工业和住宅污泥对大叶相思种子萌发以及幼苗生长参数的影响

在孟加拉国吉大港大学林业与环境科学院苗圃内,评价了污泥对大叶相思种子萌发以及幼苗生长的作用。播种前,将污泥与营养匮乏的自然林土壤按不同比率混合,分别在播种后的第1,2和3个月时,记录种子萌发情况和幼苗生长参数（枝条和根系的长度、直径、枝条的鲜重和干重、根和总的干物质量）。在播种前和幼苗采收后,分别测定各个处理的污泥-土壤混合物的理化参数（pH值、有机碳、氮、磷、钾）,以及重金属含量（铬、镍、锰、镉、锌）。结果表明,与对照相比,污泥-森林土壤混合物中播种的种子萌发率和幼苗生长参数发生显著变化。土壤-污泥按2：1混合时,种子萌发率最高（90%）,幼苗生长速率和生物量最大,有机碳和氮磷钾含量也最高。混有工业污泥的土壤中重金属含量要高于混有住宅污泥的土壤。在工业污泥土壤中,污泥-土壤按1：1混合时,重金属含量最高。据此推荐,在退化森林土壤中,土壤-污泥以2：1混合较适合大叶相思种子萌发和幼苗生长。

Effects of industrial and residential sludge on seed germination and growth parameters of Acacia auriculiformis seedlings

A study was conducted to evaluate the effects of sludge (industrial and residential) on seed germination and growth performance of Acacia auriculiformis seedlings at the nursery of Institute of Forestry and Environmental Sciences, Chittagong University (IFESCU), Bangladesh. Before sowing of the seeds, different combinations of sludge were incorporated with the nutrient-deficient natural forest soils. Seed germination and growth parameters of the seedlings (shoot and root length, collar diameter, fresh and dry weight of shoot, and root and total dry biomass) were recorded after one, two and three months of seed sowing. Physio-chemical parameters (pH, organic carbon, nitrogen, phosphorus, and potassium) and heavy metals (chromium, nickel, manganese, cadmium and zinc) of each treatment were also analyzed before sowing of seeds and after harvesting of seedlings. Results show that the seed germination percentage and the seedling growth parameters varied significantly in the soil added with sludge in comparison to control. The highest germination percentage (90%) was observed in the treatment of soil with residential sludge of 2:1 compared to control. The highest growth and biomass of the seedlings as well as the maximum percentage of organic carbon and nutrients (N, P and K) were also recorded in the same combination. Soil added with industrial sludge had a higher concentration of heavy metal than that of residential sludge. The highest concentrations of heavy metals were found in soil added with industrial sludge of 1:1. It is recommended that soil added with residential sludge of 2:1 provide good condition for better seed germination and growth of A. auriculiformis seedlings in degraded forest soil.