Avaliação de propriedades físico-químicas no solo e agrotóxicos sob diferentes usos e ocupação

Abstract

Soil is a complex natural resource that comprises one of the densest and most biodiverse habitats on planet Earth. Anthropogenic activity through land use and occupation alters its physical-chemical properties, making it more susceptible to environmental contamination, causing degradation of quality and interfering with agricultural productivity and food security. This work aimed to carry out an assessment of the physical-chemical properties and emerging environmental contaminants (pesticides) under different uses and occupation of the soil around deep water wells for human consumption. Soil sampling was carried out in two sampling campaigns (October and November/2021 and January/2022) on twenty-one private rural properties with different uses and occupation: (native field, irrigated rice and annual crops (corn/soy/wheat )). Physical variables such as texture, granulometry (sand, silt and clay) were determined, as well as chemical analysis of organic matter, hydrogen potential (1:1) and chemical elements aluminum, boron, calcium, cadmium, cobalt, copper , chromium, sulfur, iron, phosphorus, magnesium, manganese, potassium, sodium and zinc. The results of the chemical analyzes relevant to the chemical elements were compared with current Brazilian legislation (national and state). The chemical elements of copper and zinc are in accordance with legislation. Cadmium, cobalt and chromium, however, presented values that differed from those established by legislation. The elements aluminum, boron, calcium, sulfur, iron, phosphorus, magnesium, manganese, potassium and sodium are not covered by current legislation. The highest mean element values were found in the uses and occupation of irrigated rice and annual crops. For emerging environmental contaminants in the use and occupation of native fields, there was no detection of active pesticide ingredients in the sample campaigns evaluated. For the use and occupation of irrigated rice, active ingredients of pesticides were detected in the first collection period and for annual crops in the two collection periods, active ingredients of pesticides were detected, with emphasis on the active ingredient of the insecticide imidacloprid. However, these detected emerging environmental contaminants are not covered by current legislation. Finally, it can be concluded that the uses and occupation of the soil around the study sites through human activity influence the physical-chemical properties of the soil, as well as factors related to the content of chemical elements and the depth analyzed, which greater attention/care must be given to implementing recommendations for each agricultural crop, advocating sustainable and correct management in the pursuit of preserving soil quality and food security.