The Remediation Of Photosynthetic Bacteria On Peanut Continuous Cropping Soil

Arachis is a kind of sensitive crop of continuous cropping. Continuous cropping caused deterioration of soil biological environment and physical and chemical characteristics, resulting in poor growth and yield of peanut. Photosynthetic bacteria have the function of photosynthetic carbon fixation, nitrogen fixation, decomposition of poison, and so on. In order to study the effect of photosynthetic bacteria on the soil of continuous cropping of peanut, in this paper, We used the mixed bacteria (1:1) of 2 strains of photosynthetic bacteria liquid which preserved in our research group. Different dilutions dealt with continuous cropping peanut soil of 10 years, inoculating and cultivating indoor, monitoring the change of soil microbial flora, enzyme activity and soil physical and chemical characteristics regularly, and testing the effect via plant pot, Our purpose is to alleviate peanut continuous cropping obstacle using biological methods, providing theoretical guidance for developing a new soil conditioner. The results obtained as follows:1. The main microbial flora of peanut continuous cropping soil indoor treatment: Original liquid (original concentration of bacteria) and 30 times diluted bacteria liquid(30 times diluted mixture liquid of bacteria) increased the number of culturable bacteria and actinomycetes and diversity of bacterial community structure in most sampling time points, reducing the number of fungi and its diversity of community structure.30 times liquid and original liquid change soil type from fungi to bacteria, improving soil microbial flora obviously, most effects are better than commercial continuous cropping agent after 30 d. The effects of original liquid and 30 times liquid are better than commercial continuous cropping agent in most sampling time points.2. The enzyme activity of peanut continuous cropping soil indoor treatment:Original liquid and 30 times liquid increased the most of enzymes that urease, invertase, acid phosphatase alkaline phosphatase and catalase activity significantly in most sampling time points, most effects were better than commercial continuous cropping agent from 30 d, the duration of effects was longer than commercial continuous cropping agent obviously.3. The pH value of peanut continuous cropping soil indoor treatment:Soil pH value was measured at 90 d, all treatments increased pH value of peanut continuous cropping soil, soil pH value increased from 5.97 to neutral or alkaline, reducing the acidification caused by continuous cropping. The effects of 50 times liquid,30 times liquid and original liquid are better than commercial continuous cropping agent.4. The nutrient content of peanut continuous cropping soil indoor treatment:Soil nutrient content was measured at 90 d, original liquid and 30 times liquid increased the content of organic C, total N, alkaline hydrolysis N, available P, available K obviously, the effects were better than commercial continuous cropping agent.5. The correlations of each index of peanut continuous cropping soil indoor treatment: Soil pH value and most of soil nutrients content have a more significant positive correlation with bacteria and actinomycetes quantity and most of enzyme activity, and have a more significant negative correlation with fungi quantity; Five kinds of soil enzymes activity have a significant positive correlation with bacteria and actinomycetes quantity, and have a more significant negative correlation with fungi quantity.6. The results of pot experiment:(1) Original liquid and 30 times liquid increased plant height, root length, root width, shoot dry weight, root dry weight, nodule number, net photosynthetic rate, stomatal conductance and relative content of chlorophyll of peanut obviously, the effects of 30 times liquid were better than commercial continuous cropping agent in all indexes, the effects of original liquid were better than commercial continuous cropping agent in root length, nodule number, stomatal conductance and relative content of chlorophyll. The effects of original liquid and 30 times liquid in main microbial flora, enzyme activity, pH value and nutrient content of pot soil are better than commercial continuous cropping agent. (2) The correlations between physiology indexes of plants and other indicators:All physiology indexes of plants have a more significant positive correlation with bacteria and actinomycetes quantity and soil pH value, and have a more significant positive correlation with most of the enzyme activity and nutrients content, have a more significant negative correlation with fungi quantity.In summary, photosynthetic bacteria has significant conditioning effects on peanut continuous cropping soil,30 times liquid is optimal concentration, the effects are better than commercial continuous cropping agent obviously.