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ObjectiveTo investigate the effects of the inoculation of potassium-solubilizing bacteria on the rhizosphere soil microenvironment of Paris polyphylla var. yunnanensis. MethodThe effects of different potassium-solubilizing bacteria on the physical and chemical properties， microbial community structure， and soil enzyme activity in the rhizosphere soil of P. polyphylla var. yunnanensis were investigated by pot planting at room temperature. The correlation of various indexes was analyzed. ResultThe inoculation with different potassium-solubilizing bacteria could significantly affect the physical and chemical properties of rhizosphere soil of P. polyphylla var. yunnanensis. The mass fractions of available nitrogen， available phosphorus， and available potassium were 24.5-90.5 mg·kg-1， 2.53-25.9 mg·kg-1， and 132-312 mg·kg-1， respectively， and the soil pH was 7.08-7.75， which were in line with the optimal ranges of P. polyphylla var. yunnanensis planting. The inoculation of different potassium-solubilizing bacteria could affect the number of bacteria， actinomycetes， and fungi in rhizosphere soil to varying degrees. The transformation of soil from "fungal type" to "bacterial type" marks the improvement of soil fertility. It also affected the enzyme activity of rhizosphere soil， and the activities of neutral phosphatase， protease， and polyphenol oxidase showed an increasing trend. The correlation analysis showed that the number of bacteria was negatively correlated with the number of fungi （r=-0.856， P<0.01）， positively correlated with the number of actinomycetes， the content of available nitrogen and available potassium， and negatively correlated with soil pH. ConclusionThe inoculation of potassium-solubilizing bacteria can effectively improve the content of available potassium， available nitrogen， available phosphorus， and other nutrients in the rhizosphere soil of P. polyphylla var. yunnanensis， improve soil fertility， alleviate the continuous cropping obstacles of P. polyphylla var. yunnanensis， and lay a theoretical foundation for the green and sustainable development of P. polyphylla var. yunnanensis.
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ObjectiveTo explore the forest type and soil environment suitable for Panax ginseng. MethodThe yield， quality， soil chemical properties， soil enzyme activity， and soil microbial metabolism of 9-year-old P. ginseng under different forests were investigated. ResultThe quality of P. ginseng was significantly different among forest types. To be specific， P. ginseng under the Quercus mongolica forest had the highest quality， with the total saponin content of 2.27% which was 51.89% higher than that in P. ginseng under Larix gmelinii forest. The yield of P. ginseng under Q. mongolica forest and L. gmelinii forest （30 g·m-2） was the highest， 62.5% higher than that under Betula platyphylla forest. The soil content of organic matter， Cu， and Zn， and activity of sucrase and urease under Q. mongolica forest were lower than those under other forest types. The utilization rate of D-galacturonic acid by soil microorganisms under Q. mongolica forest was higher than that under other forest types， but the utilization rate of L-phenylalanine was lower than that under other forest types. The utilization rate of 2-hydroxybenzoic acid by soil microorganisms of B. platyphylla forest was significantly lower than that under other forest types. There was a negative correlation between soil Zn and ginsenoside Rb1 and Rc， and between soil K and ginsenoside Rb2 and Rb3. Mn and Cu were positively correlated with most saponins. The results of redundancy analysis showed that the soil microorganisms using carbon sources of amino acids， esters， acids， and sugars were the main factors causing the differences in P. ginseng among different forest types. ConclusionThe yield and quality of P. ginseng under Q. mongolica forest were the best， followed by the forest with different tree species， and coming in last was the B. platyphylla forest. This study is expected to provide theoretical support for the improvement of P. ginseng yield and quality and the improvement of ecological planting technology.
