Effects Of Different Microbial Agents On Physicochemical Property And Enzyme Activities In Panax Ginseng Continuous Cropping Ground

Panax Ginseng C.A.Mey is a valuable Chinese herbal medicine, the main production in Jilin province region. Panax ginseng cannot be cultivated on the same plot of land consecutively within decade years or ginseng root would turn rusty and rot. This is called ginseng discontinuous cultivating. This has become the limiting factor for the development of ginseng industry. Improve the soil quality to provide the ginseng continuous growth has become the concern of the researchers.The experiment use the biological control means, through the method of applied microbial agents in Panax ginseng continuous cropping ground to improve the quality of old ginseng land soil, enhances soil fertility, provide certain theoretical basis and basic data for solving the problem of continuous cropping obstacle of ginseng at the same time. Four kinds of different microbial agents was used in the test: prebiotics cropping agent(A), Trichoderma harzianum(B), agent “5406”(C) and Paenibacillus polymyxa agent(D), each agent is provided with 3 concentration gradient. Determination of the index bulk density, pH, electrical conductivity, content of organic matter, available NPK, sucrase, catalase, urease and phosphatase after applying agent in the continuous cropping ground, with ginseng production in each agent treatment, comparison and analysis of the results to select the optimal agent and its concentration for improvement the old ginseng soil fertility level. The experimental results show that: Physical properties:Each agent has a certain impact on the bulk density and total porosity of soil parameter, but the overall effectis not obvious. Chemical properties:Four kinds of microbial agents can effectively improve soil pH value, reduce soil acidification status, but each agent with the concentration change has different growth trend. Agent A and agent C with the concentration increased, pH value was "∧" type change trend, both of them are the middle concentration effect is the best, agent B and D changes in the opposite trend, with the increase of the concentration, the value of pH in "V" type change trend, agent B is the low concentration treatment and agent D is high concentration effect is good, compared to the 4 kinds of agents, the best treatment effect of soil pH value to enhance the biggest is D3. The effect on the conductivity of agent A, C, D is along with the concentration increased, the conductivity is a "V" type change trend, the A agent of high concentration A3 is the strongest conductivity, while the other two are the best effect of low concentrations, agent B with concentration increased, conductivity showed tendency of " ∧" type, the best treatment effect is the concentration of B2. Each agent can significantly increase the content of organic matter in soil, but the overall effect of agent A and agent B is better, the concentration changes is A2>A1>A3 and B2>B1>B3. Effect of 3 different concentrations in nutrient were significant, sterilizing agent C, the other 3 kinds of agent can increase the content of alkali hydrolyzable N, which is the best treatment group B2 and A3, The four kinds of microbial agents were reduced the concentration of available phosphorus in soil, but with the increase of the concentration, content of available phosphorus is gradually increased in microbial inoculum B and C, the content of C3 was most close to CK, because the microorganism is phosphate solubilizing bacteria. The content of each concentration of each agent can significantly increased available potassium, which is the best groups is A3 and C1. Enzyme activity:Four microbial agents could significantly increase the soil invertase activity, but in addition agent C, the other 3 kinds of agent showed high concentration of inhibition is concentration, better effect is the concentration of middle, agent C is with the increase of concentration, the enzyme activity was increased gradually, the best effect on the invertase activity is treatment of low concentration in B. Each agent can enhance the activity of catalase, but agent A in the concentration of A2 、 low concentration of B1 in B have the best effect. Four kinds of bacteria can enhance the activity of urease, and the effect is similar with catalase activity, the best is B1 and A2.Effects of four kinds of bacteria on the phosphatase activity is significant, can significantly increase the content, the best treatment effect is C3 and B1, agent C is with the increase of concentration, the effect gradually strengthened, and the change of agent B was opposite, with the increase of concentration, the enzyme activity is inhibited.The synthesis of 4 agents on the above indicators and ginseng yield effect, 400 g/m2 Prebiotics cropping agent(A) and 5 g/m2 Trichoderma harzianum(B) application rate on old ginseng soil improvement effect is best.