The invention provides a method for improving tolerance of soybeans to
petroleum and lead contaminated soil by applying
photosynthetic bacteria, and relates to a method for improving soil tolerance. The method comprises the following steps of: before soybean seeds are sowed, spraying dilute
bacterial agent to soil, diluting
bacterial agent, soaking the seeds in the dilute
bacterial agent and
sowing the seeds; after the seeds are sowed, infiltrating dilute
bacteria; and in the soybean growth process, monitoring the content of soybean
chlorophyll every week from the
seedling stage: selecting typical plants in a
population, selecting fully-unfolded leaves at the topmost node positions, determining the content of the
chlorophyll, or from the podding starting stage to the seed filling stage, respectively taking and spraying
calcium chloride solution on leaf surfaces once, and then taking, diluting and spraying
photosynthetic bacteria agent
stock solution once. The method for improving the tolerance of the soybeans to the
petroleum and lead contaminated soil by applying the
photosynthetic bacteria has the advantages that the use cost is low, the process is safe, the environmental friendliness after use is good, the contents of the
chlorophyll and
carotenoid are increased very obviously, the plants are high, the stalks are thick, the
dry weight and the
fresh weight are greatly improved, the resistance indexes such as contents of
proline, POD (
peroxidase) and
phytochelatin are improved, the content of malonaldehyde is reduced, the soybeans can tolerate the
petroleum and lead contaminated soil, the physical and chemical properties of the soil can be remarkably improved and the
soil fertility is improved.