| In this study, Coal Mining Subsidence reclaimed land in Luo jianggou village, Wangqiao Town, Xiangyuan County, Changzhi City was selected as the research object and a field experiment was carried out to study the effects of different treatments in chemical fertilizers, organic manure and phosphorus bacterial fertilizers on microbial diversity and phosphorus effectiveness in coal mining subsidence soil with different reclamation time(la,2a,5a and 6a respectively). The results showed that:(1) Soil microbial carbon and nitrogen contents in different reclamation years were increased significantly for fertilization. The highest microbial organic carbon and nitrogen were observed in treatments of manure and phosphorus bacterial fertilizers cooperation with 1a and 2a reclamation, while the maximum contents these were got in treatments of manure, fertilizer and phosphorus bacterial fertilizers cooperation with 5a and 6a reclamation. The combination of manure and phosphorus bacterial fertilizers could increase soil microbial bacteria providers and accelerate soil aging.(2) Soil activities of alkaline phosphatase, urease, invertase increased with the increase of soil reclamation years. The highest soil activities of alkaline phosphatase, urease were observed in the combination of manure and phosphorus bacterial fertilizers in 1a and 2a reclamation areas. In 5a and 6a reclamation areas, the maximum of alkaline phosphatase, urease activities were observed in treatments of manure, fertilizer and phosphorus bacterial fertilizers cooperation. Meanwhile, catalase activity decreased with the increase of soil reclamation years, and the considerable reduction were observed in combination of manure and phosphorus bacterial fertilizers, as well as in treatments of manure, fertilizer and phosphorus bacterial fertilizers cooperation. Correlation analysis of microbial organic carbon and nitrogen and activities showed that reclamation soil microbial carbon and nitrogen, microbial quotient had significantly positive correlation with alkaline phosphatase, urease, sucrase activities and had significantly negative correlation with catalase activity.(3) Soil microbial community structure diversity of different reclamation years were researched by phospholipid fatty acid technology(PLFA), and the results showed that the maximal values of total PLFA, bacterial PLFA, fungi PLFA, as well as PLFA of gram positive and negative bacteria were observed in the combination of manure and phosphorus bacterial fertilizers in 1a and 2a reclamation areas and in manure, fertilizer and phosphorus bacterial fertilizers cooperation in 5a and 6a reclamation areas. There were no significant differences of bacterial/fungi in the combination of organic and inorganic manure and phosphorus bacteria fertilizer, as well as in manure and phosphorus bacterial fertilizers cooperation. Compared with the treatments of chemical nitrogen fertilizer and CK, the bacterial/fungi could be improved by the cooperation of manure and phosphorus bacterial fertilizers. The differences of composition and structure were slight between the application of phosphorus bacteria fertilizer and no phosphorus bacteria fertilizer in la reclamation areas. There were great composition and structure differences between the combination of manure and phosphorus bacterial fertilizers and phosphorus bacteria fertilizer in 2a reclamation areas. Compared with no phosphorus bacteria fertilizer treatments, there were obvious differences in combination of organic and inorganic manure and phosphorus bacteria fertilizer, as well as in manure and phosphorus bacterial fertilizers cooperation.(4) The results of Iliumina Miseq high-throughput sequencing technology showed that most abundant bacterial communities were observed in the treatment of organic and inorganic manure and phosphorus bacteria fertilizer combination in 5a reclamation areas, and the bacterial community in Actinobacteria and Proteobacteria accounted for the largest proportion. Compared with the control, the highest Chaol index and Shannon-Wiener index showed organic manure, chemical fertilizer and phosphorus bacteria fertilizer combination. Diversity index were greater in phosphorus bacteria fertilizer treatment than no phosphorus bacteria fertilizer. PCA analysis found that there were no significant differences of bacterial communities during the treatments of chemical fertilizer, organic manure+chemical fertilizer and organic fertilizer+ phosphorus bacteria fertilizer.