施肥对黑土团聚体多级结构组成及其有机碳分布的影响

发布时间：2018-05-20 14:27

本文选题：土壤团聚体 + 施肥　；参考：《吉林农业大学》2017年硕士论文

【摘要】：土壤中有机碳贮量一直被人们视为衡量土壤肥力的重要标准,一方面是由于其可以为农作物生长发育提供肥力;另一方面是影响大气中温室气体的含量。增强土壤有机碳的固持与稳定的目的是降低土壤CO2释放量与在土壤原基础上提升土壤肥力,促进土壤中团聚结构比例的增加是实现这一目标常用的重要手段之一。东北黑土是我国农业综合生产能力最大的土壤,在自然条件下土质肥沃,其原有机碳含量较高且土壤团聚体结构良好。但随着人口的日益增多与农田的过度开垦与耕作使得土壤物理及化学性状相比之前发生显著变化,探讨不同施肥措施对黑土团聚体组成与有机碳分布影响,对揭示土壤团聚体对土壤有机碳的物理和化学保护机制、土壤固碳机理有着重要科学意义。本文基于长期定位施肥试验,采用水稳性团聚体物理分组方法,把土壤水稳性团聚体分组为0.25 mm大团聚体(Mac-A)、0.25~0.053 mm游离微团聚体(Fm)和0.053 mm粒级的未团聚粉/粘粒(NA-silt/NA-clay),对具有多级结构组成的大团聚体分级得到粗颗粒有机质(cPOM)、闭蓄态微团聚体(mM)、粉/粘粒(M-silt/M-clay),同时结合有机质密度分组,对大团聚体中mM和Fm继续分散得到轻组细颗粒有机质、重组微团聚体内颗粒有机质和微团聚体内粉/粘粒。研究了与不施肥对照处理(CK)相比黑土单施化肥(NPK)、化肥配施生物质炭(NPK+生物质炭)、化肥配施牛粪处理(NPK+牛粪)和化肥配施粉碎秸秆(NPK+秸秆)后对黑土团聚体多级结构组成及其有机碳(SOC)分布的影响,探究生物质炭、牛粪和秸秆施入土壤后多级团聚体结构对SOC的物理和化学保护机制。主要研究结果如下:1.黑土水稳性团聚体组成中,0.25 mm Mac-A占土壤质量比例最高(53.36%~63.07%),为优势粒级,各级团聚体质量比例随着团聚体粒径减小而减少。与CK相比,NPK、NPK+生物质炭、NPK+牛粪和NPK+秸秆处理显著提高了土壤0.25 mm大团聚体质量比例,大小依次为NPK+生物质炭、NPK+牛粪、NPK+秸秆NPKCK;0.25~0.053 mm游离微团聚体均较CK显著减少,表明游离微团聚体在有机胶结物质作用下胶结形成大团聚体。2.与CK相比,NPK+生物质炭、NPK+牛粪、NPK+秸秆处理显著提高了SOC含量(分别提高23.64%、9.50%和8.14%),大小依次为NPK+生物质炭NPK+牛粪、NPK+秸秆NPK、CK。施用生物质炭更有利于SOC的积累。NPK+生物质炭、NPK+牛粪、NPK+秸秆处理显著增加0.25 mm大团聚体中SOC贮量,大小依次为NPK+生物质炭NPK+牛粪NPK+秸秆NPK、CK,对全土SOC的贡献率达到62.52~68.34%。3.对于0.25 mm Mac-A而言,mM占土壤质量比例最高(27.54~36.95%),M-silt次之(17.97~28.55%),M-clay与cPOM占土壤质量比例最低(4.63~6.81%,3.37~6.51%)。与CK处理相比,NPK+生物质炭、NPK+牛粪和NPK+秸秆处理显著提高mM和cPOM的质量比例(分别提高23.97~34.17%和34.72~93.18%),增加mM、M-silt和cPOM的SOC贮量(分别增加1.33~1.41、1.18~1.20和1.78~1.82倍),化肥配施有机物料促进了mM的形成及其SOC贮量的提高。4.对于mM组成而言,NPK+生物质炭、NPK+牛粪和NPK+秸秆处理中闭蓄态微团聚体中的粉粒(mM-silt)、粘粒(mM-clay)、颗粒有机质(mM-POM)以及轻组细颗粒有机质(L-M(f)POM)的质量比例均显著增加。与其它处理相比,NPK+生物质炭处理显著提高了L-M(f)POM、mM-POM和mM-silt的SOC贮量。对于Fm组成而言,与CK相比,NPK+生物质炭、NPK+牛粪、NPK+秸秆处理增加了Fm中轻组细颗粒有机质(L-F(f)POM)的SOC贮量,而Fm中粉粒+粘粒(Fm-silt+clay)的SOC贮量较CK减少;NPK+生物质炭、NPK+牛粪处理中游离微团聚体内颗粒有机质(Fm-POM)的SOC贮量比CK提高。5.与CK或NPK处理相比较,NPK+生物质炭、NPK+牛粪和NPK+秸秆处理显著提高土壤胡敏酸的SOC含量,大小依次为NPK+生物质炭、NPK+秸秆NPK+牛粪CK、NPK,而且,与其它处理相比,NPK+生物质炭处理有利于胡敏酸、富里酸和胡敏素的形成。综上,NPK化肥配施生物质炭、牛粪和秸秆处理提高了黑土SOC含量,促进了0.25 mm大团聚体的形成,提高了大团聚体SOC及其粗POC贮量,SOC主要贮存在大团聚体中,土壤大团聚体对于生物质炭、牛粪和秸秆等外源有机碳在土壤中的固定具有重要作用。NPK化肥配施生物质炭、牛粪和秸秆有利于大团聚体中闭蓄态微团聚体的形成以及闭蓄态微团聚体SOC与POC贮量的提高,从而加强了生物质炭、牛粪和秸秆等外源有机碳在土壤中的稳定性。因此,在大团聚体、微团聚体对生物质炭、牛粪和秸秆等外源有机碳的物理保护作用下,SOC稳定性提高,黑土固C潜力增加。与NPK化肥配施牛粪和秸秆处理相比,NPK化肥配施生物质炭更有利于提高SOC含量,有利于土壤腐殖物质胡敏酸、富里酸和胡敏素的形成,黑土添加生物质炭对于提高和固定SOC、提升土壤质量具有重要意义。
[Abstract]:Soil organic carbon storage has been regarded as an important criterion for measuring soil fertility. On the one hand, it can provide fertility for the growth and development of crops. On the other hand, it affects the content of greenhouse gases in the atmosphere. The purpose of strengthening the fixation and stability of soil organic carbon is to reduce the CO2 release of soil and to extract the soil on the basis of the soil. The increase of soil fertility and the increase in the proportion of reunion structure in the soil is one of the most important means to achieve this goal. The northeast black soil