tailieunhanh - Báo cáo khoa học nông nghiệp " Irrigating rice crops with waste water to reduce environmental pollution from catfish production in the Mekong Delta "

Chất thải từ cá tra thâm canh (Pangasianodon hypophthalmus) nuôi trồng thủy sản 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 xử lý nước thải từ ao nuôi cá da trơn ở sông Mekong Đồng bằng ứng dụng đất cho các lĩnh vực lúa như vậy thể được phục hồi các chất dinh dưỡng của gạo cây trồng như là một thay thế phân bón. Một cuộc khảo sát vào mùa khô năm 2007 các lĩnh vực kết hợp trong năm Giang tỉnh cho thấy có cánh. | Technical Report Irrigating rice crops with waste water to reduce environmental pollution from catfish production in the Mekong Delta 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 Pangasianodon hypophthalmus aquaculture production has become a pollutant of surface waters in the Mekong Delta Vietnam. In the present study the aim was to treat the wastewater 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 survey in the dry season 2007 of paired fields in An Giang Province showed that rice yield in 16 paddies receiving waste from fishpond was 1 t ha higher than in another 16 paddies that did not use wastes. In six field experiments using fishpond waste water for irrigation decreasing fertiliser N by 33 and P and K by 50 had no effect on rice yields. In other cases decreasing N by 40 or P by 50 did not decrease yield. The variation in nutrient composition in waste water among sites and in yield potential and irrigation requirements especially 1 Corresponding author Cuu Long Rice Research Institute O Mon district Cantho city-Vietnam. Phone No 84 710861452. Fax 84 710861457. Email caovanphung@ between wet lower yield potential and lower irrigation requirement and dry seasons may account for the different extent of fertiliser replacement feasible by waste water without decreasing yield. Ten -20 ha of padi land would be required to use the wastewater produced in the dry season from 1 ha of fishponds assuming that only wastewater is used for irrigation. In the early wet season rainfall would prevent wastewater irrigation on some days so that 20-40 ha of padi land may be .