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Objective:To study the change of soil environment and yield of <italic>Angelica sinensis </italic> when cultivated on the film side and and open field sides，and to explore the influence of garlic volatiles and film-side cultivation on continuous cropping <italic>A. sinensis</italic>，so as to provide some certain theoretical basis for the saying that the <italic>A. sinensis</italic> garlic intercropping mode and film-side cultivation could alleviate continuous cropping <italic>A. sinensis</italic>. Method:In this study， the effects of garlic on soil environment and yield of <italic>A. sinensis</italic> cultivated on film side and crop rotation were discussed through the determination and analysis of soil microorganism quantity，soil enzyme activity and yield of Angelica sinensis in the rhizosphere of <italic>A. sinensis</italic>. Result:The number of bacteria and actinomycetes in the rhizosphere soil of <italic>A. sinensis </italic>increased significantly， while the number of fungi decreased significantly. Among them， the number of bacteria and actinomycetes in the intercropping of <italic>A. sinensis</italic> and garlic on the film side increased by 104% and 146.89% on average as compared with that of the control （monoculture under continuous cropping open field），and the number of fungi decreased by 39.28% on average as compared with that of control group. When the enzyme activity in the rhizosphere soil was significantly increased under the condition of intercropping with garlic on the film side，the soil urease，sucrase，alkaline phosphatase and acid phosphatase activities under the intercropping of <italic>A. sinensis</italic> and gralic on the rotation film side were increased by 61.60%，51.09%，203.48% and 76.19% respectively as compared with those in control group. The yield of <italic>A. sinensis</italic> significantly increased under the condition of intercropping with garlic on the film-side，and the yield of Angelica sinensis under the rotation film-side intercropping with garlic increased by 39.37% as compared with that of control group. Conclusion:Under the mode of film-side cultivation，the interplanting of <italic>A. sinensis </italic>with garlic can change the number of soil microorganism，improve the activity of soil enzyme，improve the physical and chemical properties of soil， alleviate the obstacle of continuous cropping and guarantee the healthy growth of <italic>A. sinensis</italic> more effectively.
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Objective:To study the effects of different arbuscular mycorrhizal （AM） fungi combinations on rhizosphere soil physicochemical properties and microbial quantity in the seedlings of Paris polyphylla var. yunnanensis at different inoculation periods，so as to lay a foundation for cultivating high-quality P. polyphylla var. yunnanensis. Method:The spore density，infection rate，nutrient and enzyme activity in the soil around the roots of P. polyphylla var. yunnanensis seedlings under different AM fungi combinations and different inoculation periods were analyzed by the greenhouse pot inoculation trials and soil agrochemical analysis methods. Result:The infection rate of different AM fungi treatment groups was more than 80% in different inoculation periods，and the spore density was higher than control （CK） group in some periods. It reflected that the relationship between AM fungi and roots of Paris polyphylla seedlings was favorable. The content of nitrogen in the soil decreased，but the content of available P，available K and soil pH increased. The soil nutrients in the cultivar one-year seedlings and wild seedlings were higher. The total number of soil microorganisms showed that bacteria>actinomycetes>fungi. The cultivar two-year seedlings with AM fungi combinations of S3，S5 and S8 had better soil structure and higher biomass carbon content. The growth rates of phosphatase and protease activity were higher in the soil，but catalase activity was lowest. In the treatment groups S2，S3，S4，S5 and S6，the soil enzyme activities of the wild seedlings and one-year-old seedlings were best. Conclusion:Different AM fungal treatment groups and different inoculation periods had certain effects on rhizosphere soil physicochemical properties and microbial quantity in the seedlings of P. polyphylla var. yunnanensis， which provided a technical basis for the cultivation of P. polyphylla var. yunnanensis.
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Objective:To investigate the effect of different arbuscular mycorrhizal （AM） fungi combinations on the rhizospheric environment of Paris polyphylla var. yunnanensis. Method:The different combinations of 12 arbuscular mycorrhizal （AM） fungi species were inoculated to the seedlings P. polyphylla var. yunnanensis planted in the sterilized soil under the condition of room temperature to investigate their infection abilities and effects on the root activity，soil nutrient contents，enzyme activities and microbial community structure of P. polyphylla var. yunnanensis rhizospheric environment. Result:The inoculation of exogenous AM fungi can regulate the spore densities and infection rate of P. polyphylla var. yunnanensis rhizosphere AM to improve the root activity， the exogenous AM fungi can also regulate the nutrient contents in the rhizosphere soil，increase the contents of total glomalin and easily extracted glomalin，increase the abilities of P. polyphylla var. yunnanensis to absorb the available N，P and K，and increase the enzyme activities in the rhizosphere soil， improve the microbial community structure， and improve the rhizospheric environment of P. polyphylla var. yunnanensis by increasing the bacteria/fungi and bacteria/actinomycetes quantity ratios and reducing the fungi/actinomycetes quantity ratio. Conclusion:Different AM fungal treatment groups had certain effects on the physicochemical properties and microbial community structure of the rhizosphere soil of P.polyphylla var. yunnanensis，which provided a technical basis for the cultivation of P. polyphylla var. yunnanensis.
