造纸废水灌溉对黄河三角洲盐碱地土壤酶活性的影响

The influence of irrigation with paper mill effluent on enzyme activity in the saline-alkaline lands of Yellow River Delta

造纸废水含有大量有机营养物质,经生物塘处理后灌溉退化滨海盐碱地可以有效改善土壤化学性质。分析了不同灌溉方式对土壤脲酶、磷酸酶、脱氢酶活性的影响。结果表明:在废水灌溉、清污轮灌和清水灌溉3种处理下,棉田土壤的脲酶、磷酸酶和脱氢酶活性均有显著提高;同样,清污轮灌模式下,轻度、中度及重度盐碱化土壤的脲酶、磷酸酶和脱氢酶活性也均有较显著的提高。较之棉田土壤和轻度盐碱化土壤,中度和重度盐碱化土壤酶活性的提高更为显著,具体表现为,与对照相比,中度盐碱化土壤的脲酶、磷酸酶以及脱氢酶活性分别提高了44.7%、15.6%、12.4%,重度盐碱化土壤分别提高了82.3%、55.1%、32.0%。研究证明造纸废水灌溉不但可以提升退化盐碱地的土壤肥力,还可以显著提高退化盐碱地的土壤酶活性。

Paper mill effluent contains a lot of organic matter,which can be used to improve the chemical properties of degraded coastal saline-alkaline lands after biological pond treatment.At the same time,the increase of soil organic matter after irrigation provided a lot of carbon source for microbes,the microbes have grewed with using these carbon souce,which increase the enzyme activity.The soil enzyme activity and soil fertility also has certain correlation.The urease activity is related to the amount of substrate microorganisms,organic matter and total nitrogen,the higher of the soil nitrogen content,the better of the urease activity.The high low of phosphatase activity and dehydrogenase activity are related to the high low of the amount of the soil organic matter.The influence on soil enzyme activity under different irrigation modes was further analyzed.The results showed that the activities of urease,phosphatase,and dehydrogenase in cotton field soil were significantly increased under the three irrigation modes of sewage irrigation,feculence-clearing rotation irrigation,and fresh water irrigation.Similarly,under the treatment of feculence-clearing rotation irrigation,the activities of urease,phosphatase,and dehydrogenase in slight,moderate and severe salinization soils were also significantly increased.Specifically,compared with the cotton field and slight saline soils,the enzyme activities were increased more significantly in the moderate and severe saline soils.That is,compared with the control group,the activities of urease,phosphatase,and dehydrogenase were enhanced by 44.7%,15.6%,and 12.4%,respectively,in the moderate saline soil;and by 44.7%,15.6%,and 12.4%,respectively,in the severe saline soil.The average activities of the three enzymes in the cotton soil were the highest with sewage water irrigation.The activities of urease,phosphatase,and dehydrogenase under the sewage water irrigation mode were 1.23,1.05,1.39 times as many as those under the feculence-clearing rotation irrigation mode separately.Under the feculence-clearing rotation irrigation,the average activities of the three enzymes in slight,moderate and severe saline soils were the highest.In the slight saline soil,the activities of urease,phosphatase,and dehydrogenase under the feculence-clearing rotation irrigation mode were 1.09,1.08,0.97 times as many as those under the sewage water irrigation mode separately.In the moderate saline soil,the activities of urease,phosphatase,and dehydrogenase under the feculence-clearing rotation irrigation mode were 1.12,1.07,1.15 times as many as those under the sewage water irrigation mode separately.In severe saline soil,the activities of urease,phosphatase,and dehydrogenase under the feculence-clearing rotation irrigation mode were 0.98,1.12,1.31 times as many as those under the sewage water irrigation mode separately.The feculence-clearing rotation irrigation is critical in improving the three enzyme activities and soil fertility of the degraded saline wetlands.This study proved that irrigation with paper mill effluent not only could improve soil fertility,but also could significantly increase enzyme activity of the degraded saline-alkaline lands.The increase of soil enzyme activity showed that： the quality of the salinization soil has been effectively improved by irrigation with treated paper mill effluent.