长期施肥对棕壤氨氧化细菌和古菌丰度的影响

发布时间：2018-06-21 22:51

本文选题：棕壤 + 定位试验　；参考：《植物营养与肥料学报》2017年03期

【摘要】：【目的】氨氧化是氮转化过程的限速步骤,其由氨氧化微生物所驱动。本研究旨在探明37年玉米大豆轮作施肥条件下影响棕壤氨氧化微生物丰度的主要影响因子及变化规律。【方法】以沈阳农业大学棕壤肥料长期定位试验耕层土壤(0—20 cm)为材料,选取其中9个施肥处理进行取样分析:不施肥(CK)、低量氮肥(N_1)、高量氮肥(N_2)、氮磷肥(N_1P)、氮磷钾肥(N1PK)、高量有机肥(M_2)、高量有机肥+低量氮肥(M_2N_1)、高量有机肥+氮磷肥(M_2N_1P)、高量有机肥+氮磷钾肥(M_2N_1PK)。采用实时荧光定量PCR技术测定其氨氧化微生物丰度,通过对土壤基本化学性质和氨氧化微生物丰度的冗余分析找出影响氨氧化微生物丰度的主要因素。【结果】施用有机肥处理的土壤p H、有机质、全氮、碱解氮、速效钾、速效磷、铵态氮、硝态氮含量明显高于不施肥和单施化肥处理。各施肥处理土壤有机质、全氮、碱解氮、速效钾、速效磷的含量总体呈现有机肥处理化肥处理CK;与不施肥处理(CK)相比,单施化肥处理显著降低了土壤p H值,施用有机肥处理显著提高了土壤pH值,其中N_2处理的土壤pH最低,M_2处理的土壤pH最高。不同施肥处理氨氧化细菌(AOB)的丰度为0.94×10~6~5.77×10~6 copies/g干土,氨氧化古菌(AOA)的丰度为3.56×10~6~1.22×10~7 copies/g干土;施用有机肥处理AOB和AOA丰度显著高于不施肥和单施化肥处理,其中M2处理的AOB和AOA丰度最高,单施氮肥处理的AOB和AOA丰度最低。冗余分析(RDA)表明,影响棕壤AOB和AOA丰度的主要环境因子有土壤pH、有机质、全氮、碱解氮、速效磷、速效钾,且与AOB和AOA丰度呈正相关关系。【结论】长期轮作施肥显著改变了棕壤的化学性质,从而对氨氧化微生物的丰度产生了显著影响。长期施用有机肥显著提高了土壤养分含量及AOB和AOA的丰度,对维持土壤氨氧化微生物的数量起到十分重要的作用;同时试验结果也为今后通过改变土壤p H、有机质、全氮、碱解氮、速效磷、速效钾等性质对AOB和AOA进行调节提供了依据。
[Abstract]:Aim: ammonia oxidation is a rate-limiting step in nitrogen conversion process, which is driven by ammonia oxidation microorganisms. The purpose of this study was to find out the main influencing factors and their variation laws of the ammoxidation microbial abundance of brown soil under 37 years of maize and soybean rotation fertilization. [methods] the long-term location experiment of brown soil tillage layer in Shenyang Agricultural University was carried out. Soil (0-20 cm) as material, Nine fertilization treatments were selected for sampling and analysis: no fertilization (CK), low nitrogen fertilizer (N1), high nitrogen fertilizer (N2N1P), high organic fertilizer (M2), high organic fertilizer (M2N1), high organic fertilizer (M2N1P), high organic fertilizer (M2N1P). Machine fertilizer nitrogen, phosphorus and potassium fertilizer (M _ S _ 2N _ 1PK). The microbial abundance of ammoxidation was determined by real-time fluorescence quantitative PCR. Based on the redundancy analysis of soil basic chemical properties and ammoxidation microbial abundance, the main factors affecting ammonia-oxidizing microbial abundance were found. [results] soil pH, organic matter, total nitrogen, alkali-hydrolyzed nitrogen and available potassium were treated with organic fertilizer. The contents of available phosphorus, ammonium nitrogen and nitrate nitrogen were significantly higher than those of no fertilization and single fertilizer application. The contents of organic matter, total nitrogen, alkali-hydrolyzed nitrogen, available potassium and rapidly available phosphorus in soil treated with different fertilization treatments showed that CK of organic fertilizer treatment was significantly lower than that of no fertilizer treatment (CK), and the soil pH value was significantly decreased by applying chemical fertilizer alone. The application of organic fertilizer significantly increased the pH value of the soil, and the lowest pH of the soil treated with N-2 and the highest of the soil pH of the treatment of M _ (2) were observed. The abundance of ammonia-oxidizing bacteria (AOB) was 0.94 脳 10 ~ (6) (0.77 脳 10 ~ (6) copies/g dry soil, the abundance of ammonia oxidizing ancient bacteria (AOA) was 3.56 脳 10 ~ (10) ~ (61.22) 脳 10 ~ (7) copies/g dry soil, the abundance of AOB and AOA in organic fertilizer treatment was significantly higher than that in unfertilized and single fertilizer treatments, and the highest in M2 treatment. AOB and AOA abundance were the lowest in single nitrogen fertilizer application. Redundancy analysis (RDA) showed that the main environmental factors affecting AOB and AOA abundance of brown soil were soil pH, organic matter, total nitrogen, alkali-hydrolyzed nitrogen, available phosphorus and available potassium. There was a positive correlation between AOB and AOA abundance. [conclusion] Long-term rotation fertilization significantly changed the chemical properties of brown soil, which had a significant effect on the abundance of ammonia-oxidizing microorganisms. Long-term application of organic fertilizer significantly increased soil nutrient content, AOB and AOA abundance, and played a very important role in maintaining the amount of soil ammonia-oxidizing microorganisms. The properties of alkali-hydrolyzed nitrogen, available phosphorus and available potassium provide basis for the regulation of AOB and AOA.
【作者单位】：沈阳农业大学土地与环境学院;土壤肥料资源高效利用国家工程实验室;金正大生态工程集团股份有限公司;
【基金】：国家自然科学基金(31471940,41501305)资助
【分类号】：S154.3

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