细菌肥料对湿地松幼龄林生长及土壤性质的影响

Effects of Bacterial Fertilizers on the Growth and Soil Properties of Pinus elliottii Young Stand

[目的]通过研究细菌肥料对湿地松幼龄林生长及对土壤养分、微生物群落功能多样性和酶活性的影响,为细菌肥料对湿地松土壤改良的应用提供参考,以期在促进湿地松生长及改良土壤的同时保持良好的生态环境。[方法]2016年7月在江西省分宜县山下林场采用随机区组设计,设置3个区组,3个处理,分别为细菌肥料处理、基质对照处理及不添加任何肥料的空白对照处理。2017年11月测量湿地松的株高和地径,采用5点取样法采集土壤样品,测定土壤密度、毛管孔隙度、非毛管孔隙度、最大持水量、有机质、有效磷、速效钾、水解性氮以及过氧化氢酶、磷酸酶、蔗糖酶和脲酶活性,用Biolog-ECO板分析微生物群落功能多样性。[结果]细菌肥料显著促进了湿地松幼苗株高和地径的增长,空白对照、基质对照处理和细菌肥料处理地径的相对增长量分别为98.27%、105.53%和123.09%,株高的相对增长量分别为55.69%、66.56%和85.18%,细菌肥料处理和基质对照处理均降低了土壤密度,增加了土壤毛管孔隙度、非毛管孔隙度以及最大持水量,改善了土壤物理性质,但细菌肥料处理的作用更显著。细菌肥料和基质对照均提高了湿地松土壤的有机质、有效磷、水解性氮以及速效钾含量,但细菌肥料处理与空白对照处理之间在4种养分含量上均存在显著性差异,而基质对照与空白对照之间只在有机质含量上存在显著性差异。细菌肥料处理显著提高了土壤磷酸酶、过氧化氢酶、蔗糖酶以及脲酶活性,细菌肥料还使土壤微生物群落代谢活性、对6类碳源(碳水化合物类、氨基酸类、羧酸类、多聚物类、酚酸类和胺类)的利用能力以及土壤微生物群落的Shannon多样性指数(H)、Simpson优势度指数(D)、Pielou均匀度指数(J)和丰富度指数(S)显著提高,基质对照也促进了上述指标的升高,但效果并不显著。[结论]细菌肥料处理和基质对照处理均可以促进湿地松幼苗的生长,提高湿地松土壤有机质、有效磷、速效钾以及水解性氮的含量,同时使土壤过氧化氢酶、磷酸酶、蔗糖酶以及脲酶活性升高,提高土壤微生物多样性、均匀度、丰富度以及优势度指数,提高了微生物对单一碳源的利用能力以及代谢活性,但细菌肥料的作用效果更为显著,基质对照的作用效果并不显著。

[Objective] The effects of bacterial fertilizers on the growth of pine young stand, microbial community functional diversity, enzyme activities and soil nutrient content were studied to provide references for the application of bacterial fertilizers, and to promote the growth of Pinus elliottii forest and improve soil while maintaining a good ecological environment.[Method] Three blocks and three treatments (bacterial fertilizer treatment, matrix control treatment and the blank control treatment adding no fertilizer) for every block were set up in July 2017 by random block design in Fenyi County, Jiangxi Province. In November 2017, The tree height and diameter of P. elliottii were measured, the soil density, capillary porosity, non-capillary porosity, maximum water-holding capacity, organic matter, available phosphorus, available potassium and alkaline nitrogen were measured by 5-point sampling, and the soil catalase, phosphatase, sucrase and urease activity were analyzed. The functional diversity of microbial community was analyzed by Biolog-ECO plate.[Result] The bacterial fertilizer significantly promoted the growth of P. elliottii seedlings, the growth rate of ground diameter of the blank control treatment, matrix control treatment and bacterial fertilizer treatment were 98.27%, 105.53% and 123.09%, respectively, and the growth rate of tree height were 55.69%, 66.56% and 85.18%. The bacterial fertilizer treatment and matrix control treatment reduced soil density, increased soil capillary porosity, non-capillary porosity and maximum water-holding capacity, and improved soil physical properties, however, the effect of bacterial fertilizer treatment was more significant. The contents of organic matter, available phosphorus, available potassium and alkaline nitrogen in soil increased by matrix control treatment and bacterial fertilizer treatment, and there was significant difference in all of the 4 nutrient contents between the bacterial fertilizer treatment and the blank control treatment, while there was significant difference between the matrix control and the blank control only in the organic matter content. Bacterial fertilizer treatment significantly increased the activities of soil phosphatase, catalase, sucrase and urease, it also promoted the soil microbial community activity, the utilization capacity of six kinds of carbon sources (carbohydrates, amino acids, carboxylic acids, polymers, phenolic acids and amines), and contributed to Shannon’s diversity index, Simpson’s dominance index, Pielou’s evenness index and richness index of soil microbial community. The matrix control also contributed to the increase of the above-mentioned indicators, but the effect was not significant.[Conclusion] Bacterial fertilizer and matrix control can promote the growth of P. elliottii seedlings, improve soil organic matter, available phosphorus, available potassium and alkaline nitrogen content in soil, and increase the activities of catalase, phosphatase, invertase and urease. In addition, they improve soil microbial diversity, evenness, abundance and dominance index, and improve the utilization and metabolic activity of microorganisms to single carbon sources. The effect of bacterial fertilizer is more significant, while the effect of matrix control is not significant.