长期施肥对黑土肥力及细菌和古菌群落的影响

发布时间：2018-09-18 20:34

【摘要】：东北黑土带是世界著名的三大块黑土带之一,土壤有机质含量高、养分含量丰富、自然肥力高,是我国重要的商品粮基地,对我国的粮食供应和安全起着举足轻重的作用。在我国农业生产中,施肥是提高农田生产力和作物产量的一项重要生产方式,长期施肥导致土壤侵蚀严重、黑土层变薄、有机质含量下降,黑土质量日益退化。目前关于长期施肥对黑土质量的影响已有较多的研究,但采用技术手段相对落后,且往往忽略了土壤微生物区系与土壤理化性质的耦合关系。本研究依托黑龙江已达34年的长期定位试验,通过研究东北黑土长期不同施肥条件下土壤微生物群落结构特征和组成差异,并与土壤化学性质进行关联分析,探讨引起影响土壤微生物区系变化的主效环境因子。试验选取不施肥(CK)、施氮磷肥(NP)、施氮钾肥(NK)、施磷钾肥(PK)、施氮磷钾肥(NPK)共5个施肥模式的耕层土样为研究对象,借助传统化学分析方法和Illumina Miseq高通量测序技术,解析土壤理化性状和细菌与古菌群落结构特征,对微生物群落结构与环境因子进行相关性分析。结果表明:(1)在土壤理化性质方面,与不施肥处理相比,长期施氮肥,土壤全氮、硝态氮、碱解氮、有机质含量显著升高,而pH显著降低;长期施磷肥的NP、PK、NPK处理土壤有效磷含量与不施肥处理相比分别提高了6.6、6.6、8.5倍;长期施钾肥的NK、PK、NPK处理土壤速效钾含量与不施肥处理相比分别提高了30.9%、29.8%、50.6%,表明长期施肥能显著提高相应元素的速效养分含量。(2)在土壤酶活性方面,与不施肥处理相比,土壤过氧化氢酶活性均显著降低;NK处理土壤脲酶和蔗糖酶活性分别提高了30.5%和27.4%,而NP、PK、NPK处理土壤脲酶和蔗糖酶活性无明显变化,表明长期施肥降低了土壤抵御过氧化氢毒害的能力,而不同施肥方式对土壤脲酶和蔗糖酶活性的影响不同。(3)在作物产量方面,NP、NK、PK、NPK四个施肥处理作物产量与不施肥处理相比均显著提高,分别提高了116.5%、59.3%、48.7%、154.1%,并且相互之间存在显著性差异,其中NPK处理作物产量最高,并显著高于其他四个处理。表明施肥提高了土壤提供植物养料和生产生物物质的能力。(4)在土壤微生物数量方面,NP、NK、PK、NPK四个施肥处理土壤细菌和古菌数量与不施肥处理相比均显著提高,分别提高了32.2%、64.5%、165.2%、88.3%,并且相互之间存在显著性差异,其中,PK处理微生物数量最高,并显著高于其他施肥处理。表明施肥提高了土壤细菌和古菌数量,丰富了微生物区系。(5)在微生物群落结构方面,变形菌门是5个不同施肥处理土壤中的优势细菌,而泉古菌门为优势古菌。α多样性分析表明,氮磷钾均衡施肥的NPK处理,土壤细菌的丰富度、多样性及古菌的多样性最高。RDA分析和Pearson相关性分析表明,土壤理化性质和土壤细菌和古菌群落之间存在密切的相关关系,所有的环境因子解释了土壤微生物100%的变化,而土壤pH是影响土壤细菌和古菌群落结构的主效环境因子,贡献了土壤细菌和古菌66.5%(P=0.034)。综上所述,长期施肥显著改变了土壤理化性质、酶活性、作物产量、土壤细菌和古菌的数量和群落结构,长期氮磷钾均衡施肥可以提高土壤速效和长效养分含量、土壤作物产量以及土壤细菌的丰富度、多样性及古菌的多样性,是5种施肥处理中最合理的一种。施氮肥引起的土壤酸碱度的降低是影响土壤细菌和古菌群落结构的主效环境因子。研究结果对指导东北黑土区合理施肥具有重要的现实意义和理论价值。
[Abstract]:Northeast Black Soil Belt is one of the three famous black soil belts in the world. It is an important commodity grain base in China with high content of soil organic matter, nutrients and natural fertility. It plays an important role in grain supply and security in China. Fertilization is an important factor to improve farmland productivity and crop yield in China's agricultural production. Long-term fertilization has resulted in serious soil erosion, thinning of black soil layer, decreasing of organic matter content and deterioration of black soil quality. At present, there are many studies on the effect of long-term fertilization on black soil quality, but the technical means are relatively backward, and the coupling relationship between soil microbial flora and soil physical and chemical properties is often neglected. Based on a 34-year long-term experiment in Heilongjiang Province, the structure and composition of soil microbial community under different long-term fertilization conditions in the black soil of Northeast China were studied and correlated with soil chemical properties. (NP), nitrogen and potassium fertilizer (NK), phosphorus and potassium fertilizer (PK) and nitrogen, phosphorus and potassium fertilizer (NPK) were used to analyze the soil physical and chemical properties and the structural characteristics of bacterial and archaeal bacterial communities. The correlation between microbial community structure and environmental factors was analyzed by traditional chemical analysis and Illumina Miseq high-throughput sequencing technique. The results showed that: (1) in terms of soil physical and chemical properties, long-term application