疏浚底泥改良土壤理化性质促进芦苇快速定植研究

采用盆栽实验考察了湖泊疏浚底泥和河道疏浚底泥不同利用方式下对土壤基底性质的改良进而促进水生植物芦苇快速定植扩繁效果.试验结果表明,湖泊底泥在竹炭改良利用方式下(L-A实验组)可提高芦苇单位面积分蘖数增长率,最高可达(3.06±0.36) m~(-2)·d~(-1),在与绿化土壤混合利用方式下(L-M实验组)可提高芦苇株高,最高达(155.5±0.7) cm;而河道底泥在与绿化土壤混合利用方式下(R-M实验组)芦苇的单位面积分蘖数增长率和株高效果最优,分别可达(4.76±0.18) m~(-2)·d~(-1)和(139.5±3.5) cm.分析原因发现,施加底泥可以明显降低土壤容重,并提高有机质和磷含量,从而促进芦苇分蘖数增长率的提高.基底微生物群落多样性和群落中Micrococcaceae(微球菌)的丰度也显著提高,进一步证实了施加底泥可以改良基底理化性质从而促进芦苇快速定植.

Improvement of soil physico-chemical properties by dredged sediments to promote the rapid colonization of Phragmites

To promote the rapid colonization of aquatic plant Phragmites, the plot experiments were conducted to investigate the enhancement of the soil basal properties with the different utilization mode of lake and river sediment. The experimental results showed that the lake sediment can improve the tillers growth rate of Phragmites to (3.06±0.36) m^-2·d^-1 under the utilization mode of charcoal(L-A experimental group). With the utilization of soil mixed mode(L-M experimental group), the height of Phragmites increased to (155.5±0.7) cm. Regarding to river sediment, tillers growth rate and height of Phragmites showed greatest enhancement under the mixed mode of soil and river sediment (R-M experimental group), which reached up to (4.76±0.18) m^-2·d^-1 and (139.5±3.5) cm respectively. The application of sediment can significantly reduce the soil bulk density and increase organic matter and phosphorus content of plants, which is conducive to the improvement of Phragmites tillers growth rate. The diversity of basal microbial community and the abundance of Micrococcaceae in the community were also significantly improved, indicating that the application of sediment can improve the physico-chemical properties of the substrate and promote the rapid colonization of Phragmites.