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1.
刘兆礼  王敬华 《土壤》1976,8(Z1):324-328
土壤交换量的测定,在常规分析方法中,大都采用醋酸铵法、氯化铵-醋酸铵法、查氏法。上述方法在淋洗土壤吸附性阳离子时,化费的时间较长,手续多,特别是测定石灰性土壤,还须去碳酸钙和脱钙的手续。  相似文献   

2.
以长白山红松人工林为研究对象,运用对比分析方法,对不同林龄红松人工林土壤阳离子交换量空间分布及其组成进行研究。结果表明:红松人工林土壤阳离子交换量和盐基饱和度均随着林龄增加而减小;土壤交换性,氢和交换性铝离子含量则相反,随林龄增大而增加;土壤阳离子交换量、交换性钙、镁离子含量表层大于底层,土壤阳离子交换量及其组成根际土壤大于非根际土壤;土壤阳离子交换量、交换性钙、交换性镁、交换性钠红松阔叶混交林大于红松人工林。  相似文献   

3.
陈定一  胡荣梅 《土壤》1961,4(8):44-47
1.应用亚甲基蓝法测定土壤的阳离子交换量,可广泛适用于酸性土或石灰性土壤;且操作简便。2.测定了12种土壤,样品重复间误差在0.1%左右,其结果与Захарчук法及氟化铵法比较,结果接近。3.处理时间需间歇振荡48小时,使交换作用完全进行。4.土液比依有机质含量及阳离子交换量范围而定,有机质含量 > 1.5%,阳离子交换量在12毫当量/100克土以上者,以0.5:50为宜,以下者以1:50为宜。  相似文献   

4.
采用氯仿熏蒸浸提-紫外分光光度法和消化法比较测定了田间定位试验不同施肥处理土壤、添加植物残体土壤、添加葡萄糖土壤的微生物生物量碳、氮(SMBC,SMBN)。结果表明,当土壤微生物生物量氮含量较高时(>20 mg kg-1),采用分光光度法与消化法测定的SMBN具有显著正相关关系(P<0.05),但当SMBN量较低时(<20 mg kg-1)时,分光光度法测定与消化法测定的SMBN没有显著相关性。当土壤中添加麦秸和玉米秸时,土壤浸提液颜色较深(黄色),不适合采用分光光度法测定SMBN。因此,熏蒸提取–分光光度法测定SMBN,仅适于土壤浸提液无色透明、且SMBN含量较高的土壤。  相似文献   

5.
基于比色化学传感器的特性,通过溶液颜色视觉变化的定性和紫外-可见分光光度法(UV-Vis spectro-photometry)的定量用于可视化检测土壤中可交换态Cu2+的含量。将2~50 mmol/L的Cu(NO3)2溶液掺入到蒙脱土和高岭土中,并且从铜矿区内采集了受污染的土壤样品。基于氯化钙阳离子交换法提取可交换的Cu2+,使用化学传感器通过UV-Vis分光光度法测定溶液中的Cu2+浓度,并与传统的电感耦合等离子体质谱(Inductively Coupled Plasma Mass Spectrometry,ICP-MS)法进行比较分析。结果表明,在受污染的土壤中最低检出浓度为0.030 mmol/L,溶液颜色变化肉眼可辨,能够达到可视化。首次提出了对于比色化学传感器应用于土壤体系中基于CaCl2提取的可交换态Cu2+的定量分析方法,能够对土壤中有害重金属元素的可视化定量检测提供一定的理论基础。  相似文献   

6.
用硝酸提取方法测定石灰性土壤缓效钾含量过程中,在浸提溶液中加入一滴植物油作为消泡剂,可防止浸提液沸腾时溢出管口;用硬质大试管取代三角瓶,并用油浴取代电热板,每次浸提样品数量增加到60个左右,工作效率提高3~4倍.结果表明,浸提方法改进后,同一批样品浸提液开始沸腾时间前后相差5 s左右,浸提液温度基本稳定在103.8℃,平行样检测结果的变异系数在1.2%~2.4%之间,重复样检测结果的变异系数在1.2%~3.3%之间.用改进方法测定不同含量的石灰性土壤缓效钾时,与常规方法有85%的符合率.改进方法测定值与参比土样定值平均值的相对误差在0.4%~3.8%之间.  相似文献   

