Chất thải từ cá da trơn thâm canh nuôi trồng thủy sản sản xuất ĐÃ Trở thành một chất gây ô nhiễm nước mặt ở Đồng bằng sông Cửu Long, Việt Nam. Trong nghiên cứu này, mục đích là để điều trị các chất thải rắn từ ao cá tra ở đồng bằng sông Cửu Long bằng cách ứng dụng đất cho các lĩnh vực lúa để thể được phục hồi các chất dinh dưỡng của cây lúa như là một thay thế phân bón. Một thí nghiệm lĩnh vực WS mùa mưa bắt đầu trong 2007and Tiếp tục 6. | Final Nutrient recovery by rice crops as a treatment for aquaculture solid waste crop yield nutrient status and nutrient budgets Cao van Phung1 Nguyen be Phuc2 Tran kim Hoang2 and Bell . 3 1. Cuu Long Rice Research Institute O Mon Cantho Province Vietnam. Email caovanphung@ 2. An Giang University Long Xuyen An Giang Province Vietnam 3. School of Environmental Science Murdoch University Murdoch 6150 Australia. Abstract Waste from intensive catfish aquaculture production has become a pollutant of surface waters in the Mekong Delta Vietnam. In the present study the aim was to treat the solid waste from catfish ponds in the Mekong Delta by land application to padi fields so that the nutrients could be recovered by rice crops as a fertilizer substitute. A field experiment was commenced in the wet season 2007and continued for 6 consecutive rice crops using three doses of solid wastes 1 2 and 3 tonne ha in combination with 1 3 or 2 3 of the recommended inorganic fertiliser rate 60N-17P-24K in wet season and ha in the dry season in kg ha . Rice yields were generally similar in all treatments in each of the 6 consecutive crops except that wet season yields declined by with 1 3rd the fertiliser dose with only 1 t of solid waste. Moreover with 3 t of solid waste ha 1 3rd fertiliser dose gave higher yields in the dry season than with 2 3rd dose. With straw removal generally N and K balances were positive in the wet season when yields were low but negative in the dry season. With straw retention all K balances were strongly positive but N balances were only positive with the higher solid waste and N fertiliser rates. Phosphorus balances were always strongly positive. Mean levels of organic C N available P K and Zn increased in soils over the course of 6 rice crops. These results suggest that the fishpond solid waste replaced 1 3 to 2 3 of the fertiliser normally applied 1 Corresponding author Cuu Long Rice Research Institute O Mon district Cantho .
