污泥和吲哚丁酸对草地早熟禾的生长和耐旱性的影响研究

摘要

Biosolids contains a wealth of nutrients and biologically active substances (BAS) and is useful for soil improvement and as fertilizer following appropriate treatment.The purpose of this research was to study the effects of sewage sludge obtained from Jiuxianqiao sewage treatment plant in Beijing and exogenous auxin on the growth and drought tolerance of kentucky bluegrass (Poa pratensis).A split plot trial design was used with main plot treatments being moisture availability (well-watered and drought stress).Subplots included treatments of sewage sludge,2 μmol · L-1 endogenous indole butyric acid (IBA) and a control.Three months after establishment watering in the drought stress plots was stopped until the soil water content fell to 25％ of field capacity.Subsequently irrigation commenced again for a month,with held again until 25％ field capacity and then fully irrigated for another month.The well-watered treatments were fully irrigated for the duration of the study.Turf quality,wilt rating,leaf relative water content,chlorophyll and carotenoids content,proline content,ABA content,IAA content and MDA (malondiadehyde) content of all treatments were measured at every beginning and end of drought stress.Sewage sludge and endogenous IBA improved turf quality and leaf chlorophyll content under well-watered conditions,and increased leaf IAA content (P＜0.05);sewage sludge had a more lasting effect than IBA.Both sewage sludge and IBA enhanced the turf quality,leaf relative water content and chlorophyll content (P＜0.05) under the drought stress.At the end of drought stress,the proline contents of control,sewage sludge and IBA treatments were respectively 433,385 and 254μg · g-1,ABA content was1.74,0.68 and 0.70 μg · g-1,respectively and MDA content 62.39,40.08 and 25.38nmol· g-1,respectively.Proline,ABA and MDA contents of sewage sludge and IBA treatments were significantly lower than that of the control (P＜0.05).The study indicated that both sewage sludge and IBA could promote the growth of Kentucky Bluegrass;sewage sludge raised drought resistance while IBA enhanced drought tolerance.%污泥中含有丰富的矿质营养和生物活性物质,经无害化处理后可以作为良好的土壤改良剂和植物肥料.试验旨在研究并对比污泥和外源吲哚丁酸(IBA)对草地早熟禾生长及耐旱性的影响.污泥取自北京市酒仙桥污水处理厂.试验采用裂区设计,主处理包括:充分浇水和干旱处理,副处理包括污泥处理、外源IBA(2μmol·L-1)处理和对照.草地早熟禾播种生长3个月后干旱处理组不再浇水,至土壤水分含量降到25％田间持水量时复水,一个月后再次不浇水干至25％田间持水量,再复水一个月.在每次干旱开始和结束时,测定草地早熟禾坪观质量、叶片相对含水量、叶绿素和类胡萝卜素含量、脯氨酸、脱落酸、吲哚乙酸及丙二醛含量.结果表明:在充分浇水条件下,污泥和IBA能改善草地早熟禾的坪观质量,提高叶片叶绿素含量和IAA含量(P＜0.05),且污泥的作用比IBA更持久;干旱胁迫下,污泥和外源IBA处理均能显著提高草地早熟禾的坪观质量,降低萎蔫度,提高叶片相对含水量和叶绿素含量(P＜0.05).2次干旱处理结束后,对照、污泥和IBA处理的脯氨酸含量分别为433,385和254 μg·g-1,脱落酸含量分别为1.74,0.68和0.70 μg·g-1,丙二醛含量分别为62.39,40.08和25.38 nmol·g-1,污泥和IBA处理的草地早熟禾叶片中脯氨酸、脱落酸和丙二醛含量均显著低于对照(P＜0.05).试验结果说明污泥和外源IBA能促进草地早熟禾的生长,污泥能提高草地早熟禾的抗旱性,IBA能提高其对干旱胁迫的耐受性.