7.
为了解多年种植烤烟的山地土壤酸度特征,研究了湘西自治州的土壤酸度指标特征及其关系以及植烟年限和土壤类型、有机质、黏粒对土壤酸度的影响。结果表明:(1)植烟年限对土壤酸度的影响大于土壤类型;随植烟年限增加,土壤pH下降,潜性酸度增加,黄棕壤土的交换性盐基、阳离子交换量和盐基饱和度下降。(2)土壤pH与交换性酸为幂函数关系,交换性铝是土壤交换性酸的主体,土壤交换性酸强度随交换性铝及其相对比例的增加而增加。(3)土壤pH与交换性盐基、阳离子交换量、盐基饱和度为二次曲线关系,当pH6时,随土壤pH增加,交换性盐基和阳离子交换量下降,盐基饱和度增加;当pH6时,随土壤pH增加,交换性盐基和阳离子交换量增加,盐基饱和度变幅小。(4)土壤交换性盐基离子主要是交换性钙,其次是交换性镁;对土壤pH影响较大的盐基离子是交换性钙。(5)有机质和黏粒主要影响土壤pH、阳离子交换量、交换性盐基和交换性钙。  相似文献   

8.
鉴定了测定土壤和粘土矿物阳离子交换量(CEC)的4种方法:(1)常规NH4-Na交换法;(2)亚甲基蓝与亚甲基蓝酸容量法;(3)焦磷酸钠法:(4)亚甲基蓝滤纸点测滴定法。供试样品为采自台湾农田的18份表层(0-15cm)土样,并以粘放物学分的4份样品为参照。试验结果表明,在亚甲基蓝溶液的絮凝,平衡时间和浓度都合适的条件下,能用亚甲基蓝吸附法测定土壤和粘土矿物的阳离子代换量。与常规NH4-Na交换法  相似文献   

9.
快速检测土壤阳离子交换量的研究   总被引:2,自引:0,他引:2       下载免费PDF全文
针对土壤阳离子交换量检测行业标准推荐方法耗时长、操作繁琐,介绍了一种定氮仪配合漩涡振荡仪测定土壤阳离子交换量的快速蒸馏法,改进了离心处理环节和蒸馏步骤,讨论了关键流程和注意事项。该方法与行业标准乙酸铵法相比,试剂消耗明显减少,检测效率提高45%,检测精度和准确度符合标准要求,特别适于大批量及快速检出的土壤样品分析。  相似文献   

10.
  【目的】  长期过量施用化学氮肥加剧了红壤区农田土壤酸化,严重制约着该区域农业的可持续发展。施用石灰和有机肥是防治红壤酸化的主要措施,我们研究了有机无机肥配合提高红壤抗酸化能力的作用与机理。  【方法】  本研究基于2009年在湖南祁阳中国农业科学院红壤站开展的有机肥替代化学氮肥长期定位试验,其中4个处理分别为单施化肥(由于酸化严重,于2018年底添加石灰改良)、有机肥替代化肥氮20%、40%和60%,供试有机肥为猪粪。采集2018和2020年的土壤样品,分析各施肥处理红壤pH、交换性酸铝、阳离子交换量、有机质、酸缓冲能力等指标的变化及相互关系。  【结果】  至2018年,单施化肥处理较试验之初土壤pH降低了0.48个单位,交换性酸、铝分别增加了2.74和1.06 cmol/kg;添加石灰改良后,土壤pH升高了0.58个单位,交换性酸、铝分别降低了2.62和1.45 cmol/kg。有机肥替代化肥氮40%和60%处理均可有效防治红壤酸化,其中以替代60%处理效果最佳;至2020年60%有机替代处理土壤pH较初始值提高了0.78个单位,交换性酸和交换性铝分别降低了1.10和1.25 cmol/kg。有机肥替代化肥氮40%和60%处理较单施化肥处理显著提高了土壤阳离子交换量,而石灰改良前后土壤阳离子交换量无显著变化。土壤酸缓冲曲线表明,土壤交换性铝含量随着pH的降低而显著升高,单施化肥、有机肥替代化肥氮20%、40%和60%处理的斜率分别为2.71、2.42、1.93和0.16;土壤交换性铝对pH响应斜率与土壤pH、交换性镁、阳离子交换量、交换性钾、有机质含量呈极显著或显著负相关关系。  【结论】  有机肥替代40%以上化学氮肥既能防治红壤酸化,又能提升红壤抗酸化能力。土壤阳离子交换量和有机质可能是导致土壤交换性铝对pH响应差异的主要因素,即阳离子交换量和有机质含量高的土壤pH降低1个单位时,交换性铝增幅较小,但其作用机理还有待进一步研究。  相似文献   