is the largest soil in the comprehensive agricultural production capacity of our country. The soil is fertile under natural conditions, its original organic carbon content is high and the soil aggregates are well constructed. Excessive reclamation and tillage have made significant changes in soil physical and chemical properties, and the influence of different fertilization measures on the composition and distribution of organic carbon in black soil, which is of great scientific significance to reveal the physical and chemical protection mechanism of soil organic carbon and the mechanism of soil carbon fixation. The soil water stable aggregates were grouped into 0.25 mm large aggregates (Mac-A), 0.25~0.053 mm free aggregates (Fm) and 0.053 mm grain grade unreunion powder / clay particles (NA-silt/NA-clay), and the coarse aggregate organic matter (cPOM) and closed storage state of the large aggregates with a multistage structure were obtained by using the water stable aggregate physical grouping method. Microaggregates (mM), powder / clay particles (M-silt/M-clay), combined with organic matter density grouping, continue to disperse the mM and Fm in the large aggregate to get the light group of fine particulate organic matter, and recombine the organic matter in the microaggregates and the powder / clay particles in the microagglomeration. Compared with the non fertilization control treatment (CK), the black soil single application chemical fertilizer (NPK) is compared with the fertilizer, and the fertilizer is applied to the application of biomass. Carbon (NPK+ biomass carbon), chemical fertilizer combined with cow dung treatment (NPK+ cow dung) and chemical fertilizer to smash straw (NPK+ straw) on the multistage structure of black soil aggregates and the distribution of organic carbon (SOC), and explore the physical and chemical protection mechanism of biomass carbon, cow dung and straw into the soil after the application of multistage aggregate structure to SOC. As follows: 1. in the 1. black soil water stable aggregate composition, 0.25 mm Mac-A accounted for the highest soil mass ratio (53.36%~63.07%), which was the dominant grain grade. The mass ratio of aggregates at all levels decreased with the decrease of aggregate particle size. Compared with CK, NPK, NPK+ biomass carbon, NPK+ cow dung and NPK+ straw treatment significantly increased the soil mass ratio of 0.25 mm large aggregate. NPK+ biomass carbon, NPK+ cow dung, NPK+ straw NPKCK, 0.25~0.053 mm free aggregates were significantly lower than CK, indicating that the free micro aggregates formed large aggregate.2. and CK under the action of organic cementation, NPK+ biomass carbon, NPK+ cow dung, NPK+ straw treatment significantly increased the content of.2. (23.64%, 9.50% and 8. respectively. 