KMS XINJIANG INSTITUTE OF ECOLOGY AND GEOGRAPHY，CAS
| 聚谷氨酸对盐碱土壤中盐蒸发结晶的影响 | |
| 谭文娟 | |
| Subtype | 硕士 |
| Thesis Advisor | 张道勇 |
| 2018-06-01 | |
| Degree Grantor | 中国科学院大学 |
| Place of Conferral | 新疆乌鲁木齐 |
| Degree Discipline | 工程硕士 |
| Keyword | 盐碱土 蒸发结晶 Ca-P γ-PGA Saline-alkaline soil evaporative crystallization Ca-P γ-polyglutamic acid |
| Abstract | 土壤盐碱化是土壤退化的一种表现，新疆的盐碱耕地面积在逐年增大。面对耕地土壤不断的盐碱化，肥料的施用效果以及盐碱土改良问题不断引起大家关注。如何提高盐碱土壤中磷肥的施用效果，开发出一种抑制盐蒸发结晶，保肥的环境友好型产品值得研究。聚谷氨酸是一种微生物合成产物，保水保肥剂，其在盐碱土壤中的应用研究比较少，且对磷肥的影响作用及影响机理有待于研究。本论文选用聚谷氨酸（γ-PGA）来研究其对盐碱土壤中盐蒸发结晶的影响，研究其在盐溶液中对 Ca-P 沉淀的影响，并通过等温滴定量热法（ITC）验证了聚谷氨酸与HPO42-， Ca2+， Na+相互间的络合能力；聚谷氨酸在实际盐碱土壤溶液中对盐蒸发结晶的微观研究；同时从纳豆中筛选了一株产聚谷氨酸的菌株，研究菌株本身对盐碱土壤溶液中盐蒸发结晶的影响；为了进一步验证聚谷氨酸在盐碱土壤中对植物生长的影响，进行了盆栽实验，以说明聚谷氨酸对盐碱土壤中盐分的影响尤其是磷的影响。主要结果如下：（1）在盐溶液蒸发结晶过程中，聚谷氨酸能延缓钙质（HAP 和碳酸钙）磷酸盐的沉淀，其延缓沉淀的机理为 γ-PGA 能为 Ca2+提供高于 Ca2+与 HPO42-之间络合的结合位点数的两个数量级。在实际盐碱土壤溶液蒸发结晶过程中，聚谷氨酸对盐结晶的类型和结晶顺序无明显影响，其中氯化钠、 Ca-P、碳酸钙在结晶过程中一直在析出。在土壤溶液蒸发结晶的初期，Ca-P 沉淀主要变现形式为 Ca2-P，Ca3-P， Ca4-P，这些是磷酸氢钙盐的沉淀盐，是水不溶性的。蒸发结晶结束后，Ca-P 沉淀形式主要为羟基磷灰石。另外，在蒸发结晶过程中，聚谷氨酸能显著降低盐碱土壤溶液中盐离子（Cl-、 Ca2+、 Na+）的含量，且又能抑制氯化盐与硫酸盐的结晶速率，同时能显著增加盐碱土壤溶液中的可溶性总磷含量。（2）枯草芽孢杆菌 Bacillus subtilis DKU NT 03 在盐碱土壤溶液蒸发结晶过程中能显著降低盐碱土壤溶液的 pH。施用菌液能在加 5 mM P 的盐碱土壤溶液的整个阶段显著提高土壤溶液中活性磷酸盐的含量，而对其他盐分包括阴离（Cl-，SO42-）及阳离子（Na+）浓度的显著降低影响及对 Ca2+浓度的显著增加影响只体现在蒸发结晶过程中的某个时间阶段。另外，在盐碱土壤溶液蒸发结晶过程中，该菌液的加入抑制了盐晶体的结晶速率，使得出现的结晶物相类型稳定，在蒸发结晶结束之后，出现的结晶类型相对于空白对照组无差异。（3）在盐碱土壤中种植甜菜施用聚谷氨酸，当甜菜生长到 5~6 片真叶时，施用适量的聚谷氨酸（100 mg/L）显著增加了甜菜的鲜重及干重，并显著降低了土壤中的可溶性盐含量。另外，随着甜菜栽培时间的增加，经 γ-PGA 处理的土壤的 pH 变化不显著，未经 γ-PGA 处理的土壤的 pH 是显著增加的。 甜菜根际土壤蒸发结晶出现的结晶盐类型中，经γ-PGA 处理的土壤盐结晶，相对于空白对照，钙盐（硫酸钙以及碳酸钙）相对比例随着聚谷氨酸浓度的增大是减少的趋势。另外，在甜菜栽培一个月收获后测定甜菜的全磷含量，发现聚谷氨酸处理促进了土壤中磷的利用率，根际土壤中盐结晶的羟基磷酸钙为痕量，根际土壤中损失的有效磷均被植物吸收利用。 |
| Other Abstract | Soil salinization is a manifestation of soil degradation. The area of saline-alkalicultivated land in Xinjiang has increased year by year. The continuous salinizationof arable land, the application of fertilizers and the increment of saline-alkali soilcontinue to arouse everyone's attention. How to improve the application effect ofphosphate fertilizer in saline-alkali soil and develop an environment-friendlyproduct that inhibits salt evaporation, crystalization, and water retention are worthstudying. Polyglutamic acid is a product of microbial synthesis, water-retaining andfertilizer-retaining agent, and its application in saline-alkali soil is less studied. Itsinfluence on phosphate fertilizer and its influencing mechanism need to be studied.In this thesis, polyglutamic acid (γ-PGA) was used to study its effect on saltevaporative crystallization in saline-alkali soil, and its effect on Ca-P precipitation insalt solution was studied, and isothermal titration calorimetry (ITC) was used. Theinteraction between polyglutamic acid and hydrogen phosphate ions, calcium ionsand sodium ions was verified. A microscopic study of salt evaporative crystallizationof polyglutamic acid in saline soil solution; a polyglutamic acid-producing strainwas screened from natto to study the effect of the strain itself on salt evaporationcrystallization in saline soil solution. In order to further verify the effect ofpolyglutamic acid on the growth of plants in saline soil, a pot experiment wasconducted to illustrate the effect of polyglutamic acid in saline-alkali soil, especiallythe impact on phosphate fertilizers.The main results are as follows:(1) In the process of evaporation and crystallization of salt solution,polyglutamic acid can delay the precipitation of calcium (HAP and calciumcarbonate) phosphates, and its mechanism of delaying precipitation is that thenumber of binding sites between complexes γ-PGA can provide Ca2+ more than Ca2+ and HPO42- is two orders of magnitude. In the process of evaporation andcrystallization