不同作物根际微生物差异的研究

Quantity Difference of Rhizosphere Microbe of Different Crops

采用两米以下生土做试验(避免熟土影响试验),明显看出不同栽培作物根际微生物三大种群存在着较大的差异。一般根际三大微生物种群数量皆高的作物很少,多为某一种微生物数量较多。苗期微生物数量较少,随着生育进程根量的增加,气温的提高,微生物数量明显增加。施肥可以明显促进土壤微生物的繁衍,但不同作物不同菌类对施肥反应存在差异,其中真菌对施肥反应远不及细菌和放线菌反应敏感。不同作物以花生、小茴香根际放线菌对施肥反应不敏感,而甜菜施肥处理对细菌、真菌增加不多,但对放线菌数量影响很大。值得指出的是不同作物根际微生物对不同施肥种类的反应,与作物生长对不同施肥的反应几乎完全一致,即表现为NPK、NP综合施肥对微生物数量增加最为有效。相比之下,单施N、P、K远不及综合施肥的效果。这种现象可看作是肥料促进根土系统、根土系统促进微生物繁衍的过程。

The study indicates that after cultivating different crops on unused soil below two metres,numbers of three main species of rhizosphere microbe are much more different.In general,there are few crops of which all numbers of three main species of rhizosphere microbe are high. And among most of crops with rhizosphere microbe,some species are more than another two ones.The study also indicates that numbers of rhizosphere microbe are less at seedling stage,and along with crop growing,root numbers increasing and air temperature advancing,numbers of rhizosphere microbe increase obviously.Fertilization can accelerate obviously rhizosphere microbe to multiply,but reaction of different crop and different microbe form to fertilization is different.Among them,fungi reaction is not less sensitive to fertilization than bacteria and antinomyces.Among different crops,reactions of rhizosphere antinomyces of peanut and cumin are sensitive while rhizosphere bacteria and fungi of beet are less.Be worth of mentioning,reactions of different crops to fertilization form almost coincide with ones of crops growing to one,that is to say,after fertilizing NPK and NP,rhizosphere microbe numbers increase most.Compare to NPK and NP,effect of fertilizing alone N、P、K is not farther inferior to integrated fertilization.This can be regared as a process in which fertilization promotes root-soil system at the same time root-soil system also advances microbe to multiply.