Effect Of Different Treatments Of Bacteria On Copper And Chromium Contaminated Soil And Maize

The test soil was copper-chromium-contaminated soil collected from a sewage irrigation area in Qi Xian,Jinzhong City,Shanxi Province.Pot experiments were conducted to study the basic chemical properties,enzyme activities,copper and chromium forms,and growth of corn in different growth stages of maize after drying,decomposition,and application of biochar to the soil of the sewage irrigation area.Physiological characteristics,the impact of heavy metal content.The results showed that:(1)Different treatment bryophytes had little effect on the soil pH value.The application of ganoderma fungal bacillus directly and after maturity in the seedling stage and heading stage reduced the pH value of the soil.The rest of the treatments had no significant difference compared with the blank.The content of soil organic matter was increased after the treatment of different strains of bacillus,and the direct application of Ganoderma lucidum had the highest increase,and the content of organic matter increased by 57.42%-61.17%.Different treatment of bacillary dysentery increased the total salt content of soil.With the increase of growth period,the total salt content also increased,but the difference was not significant compared with the blank.(2)Different treatments of bacillary dysentery have a certain degree of improvement effect on the available N,P,K content of the soil,which is the highest in the heading stage.At the seedling stage,the direct application of quick-acting N to Ganoderma lucidum increased by 38.01%,and the increase of available P for each treatment ranged from 12.99%to 48.17%.The effect of three different treatment of Ganoderma lucidum on the availability of rapid-acting K was improved.More obvious,up to 490.22mg/kg.In the heading stage,the application of quick-acting N was increased by 1.1-fold when the Ganoderma lucidum was decomposed,and the direct application of quick-acting P to Pleurotus ostreatus was increased by 30.34%,and the direct application of quick-acting K to Ganoderma lucidum was increased by 85.17%.In the mature period,the direct application of quick-acting N to the Hericium erinaceus increased by 35.89%,and the quick-acting P increased by 18.14%and the quick-acting K increased by 96.48%.From heading to maturity,the available nitrogen,phosphorus and potassium contents in the soil began to show a downward trend.(3)By analyzing the effects of different treatments on the four enzymes in soil at different stages,it can be roughly seen that the direct application of bacillary dysentery can better promote the four enzymes of the soil than the decomposition and the production of biochar.Enzymatic activity.In the seedling stage,direct application of different strains of bacillus was more than 2 times higher than sucrose enzyme activity.At the heading stage,the direct invertase activity of Hericium erinaceus increased by 39.08%.In the mature period,the direct application of sucrase activity by Hericium erinaceus increased by 55.56%.In each period,the activity of catalase,phosphatase and urease in the soil increased little,and with the change of corn growth period,the activity of each enzyme showed a downward trend.(4)In different periods,the forms of copper and chromium in the soils under different treatments were basically present in the iron-manganese oxidation state,organic binding state and residue state.At the ripening stage,copper and chromium in the soil are largely distributed in the form of residual and organic bound states.It indicated that the application of bacillus caused the heavy metal copper and chromium to be fixed to the residue state and organic binding state,which reduced the absorption of corn.(5)In different periods,different treatment of bacillary dysentery promoted the growth of corn and promoted the increase of chlorophyll,malondialdehyde and catalase in maize.In the mature period of corn,Hericium erinaceus biochar has increased the chlorophyll 1.82 times,and malondialdehyde and catalase also have a small increase.Chlorophyll and malondialdehyde increased from heading to maturity,and catalase decreased.(6)In different periods,heavy metals such as copper and chromium were found in the roots of plants.After application of different strains of bacteria,copper and chromium in the roots and fruits were reduced compared to the blanks.There was no significant regularity in heavy metals in the other parts.