Improved nutrient status affects soil microbial biomass, respiration, and functional diversity in a Lei bamboo plantation under intensive management
Improved nutrient status affects soil microbial biomass, respiration, and functional diversity in a Lei bamboo plantation under intensive management
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DOI：
10.1007/s11368-016-1603-2
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发表时间：
2017-04-01
影响因子：
3.6
通讯作者：
Li, Zhongpei
中科院分区：
文献类型：
--
作者：
Liu, Ming;Liu, Jia;Li, Zhongpei
雷竹人工林为获得较高的产量，经常采用施肥和有机覆盖等集约经营措施。然而，这种管理下的土壤微生物特性的响应以及关键影响因素仍然不确定。以雷竹种植园为研究对象，分析了集约经营条件下土壤养分变化与微生物量、活性和功能多样性的主要影响因素，研究了不施肥（对照）、化学施肥（CF）和有机化学施肥+有机覆盖（CFOM + M）3种处理下土壤微生物量、活性和功能多样性的变化。测定了土壤有机碳、溶解性有机碳、全氮、速效氮、速效磷、速效钾含量。还分析了微生物生物量碳（MBC）、基础呼吸和矿化。采用BIOLOGY方法分析了微生物的群落水平生理剖面（CLPP），以评价微生物的功能多样性和碳源利用模式。通过主成分分析（PCA）、主响应曲线（PRC）、相关性分析、回归分析和冗余分析（RDA）等方法，研究了土壤有机碳、全氮、速效磷和速效钾的变化规律，结果表明：CFOM + M > CF >对照。而C/P和N/P比值则呈现相反的趋势。微生物菌量和呼吸作用不受影响，但微生物商和代谢商在集约化管理下有所下降。McIntosh多样性指数在CFOM + M中较高。主成分分析表明，CFOM + M中微生物对大多数碳源的利用能力较强。丝氨酸的利用较弱，表明CFOM + M的养分缺乏得到缓解。CLPP的PRC表现出显着的处理效果，丝氨酸的利用敏感地响应于整个培养时间的营养状况。RDA结果表明，全N、速效N、全K和C/P是影响微生物群落利用C源的主要因素，施肥结合有机覆盖提高了雷竹种植园土壤养分、微生物生物量和呼吸强度。丰富的养分也提高了集约化管理下微生物对碳源的利用效率。N、K和C/P的变化可能导致微生物向不同的生活策略转变，并决定了微生物群落C源利用模式的变化。
Intensive management, such as fertilization and organic mulching, is applied frequently in Lei bamboo (Phyllostachys praecox) plantations to achieve higher production in subtropical China. However, responses as well as key impact factors of soil microbial properties under such management remain uncertain. We analyzed the relationships between nutrient changes and microbial properties and assessed the main factors determining microbial biomass, activity, and functional diversity in soils under intensive management in a Lei bamboo plantation.Soil samples of treatments of no fertilization (control), chemical fertilization (CF), and chemical and organic fertilization combined with organic mulching (CFOM + M) were taken before mulching. The soil organic carbon (SOC), dissolved organic carbon, and total and available nitrogen (N), phosphorus (P), and potassium (K) were measured. Microbial biomass carbon (MBC), basal respiration, and mineralization were also analyzed. Community level of physiological profile (CLPP) of microorganisms was analyzed by BIOLOG method to estimate the functional diversity and carbon (C) source utilization patterns of microbes. Principal component analysis (PCA), principal response curve (PRC), correlation analysis, regression analysis, and redundancy analysis (RDA) were performed to clarify changes in variables and determine the factors influencing microbial properties.SOC and total and available N, P, and K increased as follows: CFOM + M > CF > control. However, C/P and N/P ratios showed an opposite trend. MBC and respiration were not affected, but microbial quotient and metabolic quotient declined under intensive management. McIntosh diversity index was much higher in CFOM + M. The PCA showed that microorganisms in CFOM + M had a stronger ability to use most C sources. Weaker utilization of serine indicated an alleviation of nutrient deficiency in CFOM + M. PRC of CLPP showed a significant treatment effect and that utilization of serine sensitively responded to nutrient status over the whole incubation time. RDA showed that total and available N, total K, and C/P were the main factors influencing utilization of C sources by microbial communities.Fertilization combined with organic mulching increased soil nutrients, microbial biomass, and respiration in a Lei bamboo plantation. Abundant nutrients also increased C source use efficiency of microorganisms under intensive management. Changes of N and K and C/P might have led to a shift in microorganisms toward a different life strategy and determined the change in C source utilization patterns of microbial communities.