| Phyllostachy edulis is an important forest resources and are widely distributed in southern China. Itbelongs to the type of culm and shoot-producing bamboo species with the advantages of high economicand ecological values. It is one of the main ways to increase income of foresters. The impropermanagement idea and mode of predatory management resulted in series problem of poor managementbenefit, low productivity and soil quality degradation. The urgent problems to solve is how to maintainhigh yield and high quality in P. edulis forest management. The aspects of nutrient management studiesof P. edulis have been widely deployed, but the ecological processes in rhizosphere micro-domain werelack of study for one system characteristic of bamboo scourge and root caused more difficult tocorrespond plant and soil. In this paper, by taking P. edulis forest under three different fertilizationtreatments and the control in forest farm of Guanshan, Yongfeng city, Jiangxi province as the researchobject, using conventional methods, phospholipids fatty acid (PLFA) method, and the approach ofspace-time substitute, the following aspects were studied.(1) Effect of fertilization on soil nutrientcontent and enzyme activity in rhizosphere and non-rhizosphere soil of P. edulis with different ages.(2)Effect of fertilization on soil microbial community structure in rhizosphere and non-rhizosphere soil ofP. edulis with different ages.(3) Effect of fertilization on soil microbial community diversity inrhizosphere and non-rhizosphere soil of P. edulis with different ages.(4) Effect and correlation offertilization on soil enrichment ratio in rhizosphere soil of P. edulis with different ages.(5) Thecorrelation of soil microbial community with soil nutrient and enzyme activity. The main purpose wasto by research on microbial ecological characteristics in rhizosphere soil with different fertilizationtreatments to provide theoretical reference for precision fertilization and nutrient management of P.edulis forest. The main results were as follows:(1) The effects of different fertilization treatment on soil nutrient content and enzyme activity inrhizosphere and non-rhizosphere were different. The effect of45%slag fertilizer and39%slag fertilizeron nutrients content in rhizosphere soil of P. edulis had similartity. Special fertilizer for bamboo asfast-acting for the effect on nutrients content in rhizosphere soil of P. edulis had similarity with thecontrol treatment. With age increased, the change of different contrients content in rhizoshere soil werenot the same.The enzyme activities in rhizosphere soil were generally greater than in non-rhizosphere soil. Withthe age increased, the protease in rhizosphere soil showed the trend as “down-up”, soil urease activitywas generally increased, phosphatase activity was generally decreased, the trend of invertase activitywas not obvious.(2) Soil PFLAs species were measured for80species with C chain length from12to20, indicatingdifferent groups of microorganisms included bacteria, fungi, actinomycetes, protests and others.Microbial PLFAs biomarker was31kinds which bacteria, fungi, actinomycetes and protests biomarkerwere22kinds,4kinds,4kinds and1kinds respectively. In rhizosphere, total PLFAs was highest in 39%slag fertilization treatment (10892.62ng g-1soil), followed by special fertilization for bambootreatment (9256.03ng g-1soil),45%slag fertilization treatment (8976.53ng g-1soil) and CK (6945.15ng g-1soil). In non-rhizosphere soil, total PLFAs showed the trend as45%slag fertilizationtreatment>39%slag fertilization treatment>special fertilization for bamboo treatment>CK. BacteriaPLFAs was highest among3kinds of microflora. Fungi and actinomycetes PLFAs fairly, G+PLFAs>G-PLFAs.(3) Microbial community structure of PLFAs in rhizosphere and non-rhizosphere soil with differentfertilization can classified into3categories through cluster analysis and principal component analysis.Principal component1(PC1) explained87.6%of the variable difference, principal component2(PC2)explained5.5%of the variable difference. It can concluded that different fertilizers had greater impacton soil microbial community structure. Principal component analysis of PLFAs species showed thatprincipal component1(PC1) and2(PC2) explained73.4%and13.6%of soil microbial community, thetwo main ingredients to reach87.6%in total and can better to reacted soil microbial communitystructure.(4) Soil nutrient enrichment in rhizosphere soil had a greater effect on enzyme and microorganismenrichment. The higher correlation between soil nutrient and microorganism enrichment, soilmicroorganism and enzyme enrichment, soil nutrient and enzyme enrichment were mainly caused bysoil organic matter and bacteria enrichment, total PLFAs and invertase and urease enrichment, totalpotassium and phosphate enrichment had closely relationship respectively. It can illustrated that soilorganic matter enrichment had great impact on bacteria enrichment, invertase and urease enrichmenthad a certain impact on total PLFAs enrichment and total potassium enrichment had a certain impact onphosphate enrichment.(5) The relationship between soil microflora and soil nutrient and enzyme activity in rhizosohereand non-rhizosphere soil were similar. Total potassium had greater effect on soil microbial communityboth rhizosphere and non-rhizosphere soil. Organic matter had high correlation with soil microflora,followed by available nitrogen, but total potassium and available potassium had negative correlationwith soil microflora. Total phosphorus and soil microflora had weak negative correlation in rhizospheresoil and a certain positive correlation in non-rhizosphere soil. There existed a certain positive correlationbetween invertase, phosphatase, urease, catalase and soil microflora respectively. While the correlationbetween protease and microflora was poor. Urease had a higher correlation with soil microflora inrhizosphere soil, while it was invertase in non-rhizosphere. |
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