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Fate of Pesticides in Combined Paddy Rice–Fish Pond Farming Systems in Northern Vietnam
Author(s) -
Anyusheva Maria,
Lamers Marc,
La Nguyen,
Nguyen Van Vien,
Streck Thilo
Publication year - 2012
Publication title -
journal of environmental quality
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.888
H-Index - 171
eISSN - 1537-2537
pISSN - 0047-2425
DOI - 10.2134/jeq2011.0066
Subject(s) - pesticide , dimethoate , environmental science , fenitrothion , paddy field , aquaculture , agriculture , population , agronomy , toxicology , biology , fishery , ecology , fish <actinopterygii> , demography , sociology
During the last decades, high population growth and export‐oriented economics in Vietnam have led to a tremendous intensification of rice production, which in turn has significantly increased the amount of pesticides applied in rice cropping systems. Since pesticides are toxic by design, there is a natural concern on the impact of their presence in the environment on human health and environmental quality. The present study was designed to examine the water regime and fate of pesticides (fenitrothion, dimethoate) during two consecutive rice crop seasons in combined paddy rice–fish pond farming systems in northern Vietnam. Major results revealed that 5 and 41% (dimethoate), and 1 and 17% (fenitrothion) of the applied mass of pesticides were lost from the paddy field to the adjacent fish pond during spring and summer crop seasons, respectively. The decrease of pesticide concentration in paddy surface water was very rapid with dissipation half‐life values of 0.3 to 0.8 and 0.2 d for dimethoate and fenitrothion, respectively. Key factors controlling the transport of pesticides were water solubility and paddy water management parameters, such as hydraulic residence time and water holding period. Risk assessment indicates that the exposure to toxic levels of pesticides for aquaculture ( Cyprinus carpio , Daphnia magna ) is significant, at least shortly after pesticide application.