11.
Three widely used methods for cation exchange capacity determination, viz. sodium acetate, Bascomb's and 45Ca isotopic dilution methods have been compared. Sodium acetate and Bascomb's methods gave similar values for most of the samples. Though some correction for the organic matter and calcium carbonate content are of concern for the 45Ca method, the results do not preclude use of the latter for the cation exchange capacity determination.In the 45Ca method organic matter contributed mostly to the cation exchange capacity, whereas for the other two methods the relative contribution of clay was found to be higher. The lowest contribution of calcium carbonate to the cation exchange capacity was observed in Bascomb's method. Simple and multiple regression relationships between cation exchange capacity and organic matter, clay and calcium carbonate are discussed.  相似文献   

12.
The reactions of two organic (citrate and fulvate) and two inorganic (chloride and phosphogypsum) calcium compounds were studied during leaching of columns of unsaturated acidic soil. The potential of these compounds to decrease the aluminium concentration in the soil solution and remove exchangeable aluminium, and their effects on soil acidity are described. The calcium citrate solution increased the soil solution pH from 5 to a maximum value of 7 in the upper portion of the column. In contrast, the fulvate, calcium chloride and phosphogypsum solutions had little effect on soil-solution pH. Treatment with calcium citrate, or fulvate solution that contained 51 mm Na, removed most of the exchangeable aluminium from the column. The cation exchange sites in the upper portion of the column were saturated with calcium, and the cation exchange capacity of the soil was increased from 35 to c. 80 mmolc kg?1 in the calcium citrate treatment. Leachate from this treatment contained low (< 2 mm ) calcium concentrations and high aluminium concentrations. In contrast, the above changes were not shown by the calcium chloride and phosphogypsum treatments. In these treatments the calcium concentration in the leachate was equal to that in the inflowing solution, which indicated that calcium was transported through the entire column. These results suggest that calcium alone was ineffective in displacing aluminium from the cation exchange sites and a strong complexing agent such as citrate or fulvate is needed to mobilize the exchangeable aluminium.  相似文献   

13.
Zinc (Zn) is a vital plant nutrient that is widely deficient in Thai cultivated calcareous soils. The chemical fractionation and adsorption of Zn are among the most important solid- and liquid-phase interactions that determine the retention of Zn in the soils. This study aimed to investigate the fractionation and adsorption isotherms of Zn in cultivated Thai calcareous soils. The results of sequential extractions showed that Zn is mainly distributed in residual fractions followed by organic-bound, iron and manganese oxides-bound, carbonate-bound, and exchangeable Zn, respectively. Zinc adsorption was well fitted by the Langmuir and Freundlich isotherms. Thai calcareous soils had high Zn adsorption capacity. Soil pH, organic carbon, calcium carbonate, cation exchange capacity, and extractable calcium were the major soil properties that affected the Zn adsorption isotherms in these soils. Zinc hydroxide was the solid precipitate and the Zn hydroxide ion (ZnOH+) was the dominant Zn ion in alkaline equilibrium solution.  相似文献   

14.
免耕与常规耕作潮棕壤交换性阳离子的剖面分布特征   总被引:1,自引:1,他引:0  
通过田间定位试验.研究了不同耕作方式对潮棕壤0-100 cm深度6个土层土壤交换性阳离子的影响.结果表明,与常规耕作相比,免耕使土壤表层pH显著增,.而电导率下降;同时,免耕增加了表层土壤可交换性K~+含量,降低了可交换性Na~+含量,但对可交换性Ca~(2+),Mg~(2+)和阳离子交换量没有产生显著影响.相关分析结果表明,可交换性K~+与土壤养分含量没有显著相关性,而可交换性Na~+,Ca~(2+),Mg~(2+)和阳离子交换量与有机质和全氮含量均呈负相关关系.  相似文献   

15.
The anion exchangeable membrane phosphorus (P) method can be used across a range of soils to analyze P for vegetation and has the potential to be applied to heterogeneous mine soils. Enhanced small-scale variability in mine soils can potentially cause enhanced and irregular P fluctuations during extraction, leading to errors in analysis of exchangeable membrane P. Anion exchange membranes in combination with low ionic solutions may be able to reduce this error and improve precision of the measurement. The authors undertake a full inorganic P fractionation to determine if the ionic solutions [deoionized water (DI), 0.01 M calcium chloride (CaCl2), potassium chloride (KCl), and ammonium fluoride (NH4F)] change the anion exchangeable membrane–extractable P and in turn the fractionation of P. In addition, the relationship between anion exchangeable membrane P and P-buffering index is analyzed to ascertain the accuracy of the methods. The precision and effect on subsequent P fractions for each extracting reagent was specific to the soil type, most likely related to cations in the soil. Use of NH4F and DI with anion exchange membranes was a precise method [coefficient of variation (CV) < 20%] for measuring water exchangeable P, with no or minor changes to subsequent fractionations. Calcium chloride (CaCl2) causes significant changes to P fractionations and resulted in highly variable (CV > 100%) results across all soils.  相似文献   

