Effects Of Revegetation On Soil Microbial Characterstics During Nitrogen Mineralization In Southern Ningxia

After ten years reforestation work in Southern Ningxia Mountain, vegetation has been effectively recovered, the ecological environment has been significantly improved, physical, chemical and biological properties of the soil are improved. However, the main nutrient of different vegetation restoration under way to play an important role in the interaction between plants and soil microbes in the process required for plant growth- nitrogen mineralization during the dynamic characteristics unclear.. Therefore, in order to reveal the effects of different vegetation restoration on microbial diversity and activity of soil nitrogen mineralization in for rich microbial ecology theoretical conversion of nitrogen in terrestrial ecosystems, and promote regional vegetation restoration provide a theoretical basis. In this paper, agricultural land maize as a control, select the typical vegetation of southern Ningxia mountainous area three grassland restoration under way: natural grass, artificial turf and natural grass recovery; three plantations in: korshinskii hickory and wild apricot; and Wild Apricot and alfalfa grass was planted under intercropping 7 soil as the research object, the use of high-throughput sequencing clear community structure under different vegetation and soil microbial diversity on the basis, on the laboratory and in situ mineralization mineralization 56 d 2 a test of Study on the microbial biomass, ammonifier, metabolic activity and enzyme activity variation characteristics of soil mineralization process, and to explore the influencing factors. The main conclusions are as follows:(1) Southern Ningxia Mountain 5 planting soil microbial diversity are greater than fungi, bacteria belonging to the measured 29, 77 classes, 137 orders, 253 families, 378 genera and 686 kinds, Proteobacteria of Bacillus the largest number, accounting for 2.1 to 11.5%, and the abundance of plantation land(7.5%)> agricultural land(5.4%)> grassland(4.7%); the highest diversity in alfalfa field hickory to a minimum. Fungi belonging to 28, 45 classes, 71 orders, 92 families, 109 genera, 114 kinds; advantages fungi Ascomycota and Basidiomycota, the dominant genera Gibberella(Fusarium), the total number of fungi 1.2 to 14.1%; diversity index in artificial meadow> farmland> natural grassland> plantation land.(2) the range of variation of soil microbial biomass carbon is 8.2 ~ 221.1mg / kg, half buried mineralization, decreased 52.2% ~ 94.2%; greater than in spring and autumn, up 26.6%-215.1%; the fall pipe 1 a, the outer tube is higher than 1.5 to 5.9 times the inner tube, pipe 2 a, the outer tube of 1.3 to 6.7 times higher than the inner tube; variation range of microbial biomass nitrogen was 12.0 ~ 49.0mg/kg, half buried mineralization increased by 35.6% ~ 210.1%, more than in spring and autumn, up from 5.4% to 105.1%; higher than the fall pipe 2 a 1 a, higher than the 1.0 to 1.8 times. Ammonifiers 0.21×104~3.15×104 cfu?g-1, Caragana> natural grassland> farmland> artificial meadow> Mountain Peach after incubation decreased 26.7% ~ 85.1%. Situ borehole 1 a spring than autumn borehole 1 a microbial biomass carbon and nitrogen were generally higher indoor simulation mineralized natural grassland> artificial meadow> farmland, mountain peach> Caragana forest> farmland; microorganism-mediated carbon-nitrogen ratio 0.96 to 11.9 in spring borehole 1 a(3.9~11.2) is greater than the fall pipe 1 a(1~3.9), with the increase of time of increased mineralization mineralization 2 a, ranged from 5.3-7.6. Microbial quotient between 0.32% ~ 3.54%, with the increase of mineralization time increases, indicating the recovery process Plantation soil carbon accumulation in the process, to restore the natural grass mineralization greater than accumulation. Woodland microbial carbon season’s Sensitive Index, while in the grass microbial biomass nitrogen is more sensitive to seasonal variation.(3) Laboratory simulation found that soil microbial respiration rate ranged from 14.7~184.3 mg ? kg-1 ? d-1, larger changes significantly decreased 61.8%~72.4% in the first nine days, the performance of different woodland tree> shrub in grassland natural grassland> artificial turf, are greater than agricultural land; situ mineralization of soil respiration rate was 118.5~313.56 mg ? kg-1 ? d-1, higher than the indoor simulation training, tube mineralization 0.5 a, respiration rate increase of 49.3%~105.8%, 1 a higher than the fall pipe 2 a, up 25.1%~56.4%; indoor simulation metabolic quotient(0.21 to 1.78) less than in situ mineralization culture(1.0 to 17.7), indoor show simulation of microbial utilization of carbon mineralization of low mineralization1 a greater than 2 a, 2 to 11.9 times higher than the pipe outside in October is 1.1 to 5.4 times in August, and autumn(October) than in spring(April) higher than the 1.2 to 3.6 times; net mineralization rate only korshinskii mineralization in the early(0-28 d) there has been a negative, other vegetation throughout the period of mineralization are greater than the cumulative process in mineralization. Microbial respiration and soil temperature was significantly positively correlated with soil moisture less relevant, the temperature is seasonal variation of soil respiration rate of the main controlling factor.(4) Protease grassland soils as natural grassland>artificial grassland>natural grassland restoration, Caragana>Mountain Peach>wild apricot; indoor simulation ranged from 1.56 ~ 11.39 ug/g, cultivation dropped 15.0 %~72.2 % at the end of autumn after the pipe is significantly greater than the spring 1 a pipe 1 a, generally less than 1.5 a spring pipe spring pipe 1 a. Asparagine activity for the natural restoration grassland> natural grassland> artificial turf, Caragana> wild apricot> Mountain Peach. Indoor simulated conditions ranged from 0.04 ~1.85 mg/g, a significant increase in the first 28 d, an increase of 2.7 to 24.5 times, asparagine activity decreased in the fall, buried 2 a minimum. Protease soil and soil temperature and moisture, organic carbon, total nitrogen, microbial biomass carbon and nitrogen, and pH were significant correlation between the level of linear correlation with the microbial biomass carbon and ammonium nitrogen; asparagine soil activity and soil temperature, pH and organic carbon was significantly correlated with ammonium linear.