黄河三角洲废弃盐田复垦土壤质量动态演变分析

Reclaimed Soil Quality Dynamic Evolution of Abandoned Salt Field in the Yellow River Delta

以山东省寿光市清水泊农场农田及7个不同复垦年限废弃盐田土壤为研究对象,采用空间代替时间序列方法对不同土层(0~20、20~40、40~60、60~80、80~100cm)土壤理化性状与微生物特性进行了研究.结果表明:(1)复垦后土壤含盐量降低,土壤有机质、全氮、速效磷及速效钾含量增加,各养分含量在复垦8a时达到最大值,基本达到农田水平;(2)土壤中细菌、放线菌数量随着复垦年限的增加呈先增加后下降的趋势,而真菌数量则持续上升;(3)复垦有利于土壤脲酶、碱性磷酸酶、蔗糖酶和过氧化氢酶的提高,复垦年限越长,酶活性提高越显著;(4)通过构建复垦质量变化预测定量模型,预测复垦土壤有机质、全氮、速效磷及速效钾含量达到对照农田水平分别需8.75、8.45、8.24、8.41a;(5)经主成分分析得出,影响复垦土壤质量演变的主要因子为蔗糖酶、过氧化氢酶、有机质和细菌.本文分析了废弃盐田复垦土壤各理化和微生物指标的变异特征及时空分布规律,可为科学指导黄河三角洲废弃盐田复垦区土壤综合治理和农业可持续发展提供理论依据.

Methods of temporal series replaced with spatial series were used to study the changes of soil physico-chemical properties and microbial in farmland and abandoned salt field with different reclamation histories,located in Shouguang of Shandong Province.Our results indicated that:(1)Reclamation declined soil salt content and increased soil organic matter(SOM),total nitrogen(TN),available phosphorus(AP),available potassium(AK)nutrient contents reached the maximum value and basically reached the level of farmland in 8 reclamation years.(2)The amounts of bacteria and actinomycetes were first increased and then declined with the increasing of reclamation history,the quantity of fungi increased continuously.(3)Reclamation was beneficial to the enhancememt of soil urease(URE),alkaline phosphatase(ALP),invertase(INV)and catalase(CAT).The longer the reclamation period,the more significant the enzyme activity.(4)A quantitative model was established to assess the change of reclamation quality and predict the required years for the nutrient of abandoned salt field to the levels of farmland.It takes 8.75,8.45,8.24 and 8.41 a for SOM,TN,AP,AK to reach the farmland level,respectively.(5)Principal component analysis showed that INV,CAT,SOM and bacteria were the predominant factors affecting the quality evolution of reclaimed soil.Overall,This paper analyzed the spatial and temporal distribution of soil physical,chemical and microbial indexes,and provided a theoretical basis for soil comprehensive management in the abandoned salt fields and the future agricultural sustainable development in the Yellow River Delta.