污水灌溉对大豆幼苗生长和根际微生物的影响

采用沙颍河污水,分别以全清水(CK)、全污水和清污比1∶1、2∶1、3∶1的污水灌溉盆栽大豆,研究不同稀释倍数的污水灌溉对大豆幼苗生长和根际微生物的影响。结果表明,灌溉沙颍河污水对大豆幼苗生长和根际微生物的影响明显。污水含量高时,会显著抑制大豆幼苗、根际细菌和放线菌的生长,刺激真菌的生长。随污水含量的不断减少,大豆幼苗生长指标、叶绿素含量呈现先增高后降低的变化规律,用清污比2∶1的污水灌溉时,大豆幼苗生长指标和叶绿素含量(2.35 mg/g)达到最高,地上部分干质量、叶绿素b增加最多,与全清(CK)相比,分别增加了127.76%、119.27%;相对电导率随污水含量的减少而降低;根际微生物中细菌、放线菌的数量随污水含量的降低呈现先增加后减少的变化趋势,用清污比1∶1的污水灌溉时,其数量达到最大,分别为3.10×107cfu/g、3.33×106cfu/g。当污水含量比例适当时,污水中的营养成分对大豆幼苗和微生物的生长有刺激作用,其中多项指标以(1∶1)~(2∶1)稀释度的污水增效作用最为明显。

Effect of Sewage Irrigation on Growth of Soybean Seedling and Its Rhizosphere Microorganisms

The sewage from Shaying River was used to irrigate the potted soybean with ratio of clear water to sewage at 1∶1,2∶1 and 3∶1.The growth of soybean seedling and its rhizosphere microorganisms were studied.The results showed that the influence of sewage concentration irrigation on growth seedling of soybean and its rhizosphere microorganisms was obvious.High sewage concentration could inhibit the growth of soybean seedling and bacteria,actionomycetes while stimulate fungi.Along with the sewage concentration decreasing continuously,the growth index and contents of chlorophyll of soybean presented the law of first increasing and then decreasing while relative electric conductivity decreased.The growth index and contents of chlorophyll of soybean was the highest with ratio of water to sewage at 2∶1.Shoot fresh weight and Chlb reached to maximum,and increased by 127.76%,119.27% compared with CK,respectively.The quantities of bacteria,actionomycetes presented the law of first increasing and then decreasing.The quantities of bacteria and actionomycetes were the highest,3.10×107 cfu/g soil,3.33×106 cfu/g soil respectively with ratio of water to sewage at 1∶1.When the sewage concentration was proper,the nutrient components of sewage had stimulative effect to the growth of soybean and its rhizosphere microorganisms.The promotion effect of sewage was obvious at a ratio of water to Shaying River sewage of(1∶1)-(2∶1).