园林废弃物堆肥用于屋顶绿化轻型基质的配方筛选

Screening of light substrate formulations of garden waste compost for roof greening

针对用于屋顶绿化基质的泥炭存在资源不足的问题,以园林废弃物堆肥、泥炭和珍珠岩配制9组混合基质,以马蔺为供试植物,通过基质筛选和屋顶绿化模拟栽培实验研究园林废弃物堆肥替代泥炭用于屋顶绿化轻型基质的效果。结果表明,9组基质干容重为0.08~0.11 g·cm^(-3)、饱和水容重为0.46~0.56 g·cm^(-3)。添加20%泥炭的处理组总孔隙度和通气孔隙度较小,持水孔隙度较大。9组基质的pH和EC适宜植物生长。结合隶属度评价结果和北京市《屋顶绿化规范》,筛选T3组(10%园林废弃物堆肥+90%珍珠岩)和T6组(10%园林废弃物堆肥+10%泥炭+80%珍珠岩)2组处理用于屋顶绿化模拟栽培实验。结果表明,2组基质全氮、有效磷、速效钾质量分数变化趋势基本一致,T6组中10%园林废弃物堆肥和10%泥炭的混合加入提升了基质全氮和有机质质量分数,但抑制了基质有效磷和速效钾的释放。2组处理中的马蔺均生长良好,T3组(1.475 mg·g^(-1))马蔺叶绿素质量分数比T6组(1.154 mg·g^(-1))处理提升了27.82%,而T6组基质促进了株高增长、地上部和地下部生物量积累。主成分综合评价得分为T3组>T6组,即10%园林废弃物堆肥与90%珍珠岩混合配制的基质得分最高,能够替代泥炭用于屋顶绿化中。本研究结果可为园林废弃物堆肥用作屋顶绿化轻型基质提供参考。

In order to solve the problem of insufficient resources of peat in light substrate of roof greening,nine groups of mixed substrates were prepared by using garden waste compost,peat and perlite,and Iris lactea Pall was selected as test plant.The effect of garden waste compost replacing peat used in the light substrate of roof greening were by carrying out the substrate screening and roof greening simulation cultivation experiment.The results showed that the dry bulk density of nine treatments was 0.08~0.11 g·cm^(-3),and saturated water bulk density was 0.46~0.56 g·cm^(-3).The treatment with 20%peat had smaller total porosity,aeration porosity,and larger water holding porosity.The pH and EC of nine treatments were all suitable for plant growth.Combined with the comprehensive evaluation results of membership function and the code for roof greening in Beijing,T3(10%garden waste compost+90%perlite)and T6(10%garden waste compost+10%peat+80%perlite)were screened for the simulated cultivation experiment of roof greening.The results showed that the dynamic change trends of total nitrogen,available phosphorus and available potassium in the two treatments were basically the same.The mixed addition of 10%garden waste compost and 10%peat of T6 elevated the total nitrogen and organic matter content in the substrate,but restricted the release of available phosphorus and available potassium.The leaf chlorophyll content of Iris lactea Pall in T3(1.475 mg·g^(-1))was 27.82%higher than that in T6(1.154 mg·g^(-1)),but the growth of plant height,the biomass of both aboveground and underground in T6 were promoted.The comprehensive score evaluation showed that T3 gained higher score than T6,that is,the substrate constituted by 10%garden waste compost and 90%perlite had the highest score,which could replace peat for roof greening substrate.This study can provide a scientific reference for the application of garden waste compost as light substrate for roof greening.