of nitrogen fertilizer, soil total nitrogen, nitrate nitrogen, alkali-hydrolyzed nitrogen, organic matter content increased significantly, but pH decreased significantly; long-term application of NP, PK, NPK soil available phosphorus content increased by 6.6, 6.6, 8.5 times compared with non-fertilization treatment; long-term application of potassium fertilizer, NK, PK, NP The content of soil available K increased by 30.9%, 29.8% and 50.6% respectively under K treatment compared with non-fertilization treatment, indicating that long-term fertilization could significantly increase the content of available nutrients of corresponding elements. (2) In soil enzyme activity, soil catalase activity decreased significantly compared with non-fertilization treatment, urease and sucrase activity increased respectively under NK treatment. 30.5% and 27.4% respectively, while the activities of urease and sucrase in NP, PK and NPK treatments did not change significantly, indicating that long-term fertilization reduced the ability of soil to resist hydrogen peroxide toxicity, and the effects of different fertilization methods on urease and sucrase activities were different. (3) In crop yield, NP, NK, PK and NPK treatments had no significant effect on crop yield. Compared with the other four treatments, the yield of NPK treatment was the highest, which was significantly higher than that of the other four treatments. (4) In terms of soil microbial quantity, NP, NK, PK and NPK were increased. The number of soil bacteria and archaea in the four fertilization treatments increased by 32.2%, 64.5%, 165.2% and 88.3% respectively, and there were significant differences among them. Among them, the number of microorganisms in the PK treatment was the highest and was significantly higher than that in other fertilization treatments. Bioflora. (5) Proteus was the dominant bacteria in five different fertilization treatments, while Archaea was the dominant archaea. Alpha diversity analysis showed that NPK balanced fertilization had the highest richness, diversity and archaea diversity. RDA and Pearson correlation analysis tables The results showed that there was a close correlation between soil physical and chemical properties and soil bacterial and archaeal communities. All environmental factors explained 100% of soil microbial changes. Soil pH was the main environmental factor affecting soil bacterial and archaeal community structure, contributing 66.5% (P = 0.034) to soil bacterial and archaeal communities. Changing soil physical and chemical properties, enzyme activity, crop yield, soil bacteria and archaea quantity and community structure, long-term balanced fertilization of nitrogen, phosphorus and potassium can increase soil available and long-term nutrient content, soil crop yield, soil bacterial richness, diversity and archaea diversity, which is the most reasonable one of the five fertilization treatments. The decrease of soil acidity and alkalinity is the main environmental factor affecting the community structure of soil bacteria and archaea.
【学位授予单位】：山东农业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S158;S154.36

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