14%), the size of NPK+ biomass carbon NPK+ cow dung, NPK+ straw NPK, CK. application of biomass carbon is more conducive to the accumulation of SOC carbon, NPK+ cow dung, NPK+ straw treatment significantly increase the SOC storage in the 0.25 mm large aggregates, the size of the NPK+ biomass carbon straw stalk, the contribution rate to the whole soil For 0.25 mm Mac-A, the proportion of mM to soil mass was the highest (27.54~36.95%), M-silt was (17.97~28.55%), and M-clay and cPOM accounted for the lowest soil mass ratio (4.63~6.81%, 3.37~6.51%). 8%) increase the SOC storage of mM, M-silt and cPOM (increase 1.33~1.41,1.18~1.20 and 1.78~1.82 times respectively), chemical fertilizers and organic materials promote the formation of mM and the increase of SOC storage in.4. for mM composition, NPK+ biomass carbon, NPK+ cow dung and straw treated closed storage micro aggregates. The mass ratio of mass (mM-POM) and light group fine particulate organic matter (L-M (f) POM) increased significantly. Compared with other treatments, NPK+ biomass carbon treatment significantly improved L-M (f) POM, mM-POM and mM-silt SOC storage. The SOC storage of F (f) POM and the SOC storage of particles + clay (Fm-silt+clay) in Fm decreased than that of CK; NPK+ biomass charcoal, NPK+ ox dung treatment was compared with the increase of particulate organic matter (Fm-POM) in the free micro aggregates. The size is NPK+ biomass carbon, NPK+ straw NPK+ cow dung CK, NPK, and compared with other treatments, NPK+ biomass carbon treatment is beneficial to the formation of Hu Min acid, fulvic acid and Hu Minsu. To sum up, NPK fertilizer combined with biomass carbon, cow dung and straw treatment improved the black soil SOC content, promoted the formation of 0.25 mm large aggregate, and increased the large agglomeration. Body SOC and its crude POC storage, SOC is mainly stored in large aggregates. Soil aggregates are important for the fixation of exogenous organic carbon in soil, such as biomass carbon, cow dung and straw, and.NPK chemical fertilizer is used for the application of biomass carbon. Cow dung and straw are beneficial to the formation of the closed storage micro aggregates in the large aggregate and the closed aggregate micro aggregate SOC. The increase of POC storage increased the stability of exogenous organic carbon in the soil, such as biomass charcoal, cow dung and straw. Therefore, under the physical protection of organic carbon, such as biomass charcoal, cow dung and straw, the stability of SOC increased and the potential of C in black soil increased. With the application of NPK fertilizer to cow dung and straw treatment NPK fertilizer with biomass carbon is more beneficial to improve the content of SOC, which is beneficial to the formation of soil humic material Hu Min acid, fulvic acid and Hu Minsu, and the addition of biomass charcoal in black soil is of great significance for improving and fixing SOC and improving the quality of soil.
【学位授予单位】：吉林农业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S153.6;S152.4

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