东北黑土区不同土地利用方式下农田土壤微生物多样性

为探究黑龙江省黑土区不同土地利用方式下土壤微生物多样性，该研究主要采用Biolog Eco微平板法，以荒地为对照，研究了黑龙江省中部和西南部黑土区玉米、水稻、大豆及土豆4种不同土地利用方式下土壤微生物多样性的变化。结果表明：1）可培养细菌的数量从大到小依次为土豆、水稻、大豆、玉米、荒地，但群落Shannon-Wiener多样性指数从高到低依次为：荒地（2.18）、玉米（2.11）、土豆（2.00）、水稻（1.73）、大豆（1.49）；2）不同利用方式下黑土区微生物碳源利用程度大致随培养时间的延长而升高，并且氨基酸、糖类以及聚合物类是黑土微生物代谢的最主要碳源；玉米土壤微生物的Shannon-Wiener指数（3.18）、McIntosh指数（5.96）、丰富度指数（24.89）、及Simpson指数（0.95）比其他土地利用方式土壤微生物的多样性指数高，而水稻土壤微生物的多样性指数最低，土豆、大豆与荒地土壤微生物的多样性指数间无显著差别；3）不同土地利用方式显著影响了土壤微生物群落碳源代谢多样性，并且对土壤微生物群落代谢特征起分异作用的主要碳源类型为糖类、氨基酸类和羧酸类，其中糖类尤为突出。该研究将有助于了解黑土区土壤微生物多样性与土地利用方式之间的关系，为黑土区农业的可持续发展提供一定的科学依据。

Soil microbial diversity of black soil under different land use patterns in northeast China

Abstract: Soil microorganisms participate in the energy flow and nutrient cycle of soil ecosystem, affecting the geochemical cycle process of organisms. Their diversity and community compositions play an important role in determining the function and sustainability of soil ecosystem. The functional diversity of soil microbial community is one of the important indexes to express the soil microbial community and ecological function. Soil microbial diversities of black farmland under different land use types are of great significance to the rational utilization and protection of soil resources. This paper explored the diversity of black soil microorganisms under different land use patterns of farmland, including maize, rice, soybean and potato, and taking the wasteland as the control. The Biolog Eco microplate method and pure culture of bacteria were used to study the changes of soil microbial diversity under four different land use patterns in the black soil area of central and southwest Heilongjiang province. The results showed that: 1) The number of culturable bacteria from more to less were potato, rice, soybean, maize, wasteland, but the variation of Shannon-Wiener diversity index from high to low was: wasteland (2.18), maize (2.11), potato (2.00), rice (1.73), soybean (1.49). 2) The utilization degree of carbon source of microorganisms in black soil under different utilization patterns increased with the extension of culture time. We found that amino acids, carbohydrates and polymers were main carbon sources for the metabolism of microorganisms in black soil. The Shannon-wiener index (3.18), McIntosh index (5.96), richness index (24.89) and Simpson index (0.95) of maize soil microorganisms were higher than those of other land use patterns, among which the diversity index of rice soil microorganisms was the smallest. There was no significant difference between the diversity index of potato, soybean and wasteland. Maize was better suited to the soil environment of farmland in the black soil area of Heilongjiang Province. 3) Principal component analysis identified two principal component factors that were related to carbon sources and explained 54.43% and 7.95% of the variance, respectively. Principal component analysis showed that different land use patterns significantly affects the metabolic diversity of carbon sources in the soil microbial community, and the main types of carbon sources that differentiated the metabolic characteristics of the soil microbial community were carbohydrates, amino acids and carboxylic acids, among which carbohydrates were particularly prominent. It showed that different land use patterns can affect the functional diversity of soil microorganisms. The results of this study is helpful to understand the relationship between soil microbial diversity and land use patterns of farmland in black soil area and provides certain scientific basis for agricultural development and scientific and rational utilization of black soil resources.