16.
The physical and chemical properties of Arctic tundra soils were studied along a 250-km latitudinal transect in northern Alaska. The transect includes the nonacidic tundra of the Arctic Coastal Plain, the moist nonacidic tundra of the northern Arctic Foothills, and moist acidic tundra of the southern Arctic Foothills. The parent material of the coastal plain consists of carbonate-rich alluvium. The northern foothills have a mantle of calcareous loess. Further south the parent materials are moraines of late Quaternary. Vegetation changes from sedges on the coastal plain, to grasses on the northern foothills, and tussock and shrub tundra in southern foothills. Following the same order, soil pH and base saturation decrease and soil acidity increases. Most of the soil exchangeable acidity and cation exchange capacity are from soil organic matter.  相似文献   

17.
The soil preference with respect to soil acidity of Asplenium scolopendrium L., Dryopteris filix‐mas (L.) Schott, Pteridium aquilinum (L.) Kuhn as well as of subspecies of the Asplenium trichomanes L. and Polypodium vulgare L. complexes were studied in relation to root cation‐exchange properties. Data were collected for substrate acidity, soil exchangeable cations, and root cation‐exchange capacity. Acidiphilous pteridophytes were characterized by low cation‐exchange capacities. It is unlikely that cation‐exchange properties protect plants from potentially harmful cations such as aluminium or hydrogen, which are abundant under acid soil conditions, through immobilization. It is postulated that cation‐exchange properties are a secondary adaptation to soil acidity, in addition to major adaptations which determine the apparent soil preference. Possibly, a limited variation in cation‐exchange capacity as a function of soil conditions could prevent harmful interactions of soil exchangeable cations with the cation‐exchange sites, such as displacement of cell wall calcium by aluminium or hydrogen ions in acid soils.  相似文献   

18.
不同改良剂对酸性土壤的修复效应   总被引:3,自引:1,他引:2  
为明确不同改良剂对酸性植烟土壤的修复效应,采用盆栽试验,分析了施用丰收延酸性土壤改良剂、金叶酸性土壤改良剂及石灰后土壤pH、水解性酸、潜性酸及土壤交换性能的动态变化。结果表明:施用改良剂可提高土壤pH 3.01%~24.11%,降低土壤水解性酸16.08%~50.46%、交换性Al 3+51.80%~64.27%、交换性H+含量84.12%~93.56%,提高土壤交换性盐基总量45.18%~46.16%、阳离子交换量0.33%~20.10%、盐基饱和度21.35%~49.78%。施用土壤改良剂后,土壤pH先升高后下降,至移栽60天后趋于稳定;土壤水解性酸在烤烟移栽后30~90天差异较小,至移栽后120天略有增加。施用石灰的土壤交换性氢、交换性铝一直下降,但施用丰收延、金叶酸性土壤改良剂的土壤交换性铝下降至烟苗移栽后120天略有增加,土壤交换性氢上升至烟苗移栽后120天大幅度下降。施用土壤改良剂后,土壤交换性盐基总量、阳离子交换量、盐基饱和度一直提高,但变化幅度较小。不同土壤改良剂的材料来源及组成成分不同,其对酸性土壤的恢复效果也不同,以施用石灰的效果最好。  相似文献   

19.
磁力搅拌法改进土壤阳离子交换量测定的研究   总被引:2,自引:0,他引:2  
针对传统土壤阳离子交换量测定方法中的玻璃棒搅拌所存在的分析效率低的问题,开展了运用磁力搅拌替代玻璃棒搅拌的探索性研究。通过平行性实验、条件实验、实验室间对比和不同黏粒含量土壤的CEC测定结果检验,分析了磁力搅拌法的精准度、可操作性、稳定性和适用性。结果表明,磁力搅拌法测定土壤CEC的准确度、精密度均不低于甚至高于玻璃棒搅拌方法,土壤CEC测定值与土壤标准物质认定值吻合。当搅拌时间在1 min、搅拌速度850 r·min–1以上时,延长搅拌时间和提高搅拌速度对分析结果无影响。不同实验室间测定结果相关性好、没有显著性差异。相比传统的玻璃搅拌法,磁力搅拌法具有操作简单、高效,测定结果稳定性好、精准度高等优点,非常适用于大批量土壤CEC的测定。  相似文献   

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