绿化植物废弃物覆盖对上海城市林地土壤肥力的影响

研究绿化植物废弃物覆盖对上海城市林地土壤肥力的影响。结果表明:绿化植物废弃物覆盖能降低土壤密度,提高土壤保水能力,增加总孔隙度和毛管孔隙度尤其是非毛管孔隙度;在试验设计的6120kg·hm-2覆盖量范围内,覆盖能显著增加土壤有机质、全氮、全磷、水解性氮、有效磷和速效钾含量,且覆盖用量与这些土壤肥力指标成极显著正相关;土壤全钾含量的增加要在覆盖160天后且覆盖量高时才出现;覆盖后土壤微生物生物量碳、氮含量也显著增加,微生物周转速率加快,周期缩短,转移量增加,土壤微生物活性增强,有利于土壤养分的循环和保持;土壤微生物生物量碳、氮含量与土壤主要肥力指标显著正相关,能有效评价绿化植物废弃物覆盖对土地的改良效果。绿化植物废弃物覆盖对提高城市土壤质量、降低绿地养护费用有积极作用,也有利于节约型城市园林绿化的建设。

Effect of Mulching Greenery Waste on Soil Fertility of Municipal Forest Land from Shanghai

Effect of mulching greenery waste on soil fertility of municipal forest land was studied. Result showed that greenery waste mulching reduced soil bulk density, improved water retention capacity of soil, and increased soil total porosity,capillary porosity,and especially non-capillary porosity.In the range of mulching amounts(6120kg·hm~(-2)) applied in this experiment, mulching also significantly enhanced contents of organic matter, total nitrogen, total phosphorus, hydrolyzable nitrogen, available phosphorus and available potassium in soil, and the amount of mulch had a remarkable positive correlation with these soil critical nutrition indexes. However, the increase of total potassium was not observed until 160 days after the treatment with high amount of mulch. The mulch also significantly raised the contents of microbial biomass carbon and microbial biomass nitrogen, accelerate microbial turnover rate, shorten microbial turnover time, increase microbial transfer capacity and activate soil microbial activity, which was beneficial to recycling and maintaining soil fertility. Microbial biomass carbon and microbial biomass nitrogen had a significant positive correlation with the soil critical nutrition indexes, which could be used to evaluate the remediation efficiency of mulching greenery wastes on land. The mulching of greenery wastes had a positive role in improving soil quality and reducing maintenance costs for green space which was favor to constructing the economical landscape and gardening for the urban.