(5) Soil microbial functional diversity in 1a and 5a reclamation areas were analyzed using Biolog microplate technique. The results found that the change sequence of microbial community AWCD were organic manure+ chemical fertilizer+ phosphorus bacteria fertilizer organic fertilizer> organic manure+ chemical fertilizer> organic fertilizer+ phosphorus bacteria fertilizer> organic fertilizer> chemical fertilizer> chemical fertilizer+ phosphorus bacteria fertilizer>CK. The highest Shannon index, Shannon evenness index, McIntosh index and McIntosh evenness index were found in the treatment of organic manure+ chemical fertilizer+ phosphorus bacteria fertilizer. It could be seen from the different carbon source utilization that the carbon source utilization ability of soil microbial biomass were maximum in in combination of organic and inorganic manure and phosphorus bacteria fertilizer. The main carbon source utilization of soil microbial carbon were amino acids and carboxylic acids in the first reclamation year, after the continuous reclamation 5 years, the main carbon source were sugar, amino acids and carbon source.(6) The order of total phosphorus content influenced by different reclamation years was chemical fertilizer> organic manure> chemical fertilizer and organic fertilizer. The difference between the application of phosphorus bacteria fertilizer and no phosphorus bacteria fertilizer was not significant. The highest soil available phosphorus content in 2a and 5a reclamation soil were observed in the treatments of organic fertilizer and phosphorus bacteria fertilizer combination which were increased by 7.97%?-14.56% compared with the single application of organic fertilizer treatments. The classification results of Hedley-P showed that:compared with chemical fertilizer treatment, the application of organic manure+ phosphorus bacteria fertilizer and organic manure+ chemical fertilizer+ phosphorus bacteria fertilizer could significantly increased soil H2O-P, NaHCO3-P, NaOH-P, HCl-Pi, HCl-Po content and reduced the content of HCl-Pi and residual-P. There were no significant differences during the organic fertilizer treatments. The contents of HCl-Pi, residual-P in the application of organic manure and phosphorus bacteria fertilizer were respectively decreased by 1.35%?3.88% and 2.63%?9.93% compared with the application of organic fertilizer and these in treatment of organic manure+chemical fertilizer+ phosphorus bacteria fertilizer were respectively decreased by 2.77%-2.89% and 2.18%?8.19% compared with in organic manure+ chemical fertilizer treatments. Path analysis of soil Olsen-P and Hedley-P indicted that the indirect influence of soil NaHCO3-Pi by direct interaction with the NaOH-Pi, H2O-Pi, NaHCO3-Po could change Olsen-P. NaHCO3-Pi content can be used as a main index to determine the phosphorus nutrition in reclamation soil.(7) The correlation coefficients of soil phosphorus isothermal adsorption equation of Langmuir were between 0.9331 and 0.9950(P<0.001), and it could be fitted with the equation of reclamation. The order of adsorption constants(K), soil phosphorus (Xm) and the maximum buffering capacity of soil (MBC)in 2a reclamation were roughly organic manure+ phosphorus bacteria fertilizer< organic fertilizer+ chemical fertilizer+ phosphorus bacteria fertilizer< chemical fertilizer +phosphorus bacteria fertilizer, while those in 5a reclamation were roughly organic fertilizer+ chemical fertilizer+ phosphorus bacteria fertilizer< organic manure+ phosphorus bacteria fertilizer< chemical fertilizer +phosphorus bacteria fertilizer. The highest P desorption and average desorption rate were observed in organic manure+ phosphorus bacteria fertilizer in 2a reclamation areas and in organic manure+ chemical fertilizer+ phosphorus bacteria fertilizer in 5a reclamation areas,respectively.(8) The correlation analysis between soil microbial diversity and phosphorus validity showed that soil microbial biomass carbon(MBC), microbial biomass nitrogen(MBN), microbial quotient (MBC/MBN), alkaline phosphatase, urease, invertase activity and available phosphorus were positively correlated; soil microbial PLFA, bacterial community diversity index, functional diversity indexes had significant positive correlation with soil available phosphorus content. |
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