耕作白浆土的固碳性能研究

发布时间：2018-09-05 12:12

【摘要】：研究白浆土的固碳性能及潜力,对于揭示白浆土固碳的机理,丰富白浆土的培肥改良理论具有重要意义,也可为白浆土环境友好型培肥措施的制定提供理论依据。本研究以吉林省东部地区不同有机质含量的耕作白浆土为供试土壤,通过室内模拟培养试验、吸附试验,重点研究了白浆土耕层与成土母质对秸秆转化的碳及腐殖质碳的吸附固定性能,添加玉米秸秆对白浆土耕层和母质层土壤团聚体组成及有机碳分布的影响。取得的研究成果概要如下。一、供试白浆土耕层的颗粒组成中粘粒含量变化在28.25%-38.37%之间,土壤质地为壤粘土;pH范围在4.56-4.82之间,酸性较强;阳离子交换量变化在15.38-17.46 cmol/kg之间。与之相比,母质层土壤粘粒含量为45.13%,土壤质地主要粘土;pH为6.44;阳离子交换量为18.88cmol/kg;供试土壤的粘粒矿物组成主要以蒙脱石及伊利石等2:1型及少量1:1型高岭石等粘粒矿物为主。土壤粘粒的选择性溶解分析中晶质的成分相当高。团聚体组成以2-0.25 mm和0.25mm为优势粒级。上述物质组成及理化特性为白浆土的有机碳固定奠定了丰富物质基础。二、耕层及母质层土壤添加玉米秸秆后,土壤总有机碳、重组有机碳含量及重组有机碳增量均随秸秆添加量的增加而提高。与耕层相比,母质层重组有机碳增量及增率均大于耕层土壤。随着原土有机碳含量的增加,重组有机碳增率、重组占全土比率及粘粒有机复合度(DC)等呈逐渐降低趋势。三、土壤中添加玉米秸秆后,团聚体的组成发生了明显变化。随秸秆添加量的增加,供试土壤2~1 mm粒径团聚体含量呈逐渐增加的趋势,1~0.25 mm呈先增加再减少的趋势,0.25~0.106 mm,0.106 mm粒级的团聚体含量整体趋势为逐渐减少。在耕层土壤中,当秸秆添加量为5%时,2 mm粒级团聚体含量最高。母质层土壤中,当秸秆添加量为10%时,2 mm粒级团聚体含量最高。四、添加玉米秸秆可显著提高土壤团聚体中有机碳含量。当秸秆添加量为10%时,2 mm粒级团聚体的有机碳含量最高。母质和高有机碳耕层土壤在秸秆添加量为10%时2-1mm粒级团聚体的有机碳含量最高,低、中有机碳土壤则在随秸秆添加量的增加2-1mm粒级团聚体的有机碳含量逐渐升高。所有土壤的1~0.25 mm、0.25~0.106 mm、0.106 mm粒级团聚体的有机碳含量均有随秸秆添加量的增加而升高的趋势。五、腐殖酸的吸附试验表明,母质和低有机碳土壤在60min时吸附达到平衡,中、高有机碳土壤在120min时吸附达到平衡,用Elovich方程拟合的r2值较高,拟合效果最好。等温吸附实验中,Langmuir方程、Freundlich方程、Temkin方程均可较好的拟合白浆土对腐殖酸的吸附等温线。母质和耕层土壤用Langmuir拟合最大吸附量分别为65.188 mg/g、56.557mg/g、63.386mg/g、55.188mg/g。同一土壤不同处理的条件下,对腐殖酸的吸附能力表现为:粘粒去有机质土壤原土粉粒。
[Abstract]:The study of carbon sequestration properties and potential of white clay is of great significance for revealing the mechanism of carbon sequestration and enriching the theory of fertilizer improvement, and can also provide a theoretical basis for the formulation of environment-friendly fertilizer cultivation measures. In this study, the cultivated white soil with different organic matter content in eastern Jilin Province was used as the test soil, and the adsorption experiment was carried out through the indoor simulated culture experiment. The adsorption and fixation of straw transformed carbon and humus carbon in cultivated layer and parent material of white soil were studied emphatically. The effects of corn straw on soil aggregate composition and organic carbon distribution in tilling layer and parent layer were also studied. The results of the research are summarized below. The main results are as follows: 1. The clay content in the cultivated layer of the tested alpine soil varies between 28.25% and 38.37%, the soil texture is between 4.56 and 4.82, the pH range is 4.56-4.82, and the cation exchange capacity varies from 15.38 to 17.46 cmol/kg. In contrast, the clay content of the parent layer is 45.13, the soil texture is mainly clay pH 6.44; the cation exchange capacity is 18.88 cmol / kg; the clay mineral composition of the tested soil is mainly composed of 2:1 type montmorillonite and Illite and a small amount of 1:1 kaolinite. The composition of crystal is quite high in the selective dissolution analysis of soil clay. The composition of agglomerates was dominated by 2-0.25 mm and 0.25mm. The composition and physicochemical properties of the above materials lay a rich material foundation for the organic carbon fixation of aluminous soils. Secondly, the content of total organic carbon, the content of recombined organic carbon and the increment of recombinant organic carbon in the topsoil and parent layer increased with the increase of the amount of straw. Compared with tilling layer, the increment and increase rate of recombination organic carbon in parent layer were higher than that in tilling layer. With the increase of soil organic carbon content, the increase rate of recombination organic carbon, the ratio of recombination to the whole soil and the clay organic compound degree (DC) decreased gradually. Thirdly, the composition of the aggregate changed obviously after adding corn straw to the soil. With the increase of the amount of straw, the aggregate content of 2N 1 mm increased gradually, and the content of 0.25 mm increased first and then decreased. The aggregate content of 0.25 mm,0.106 mm 0.106 mm,0.106 mm decreased gradually. In the topsoil, the content of grain aggregates of 2 mm was the highest when the amount of straw was 5. In the parent layer soil, the content of grain aggregates of 2 mm was the highest when the amount of straw was 10%. The content of organic carbon in soil aggregates was significantly increased by adding corn straw. When the amount of straw was 10, the content of organic carbon was the highest. The organic carbon content of 2-1mm aggregates was the highest and the lowest in parent and high organic carbon topsoil, while the organic carbon content of 2-1mm aggregates gradually increased with the increase of straw addition. The content of organic carbon in 1 / 0. 25 mm,0.25~0.106 mm,0.106 mm aggregate of all soils tended to increase with the increase of straw content. 5. Humic acid adsorption experiments showed that the adsorption of parent material and low organic carbon soil reached equilibrium at the time of 60min, while the adsorption of high organic carbon soil reached equilibrium at the time of 120min, and the value of R2 fitted by Elovich equation was higher, and the fitting effect was the best. In the isothermal adsorption experiment, the Langmuir equation and Freundlich equation and Temkin equation can all fit the adsorption isotherm of humic acid in aluminous soil. The maximum adsorption capacity of parent and tilling soils fitted by Langmuir was 65.188 mg/g,56.557mg/g,63.386mg/g,55.188mg/g., respectively. Under different treatments of the same soil, the adsorption ability of humic acid was as follows: clay removal of organic soil silt.
【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】：S154.1

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