate fertilizations in areas cultivade with vegetables caused increase in levels of available P in the soil, causing pollution of water bodies water (dams); The levels of NPK and pH of the water dams was influenced by rainfall, with reduction of soil pH and P levels, and increasing concentrations of NO32- and K, The phosphate fertilization appeared to be the main entry of Cd in the soil as a contaminant of fertilizers, and was found accumulation of Cd, Cu, Mn and Zn in the first depth of soil.Rainfall had a greater influence on the concentration of Pb and moderate influence on concentrations of Cd and Ni was not detected the presence of Cu, Mn and Zn in surface water and in the well.