of saline-alkaline soil solution, polyglutamic acid has no obviouseffect on the type and crystallographic order of salt crystals, among which the NaCl,Ca-P and calcium carbonate are always saturated in the crystallization process. Inthe initial stage of evaporation and crystallization of the soil solution, Ca-Pprecipitates mainly in the form of Ca2-P, Ca3-P, Ca4-P, which is precipitation salts ofcalcium hydrogen phosphate salts and are water-insoluble. After evaporativecrystallization is complete, Ca-P precipitates mainly in the form of hydroxyapatite.In addition, in the process of evaporation and crystallization, polyglutamic acid cansignificantly reduce the content of salt ions (Cl-, Ca2+, Na+) in the saline-alkali soilsolution, and can also inhibit the crystallization rate of chloride salts and sulfates,and at the same time can significantly Increase the soluble total phosphorus contentin saline soil solution.(2) Bacillus subtilis DKU NT 03 can significantly reduce the pH of saline soilsolution during evaporation and crystallization of saline soil solution. Theapplication of the bacteriostatic liquid can significantly increase the content of activephosphate in the soil solution during the entire period of adding 5 mM P saline soilsolution, while it significantly affected the concentration of other salts includinganions (Cl-, SO42-) and cations (Na+). And the effect of a significant increase in Ca2+concentration is only reflected in a certain period during the evaporativecrystallization process. In addition, in the process of evaporation and crystallizationof saline-alkali soil solution, the addition of the bacteria inhibits the crystallizationrate of the salt crystals, so that the type of crystalline phase appearing is stable, andthere is no difference in the type of crystals appearing with respect to the blankcontrol group after evaporation and crystallization finish.(3) When sugar beet was applied to saline soil in the application ofpolyglutamic acid, and when sugar beets were grown to 5 to 6 true leaves, theapplication of an appropriate amount of polyglutamic acid (100 mg/L) significantly increased the fresh weight and dry weight of sugar beets. In the same time, itreduces soluble salt content in the soil. In addition, with the increase of sugar beetcultivation time, the pH of the soil treated with γ-PGA did not change significantly,and the pH of the soil not treated with γ-PGA was significantly increased. Amongthe crystalline salt types that occur during the evaporation and crystallization ofsugar beet rhizosphere soil, the salt crystals of soil treated with γ-PGA are relative tothe blank control. Among the crystalline salt types that occur in the evaporativecrystallization of sugar beet rhizosphere soil, the γ-PGA-treated soil salt crystals,relative to the blank control, with the increase of polyglutamic acid concentration,the relative proportions of calcium salts (calcium sulfate and calcium carbonate), itis a decreasing trend. In addition, the total phosphorus content of sugar beet wasmeasured after one-month harvest of sugar beet, and it was found that polyglutamicacid treatment promoted the utilization of phosphorus in the soil, and the calciumhydroxyphosphate in the salt crystals in the rhizosphere soil was a trace amount, andwas lost in the rhizosphere soil. The available phosphorus is absorbed by plants. |
| Subject Area | 环境工程 |
| Language | 中文 |
| Document Type | 学位论文 |
| Identifier | http://ir.xjlas.org/handle/365004/14987 |
| Collection | 研究系统_荒漠环境研究室 |
| Affiliation | 中国科学院新疆生态与地理研究所 |
| First Author Affilication | 中国科学院新疆生态与地理研究所 |
| Recommended Citation GB/T 7714 | 谭文娟. 聚谷氨酸对盐碱土壤中盐蒸发结晶的影响[D]. 新疆乌鲁木齐. 中国科学院大学,2018. |
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