Contaminação Por Nitrogênio E Fósforo De Águas Destinadas Ao Consumo Humano Em Região Com Intensa Atividade Suinícola

Abstract

A atividade suinícola na Região Sul do Brasil, é desenvolvida em pequenas propriedades, com passivo ambiental relacionados aos dejetos. Nesse sentido, a aplicação de dejetos em áreas agricultáveis, é uma prática comum com riscos potenciais de contaminação, para o solo e a água. Nesse sentido, o objetivo do presente trabalho é avaliar a contaminação por nitrogênio e fósforo de fontes de água destinadas ao consumo humano em região com intensa atividade suinícola no estado de Santa Catarina. Para isso, foram realizadas coletas de água, em poços de abastecimento, em propriedades suinícolas no período de 2015 a 2016, no município de Braço do Norte/SC, além de uma coleta de solo em dezembro/2015. Nas amostras de água foram determinados os teores de NH4+, NO3- e formas de P, no solo os teores de N mineral e P disponível. A contaminação dos poços de abastecimento por N aconteceu em duas coletas. Em relação ao P, todos os pontos avaliados apresentam-se contaminados, acelerando a eutrofização. Além disso, há estreita relação entre os teores de P no solo com os teores observados na água, indicando que o monitoramento dos teores de P no solo pode ser um excelente indicativo de contaminação de mananciais hídricos.

Use of Swine Manure in Agriculture in Southern Brazil: Fertility or Potential Contamination?

“…These measures prevent or delay nutrients accumulation in soil and its losses, whether through volatilization (NH 3 ), percolation, or runoff. The absence of measures and monitoring of applications can compromise the quality of water resources present in the swine units, as observed by the studies by Cadoná et al [23] and Loss et al [41]. In the first study, these authors observed in the supply wells of four swine units located in Braço do Norte, SC, an increase in N and P concentrations of in the water.…”

“…However, in these conditions with high SM application the fertilizer efficiency index is reduced, promoting greater addition of nutrients in the soil, but with less use by the crops [26]. Consequently, there is a greater accumulation of nutrients in the soil and greater potential for soil pollution and surface and subsurface water resources through losses from runoff and leaching, respectively [5,23,[38][39][40][41][42]. In terms of runoff losses, the volume of the runoff and the amount of nutrients added to the soil (high doses of manure) are mainly responsible for the increase in losses.…”

“…However, SM also has factors limiting its use, such as its variable concentration of nutrients and unbalanced to the needs of the plants, which can compromise the quality and functionality of the environment when excessive and/or continuous fertilization is carried out in the same areas [13][14][15][16][17]. The main concerns raised by researchers, and according to the publications of international academic society, are related to the phosphorus (P) and heavy metals, such as copper (Cu) and zinc (Zn), accumulation, availability, and losses in areas submitted a long history of applications [3,[18][19][20][21][22][23]. The results of the studies developed to emphasize the importance of adopting technical criteria for the use of SM in agricultural areas, proposing limits of doses used, applications based on soil attributes and composition of manure, the recommendation for crops, determination of limiting elements for the applied dose (mainly P), supplementation of the application of SM with chemical fertilizers and adequate treatments for the storage and stabilization of waste, for example [10,17,24,25].…”