Irrigation with reclaimed water is an important way to deal with water shortage of agricultural production and solve the problem of sewage pollution. The response of crop antioxidant enzyme system is an early-warning ...Irrigation with reclaimed water is an important way to deal with water shortage of agricultural production and solve the problem of sewage pollution. The response of crop antioxidant enzyme system is an early-warning indicator of environmental factors changes. Compared with raw wastewater and used fresh water as controls, this research studied peroxides （POD）, superoxide dismutase （SOD） activities and malondialdehyde （MDA） content in leaves from maize （Zea mays L.） and soybean （Phaseolus vulgaris L.） with pot culture under irrigating with reclaimed water which with secondary and third treatment. The results showed that secondary reclaimed water had some adverse effects on antioxidant system of maize in seedling stage, and the influence decreased in later stage of maize; effect of the third reclaimed water on antioxidant system of maize was not significant. Irrigation with reclaimed water has little influence on antioxidant system of soybean in seedling and reaping stage, but it could bring some oxidative stress in blossom stage. As a result, irrigating maize with second or third reclaimed water is safe to the growth of maize and soybean, but it is suggested that second reclaimed water should not be used in seedling stage of maize and reclaimed water should not be used in the second stage of soybean.展开更多
The phytotoxicity of added copper （Cu） and nickel （Ni） is influenced by soil properties and field aging. However, the differences in the chemical behavior between Cu and Ni are still unclear. Theretbre, this study...The phytotoxicity of added copper （Cu） and nickel （Ni） is influenced by soil properties and field aging. However, the differences in the chemical behavior between Cu and Ni are still unclear. Theretbre, this study was conducted to investigate the extractability of added Cu and Ni in 6-year field experiments, as well as the link with their phytotoxicity. The results showed that the extractability of added Cu decreased by 6.63% （5.10% 7.90%）, 22.5% （20.6e,~~23.9%）, and 6.87% （0~17.9%） on average lbr acidic, neutral, and alkaline soil from 1 to 6 years, although the phytotoxicity of added Cu and Ni did not change significantly from 1 to 6 years in the long term field experiment. Because of dissolution of Cu, when the pH decreased below 7.0, the extractability of Cu in alkaline soil by EDTA at pH 4.0 could not reflect the effects of aging. For Ni, the extractability decreased by 18.1% （10.1e/~33.0%）, 63.0% （59.2% 68.8%）, and 22.0% （12.4% 31.8%） from 1 to 6 years in acidic, neutral, and alkaline soils, respectively, indicating the effects of aging on Ni were greater than on Cu. The sum of ten sequential extractions of Cu and Ni showed that added Cu was more extractable than Ni in neutral and alkaline soil, but similar in acidic soil.展开更多
基金This paper was supported by the National High Technology Research and Development Program of China （863 Program, No. 2006AA100205） and National Natural Science Foundation of China （No. 50679080）
文摘Irrigation with reclaimed water is an important way to deal with water shortage of agricultural production and solve the problem of sewage pollution. The response of crop antioxidant enzyme system is an early-warning indicator of environmental factors changes. Compared with raw wastewater and used fresh water as controls, this research studied peroxides （POD）, superoxide dismutase （SOD） activities and malondialdehyde （MDA） content in leaves from maize （Zea mays L.） and soybean （Phaseolus vulgaris L.） with pot culture under irrigating with reclaimed water which with secondary and third treatment. The results showed that secondary reclaimed water had some adverse effects on antioxidant system of maize in seedling stage, and the influence decreased in later stage of maize; effect of the third reclaimed water on antioxidant system of maize was not significant. Irrigation with reclaimed water has little influence on antioxidant system of soybean in seedling and reaping stage, but it could bring some oxidative stress in blossom stage. As a result, irrigating maize with second or third reclaimed water is safe to the growth of maize and soybean, but it is suggested that second reclaimed water should not be used in seedling stage of maize and reclaimed water should not be used in the second stage of soybean.
文摘The phytotoxicity of added copper （Cu） and nickel （Ni） is influenced by soil properties and field aging. However, the differences in the chemical behavior between Cu and Ni are still unclear. Theretbre, this study was conducted to investigate the extractability of added Cu and Ni in 6-year field experiments, as well as the link with their phytotoxicity. The results showed that the extractability of added Cu decreased by 6.63% （5.10% 7.90%）, 22.5% （20.6e,~~23.9%）, and 6.87% （0~17.9%） on average lbr acidic, neutral, and alkaline soil from 1 to 6 years, although the phytotoxicity of added Cu and Ni did not change significantly from 1 to 6 years in the long term field experiment. Because of dissolution of Cu, when the pH decreased below 7.0, the extractability of Cu in alkaline soil by EDTA at pH 4.0 could not reflect the effects of aging. For Ni, the extractability decreased by 18.1% （10.1e/~33.0%）, 63.0% （59.2% 68.8%）, and 22.0% （12.4% 31.8%） from 1 to 6 years in acidic, neutral, and alkaline soils, respectively, indicating the effects of aging on Ni were greater than on Cu. The sum of ten sequential extractions of Cu and Ni showed that added Cu was more extractable than Ni in neutral and alkaline soil, but similar in acidic soil.
