Abstract: Biosolids are rich in nutrient and biostimulants and will impact plant growth, and stress tolerance. Effects of biologically active substances of bio-solids on turfgrass quality and root growth of Kentucky bluegrass (Poa pratensis L.) associated with drought tolerance were examined. Split-plot design was used in this study with the main plots of soil moisture and the subplots of biosolids. Main plot treatments included well-watered and drought stress. Subplots treatments were all applied nitrogen 75 mg·kg^-1 and included biosolids 1x rate (75 mg·kg^-1 nitrogen completely provided by biosolids); biosolids 0.5x rate (37.5 mg·kg^-1 nitrogen provided by biosolids, and 37.5 mg·kg^-1 nitrogen provided by NH₄NO₃ solution); control (75 mg·kg^-1 nitrogen completely provided by NH₄NO₃ solution). Bisolids 1x rate and biosolids 0.5x rate significantly improved turfgrass quality, leaf relative water content and root growth index of Kentucky bluegrass than control under both water regimes (P<0.05) indicating that biologically active substances of biosolids improved the growth and drought tolerance of Kentucky bluegrass. The turfgrass quality of biosolids 0.5x rate was significantly higher than biosolids 1x rate and control during drought stress (P<0.05), whereas biosolids 1x rate improved root length and root volume of Kentucky bluegrass by 17% and 11.7% (P<0.05), respectively, compared with biosolids 0.5x rate under drought stress. These results indicated that biosolids 0.5x rate had a good effect on turfgrass quality, and biosolids 1x rate promoted the root growth of Kentucky bluegrass under drought stress.

Key words: Biosolids, Drought, Poa pratensis L., Root

摘要： 污泥富含营养元素和生物活性物质,对植物的生长及耐旱性有一定的影响。为明确污泥中生物活性物质对草地早熟禾(Poa pratensis L.)坪观质量和根系生长指标的影响,采取裂区试验设计:主处理为水分处理,包括干旱胁迫和充分浇水2个水平;副处理为污泥处理,每个处理均施氮75 mg·kg^-1,包括:全污泥处理(利用污泥提供的氮含量为75 mg·kg^-1);半污泥处理(利用污泥提供的氮含量为37.5 mg·kg^-1,利用硝酸铵溶液提供的氮含量为37.5 mg·kg^-1);对照(利用硝酸铵溶液提供的氮含量为75 mg·kg^-1)。结果表明:与对照相比,在2种水分条件下,全污泥和半污泥处理均能显著提高草地早熟禾的坪观质量、叶片相对含水量以及各项根系生长指标(P<0.05),表明污泥中的生物活性物质能够促进草地早熟禾的生长并提高其耐旱性。在干旱处理后期,半污泥处理的草坪坪观质量显著高于全污泥处理和对照(P<0.05);而全污泥处理的根系总长度和根系总体积分别比半污泥处理的高17%和11.7%(P<0.05),表明半污泥处理有利于提高草坪坪观质量;而全污泥处理对草地早熟禾根系生长的促进作用更大。

关键词: 污泥, 干旱, 草地早熟禾, 根系