Análise do ciclo da cultura de cana-de-açúcar e seus possíveis impactos quanto ao uso de agrotóxicos: estudo de caso em uma usina sucroalcooleira no município de Santa Rita-PB

Abstract

Brazil is the largest sugar cane producer in the world, standing out mainly by the startup of the National Alcohol Program (Proálcool) in the mid 70’s, and combined with this growth, there has been an increase of the use of pesticides in that culture. Thus, this study aimed to analyze the sugarcane cycle on a sugarcane mill in the city of Santa Rita-PB and investigate the possible environment impacts resulting from the use of pesticides in the sugar cane. Initially the identification of the vegetative cycle of the sugar cane was carried out based on the survey of the pesticides used by the Plant. For this, on-site visits, interviews, and photographic records were carried out. Subsequently, the environmental impacts were identified based on two conditions: the first one was through the analysis of pesticide residues in four (04) sugarcane samples corresponding to the phases of the vegetative cycle. All samples were analyzed by LABTOX / ITEP, following the Maximum Residue Limit (MRLs) allowed by the National Sanitary Surveillance Agency (ANVISA). The second situation was by estimating the potential risk of groundwater contamination (Criterion EPA and GUS Index) and surface water (GOSS method) based on the physico-chemical properties analysis of the active ingredients from the investigated compounds. As a result, it was identified in the study area the use of twenty five active principles present in different trademarks, being herbicidal the predominant class, corresponding to 80% of the investigated compounds. The analysis of pesticide residues in the sugar cane had their satisfactory opinions, not containing the presence of the active investigation principles.The physico-chemical properties of the active ingredients: 2.4 D, Glyphosate, Picloram and Hexazinone, stood out for having a greater agreement on the transport trend of its molecules by water. Regarding the estimation of contamination of groundwater, it was observed that most of the compounds evaluated by both methods have the potential contamination trend (CP), counting a total of 13 active ingredients (52%) of the total evaluated. It has been verified that the majority of the compounds have a greater tendency to transport their molecules dissolved in water and transported by means of rainwater transport. Thus, it can be concluded that the analysis of pesticide data and their physicochemical characteristics, enabled the analysis of the possible environmental impacts in the cultivation of sugarcane and water resources, and also the need for implementation of environmental monitoring programs.