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利用磷脂脂肪酸分析法和微平板测定法研究红壤荒地开垦为水田耕种20年后,不同施肥处理条件下土壤微生物群落结构和功能多样性变化,并分析土壤微生物学指标与土壤养分含量变化的关系。结果表明,与不施磷处理相比,施磷处理的水稻年产量、土壤有机碳、全氮、碱解氮、全磷和速效磷含量平均提高了196.6%、11.4%、19.4%、14.0%、100.6%和300.1%;而与未施有机肥处理相比,施有机肥处理上述各指标平均提高了85.4%、23.8%、25.0%、15.0%、38.6%和86.8%。与对照相比,施用磷肥和施用有机肥处理的微生物总磷脂脂肪酸(PLFA)含量提高了13.6%~68.9%。磷肥和有机肥的施用也提高了各菌群微生物的PLFA含量。不同施肥处理土壤微生物群落平均吸光度(AWCD)值、Shannon指数、Simpson指数和Mc Intosh指数分别为0.17~0.30、2.79~3.03、0.93~0.94和1.46~2.27。磷肥和有机肥的施用提高了微生物群落的AWCD值和功能多样性指数。主成分分析表明,施用磷肥和施用有机肥的处理微生物群落结构和碳源利用方式明显区别于对照、单施氮肥和施用氮钾肥的处理。逐步回归分析显示,有机碳、全磷、全氮和速效磷是影响土壤微生物群落结构和功能多样性的关键因素。磷肥和有机肥的施用有利于促进土壤微生物活性和多样性,提高土壤生物功能和生产力。
Phospholipid fatty acid analysis and microtiter plate assay were used to study the changes of soil microbial community structure and functional diversity under different fertilization treatments after reclamation of paddy field from red earth to paddy field for 20 years. The relationship between soil microbial indices and soil nutrient content was also analyzed. The results showed that annual phosphorus, total organic carbon, total nitrogen, total nitrogen, total phosphorus and total phosphorus were increased by 196.6%, 11.4%, 19.4%, 14.0% , 100.6% and 300.1% respectively. Compared with no organic fertilizer treatment, the above indexes of organic fertilizer treatment increased by 85.4%, 23.8%, 25.0%, 15.0%, 38.6% and 86.8% on average. Compared with the control, the content of total phospholipid fatty acid (PLFA) of the microorganisms treated with phosphate fertilizer and organic manure increased by 13.6% -68.9%. The application of phosphate fertilizer and organic fertilizer also increased the PLFA content of each group of microorganisms. The mean value of soil microbial community average absorbance (AWCD), Shannon index, Simpson index and Mc Intosh index were 0.17-0.30, 2.79-3.03, 0.93-0.94 and 1.46-2.27, respectively. The application of phosphate fertilizer and manure increased the AWCD value and functional diversity index of microbial communities. Principal component analysis showed that the microbial community structure and carbon source utilization pattern of applying phosphate fertilizer and applying organic fertilizer were obviously different from those of the control, applying nitrogen fertilizer alone and applying nitrogen and potassium fertilizer. Stepwise regression analysis showed that organic carbon, total phosphorus, total nitrogen and available phosphorus were the key factors affecting the microbial community structure and functional diversity. The application of phosphate fertilizer and organic fertilizer is conducive to promoting soil microbial activity and diversity, and improving soil biological function and productivity.