关键词: 三江平原, 沼泽湿地, 水分生态, 阈值

Abstract: A pot experiment was conducted to study the effects of applying controlled-release compound fertilizer on the flue-cured tobacco leaf physiological properties and nitrogen, phosphorus and potassium contents. Increasing the application rate of controlled-release compound fertilizer largely improved the tobacco leaf chlorophyll content in whole growth period, the carotenoids content and superoxide dismutase activity at spherical plant-topping stag, and the asorbic
acid content and peroxidase activity at fast growing-mature stage. In the meantime, the leaf nitrogen, phosphorus and potassium contents also showed an increasing trend. On the contrary, increasing the application rate of controlled-release compound fertilizer markedly decreased the leaf carotenoids content at mature stage, the malondialdehyde and ascorbic acid contents at spherical plant stage, the glutathione content at spherical plant-fast growing stage, and the production rate of superoxide anion free radicals (O^-.₂). To increase the application rate of controlled-release compound fertilizer could not only improve the antioxidant ability of flue-cured tobacco, but also promote the accumulation of nitrogen, phosphorus, and potassium in leaf.

Key words: Sanjiang Plain Wetland, Water Ecology, Threshold