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The effects of four kinds of different plant populations on the soil physical and chemical properties and soil enzyme activities of Salvia miltiorrhiza were analyzed by setting up four kinds of mixed planting groups, such as S. miltiorrhiza and Cassia obtusifolia, Capsicum annuum, Perilla frutescens and Zea mays. And through the root isolation treatment, we preliminarily explored the formation mechanism of the four kinds of matching plants of soil physical and chemical properties and soil enzyme activities of S. miltiorrhiza, and chose the matching plants suitable for the establishment of the compound population with S. miltiorrhiza,and provided the basis for constructing high efficiency compound planting pattern of S. miltiorrhiza. The results showed that there were significant differences in soil physical and chemical properties and soil enzyme activitiesof Salvia miltiorrhiza in different compound population mixed.The combination of C. obtusifolia, P. frutescens, Z. mays and S. miltiorrhiza mixed planting were all reduced the soil cation exchange capacity and soil enzyme activities, and increased the soil electric conductivity. The compound planting of P. frutescens and S. miltiorrhiza increased the soil cation exchange capacity and soil enzyme activities, and reduced the soil electric conductivity. Therefore,The compound planting population of P. frutescens and S. miltiorrhiza is conducive to improve soil physical and chemical properties and increase soil microbial activity, which is the best collocation species of S. miltiorrhiza.
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Study on 5 effective components and 6 soil enzyme activities of 2 different growth patterns, analyse the dates with the canonical correlation analysis, In order to reveal the relations between the effective components and soil enzyme activities. The result showed that they had a great relation between the effective components and soil enzyme activities, the activity of the same enzyme in humus soil was higher than that in farmland soil. Growth pattern of farmland soil, if the invertase and phosphatase activity were too high, which would inhibit the accumulation of total ginsenoside, water-miscible total proteins and total amino acid; Growth pattern of humus soil, if the invertase, urease and phosphatase activity were too high, which would inhibit the accumulation of total ginsenoside and the total essential oils. Integral soil enzyme activity can be used as a index of soil quality, which, together with other growth factors. The appropriate enzyme activity can accelerate the circulation and transformation of all kinds of material in the soil, improve effectively components accumulation.
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Aims: To study the effect of various doses of tetracycline (TC), oxytetracycline (OTC) and chlortetracycline (CTC) on the enzymatic (DHA, acid phosphatase, alkaline phosphatase, urease and catalase) activity in sewage amended and un-amended alluvial soil. Methodology: A laboratory incubation study was conducted during 2012-2013 on an Aligarh farm alluvial soil. The enzymatic activity was studied in presence of various doses of three tetracycline antibiotics in soil; soil amended with sewage sludge; and mixture of sewage sludge and tetracyclines at different time intervals [(0 (4h), 7, 14, 21, 35, 56, 70,91d]. Results: Activity of all the studied enzymes was significantly inhibited for up to 14-21 days of incubation (14 d for DHA and acid phosphatase, 21 d for alkaline phosphatase, urease and catalase) and thereafter inhibition got weaker. The activity of all the studied enzymes decreased with increase in the doses of tetracyclines. Higher enzymatic activity was observed in sewage sludge amended soil than in the un-amended soil. Tetracyclines in presence of sewage sludge were found to have no appreciable effect on enzymatic activities. Conclusions: Dehydrogenase, acid and alkaline phosphatase, urease and catalase activity in tetracycline free soil was superior to soil containing antibiotics in the period of 2-3 weeks of incubation. The inhibition of soil enzyme activity was directly proportional to tetracycline concentration. In presence of sewage sludge, the studied enzymes activity initially increased up to 3 weeks and decreased thereafter. In presence of sewage sludge and antibiotics, the activity of enzymes remains almost unchanged. The activity of studied enzymes in soil was positively correlated to soil organic content.
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Phosphogypsum (PG) is produced as a solid waste from phosphatic fertilizer plants. The waste slurry is disposed off in settling ponds or in heaps .This solid waste is now increasingly being used as a calcium supplement in agriculture. This study reports the effect of PG amendment on soil physico chemical properties, bacterial and fungal count and activities of soil enzymes such as invertase, cellulase and amylase over an incubation period of 28 days. The highest mean percent carbon loss (55.98%) was recorded in 15% PG amended soil followed by (55.28%) in 10% PG amended soil and the minimum (1.68%) in control soil. The highest number of bacterial colonies (47.4 CFU g-1 soil), fungal count (17.8 CFU g-1 soil), highest amylase activity (38.4 ?g g-1 soil hr-1) and cellulase activity (38.37 ?g g-1 soil hr-1) were recorded in 10% amended soil . Statistically significant difference (p<0.05) has been recorded in the activities of amylase and cellulase over the period of incubation irrespective of amendments. Considering the bacterial and fungal growth and the activities of the three soil enzymes in the control and amended sets, it appears that 10% PG amendment is optimal for microbial growth and soil enzyme activities.