长期施肥对土壤团聚体组成及其主要养分赋存特征的影响

发布时间：2018-04-19 07:53

本文选题：长期施肥 + 棕壤　；参考：《沈阳农业大学》2015年硕士论文

【摘要】：土壤团聚体是土壤结构的物质基础和肥力的重要载体,其组成与稳定性受生物与非生物因素的共同影响。长期施用有机肥和化肥均能够在不同程度上影响土壤团聚体的组成,同时使土壤生物的生境发生改变,进而对土壤养分的分布和有效性产生影响。本研究依托沈阳农业大学棕壤长期定位试验站(26年),并选取对照、单施氮肥、单施有机肥和有机肥配施氮肥四个施肥处理,采用干筛法分离出四种不同粒径大小(2 mm,1～ 2 mm,0.25-1 mm和0.25mm)的团聚体,分析了各团聚体中的主要养分状况,包括土壤有机碳、主要全量养分、速效养分以及土壤pH值和阳离子交换量,旨在研究长期不同施肥处理对不同粒级土壤团聚体组成的影响,明确不同施肥条件下有机碳及氮、磷、钾元素在团聚体中的分布特征,探讨了团聚体数量与土壤养分储量和团聚体稳定性之间的关系。研究结果表明：(1)不同施肥处理条件下土壤团聚体均以0.25～1 mm为优势粒级。与对照相比,有机肥施用与有机无机配施增加了大团聚体(0.25mm)含量,提高了团聚体的平均重量直径(MWD)和几何平均直径(GMD)值,增强了土壤的团聚程度,有利于土壤的结构稳定性形成；而无机肥处理则增加了微团聚体(0.25mm)含量,降低了土壤团聚化程度,使土壤结构稳定性下降。(2)有机肥处理和有机无机配施处理增加了各粒级团聚体的有机碳(SOC)、全氮(TN)、全磷(TP)和全钾(TK)含量,但各粒级养分含量增加的程度并不一致,其中大团聚体(0.25mm)中增加较多；各处理下大团聚体较微团聚体中有更高的有机碳、全氮、全磷和全钾储量。(3)有机肥单施和有机无机配施处理下土壤各粒级的碱解氮(AN)、有效磷(AP)和速效钾(AK)含量较对照和无机肥处理均有所提高。AN含量随团聚体粒径增加而降低；AP含量随团聚体粒径变化不显著,AK随团聚体粒径增加而增加。另外,有机肥和有机无机配施均可提高各粒级阳离子交换量(CEC),而无机肥处理则降低了各粒级土壤CEC,但相同处理不同粒级间CEC差异不显著(P0.05)。(4)土壤总有机碳、全氮和全磷储量均与2 mm团聚体含量呈显著正相关(P0.05)。2 mm.1～2 mm团聚体含量和平均重量直径(MWD)、几何平均直径(GMD)呈显著正相关(P0.05),其中2mm团聚体含量与MWD、GMD达到极显著正相关(P0.01)。因此,在农业生产过程中可以施用有机肥来改善土壤结构、提高土壤肥力。
[Abstract]:Soil aggregate is the material basis of soil structure and the important carrier of fertility. Its composition and stability are affected by both biological and abiotic factors.Long-term application of organic fertilizer and chemical fertilizer can affect the composition of soil aggregates in varying degrees and change the habitat of soil organisms thus affecting the distribution and availability of soil nutrients.This study relied on the long-term location test station of brown soil of Shenyang Agricultural University (26 years), and selected four treatments: single application of nitrogen fertilizer, single application of organic fertilizer and organic fertilizer combined with nitrogen fertilizer.Four kinds of aggregates with different diameters (2 mm ~ 2 mm ~ 0.25 mm and 0.25 mm) were separated by dry sieve method. The main nutrient status of each aggregate was analyzed, including soil organic carbon, main total nutrients, available nutrients, soil pH value and cation exchange capacity.The purpose of this study was to study the effects of long-term fertilization on the composition of soil aggregates at different grain levels, and to determine the distribution characteristics of organic carbon, nitrogen, phosphorus and potassium elements in the aggregates under different fertilization conditions.The relationship between aggregate quantity and soil nutrient storage and aggregate stability was discussed.The results showed that the dominant grain size of soil aggregates was 0.251mm under different fertilization treatments.Compared with the control, the application of organic fertilizer and organic inorganic fertilizer increased the content of large aggregates (0.25mm), increased the mean weight diameters (MWD) and geometric mean diameters (GMDs) of aggregates, and enhanced the degree of soil agglomeration.The inorganic fertilizer treatment increased the content of micro-aggregate 0.25mm and reduced the degree of soil agglomeration.The soil structure stability was decreased by organic fertilizer treatment and combined application of organic and inorganic fertilizer. The contents of organic carbon (SOC), total nitrogen (TNN), total phosphorus (TK) and total potassium (TK) were increased by organic fertilizer treatment and organic and inorganic fertilizer treatment, but the increase of nutrient content was not consistent with each grain level.There was a higher organic carbon, total nitrogen, total nitrogen in the large aggregate than in the microaggregate under each treatment, the content of organic carbon was higher than that of the microaggregate, and the content of total nitrogen was higher than that of the microaggregate.Total phosphorus and total potassium reserves. 3) the contents of alkali-hydrolyzed nitrogen ANN, available phosphorus and available K _ (k) in each grain of soil under organic fertilizer alone and organic-inorganic fertilizer treatments were higher than those of the control and inorganic fertilizer treatments. An content increased with the increase of aggregate size.The decrease of AP content with the change of aggregate particle size was not significant. AK increased with the increase of aggregate particle size.In addition, organic fertilizer and organic-inorganic combination could increase cationic exchange capacity (CEC) of each grain, but inorganic fertilizer treatment could decrease CEC in each grain-grade soil, but there was no significant difference in CEC between different grains in the same treatment (P0.05N. P0.05N. 4) soil total organic carbon (TOC).The total nitrogen and total phosphorus reserves were positively correlated with the content of 2 mm aggregates (P0.05 ~ (2)) and the mean weight diameter (mm.1~2), and the geometric mean diameters (GMD) showed a significant positive correlation (P _ (0.05)), among which the content of 2mm aggregates was significantly positively correlated with the content of 2mm aggregates (P _ (0.01)).Therefore, organic fertilizer can be applied to improve soil structure and soil fertility in agricultural production.
【学位授予单位】：沈阳农业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S158

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