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1.
土壤重金属元素测定方法比较   总被引:1,自引:0,他引:1  
采用3种方法:M3-双硫腙、DTPA-AAS、EDTA-AAS测定了土壤中有效态锌的含量,并且进行比较,研究了M3-双硫腙方法的精密度、重现性,并分别进行了M3浸提剂及双硫腙萃取剂重现性的重现性实验。结果表明:M3-双硫腙法与标准参比法呈显著相关,M3浸提剂及双硫腙萃取剂的重现性好。M3-双硫腙法精密度高、工效快,可用于土壤重金属的联合速测。  相似文献   

2.
刘婷娜  苏永中  范桂萍  张珂 《土壤》2018,50(5):924-928
使用常规浸提剂与两种联合浸提剂Mehlich 3(M3)、ASI分别测定了中国8个地区10种土壤样品的有效磷、速效钾含量,分析比较了常规浸提剂与两种联合浸提剂测定土壤有效磷速效钾的差异性及相关性。统计分析表明,对于有效磷,M3、ASI两种联合浸提剂的浸提结果均大于常规浸提剂的浸提结果,且M3浸提剂浸提结果的变幅较常规浸提剂浸提结果相对较小,而精确度较高。相关分析表明,常规浸提结果与M3浸提结果呈极显著正相关(P0.01),相关系数为0.680。对于速效钾,M3浸提剂的浸提量较常规浸提剂相近,常规浸提量与M3浸提量呈极显著正相关(P0.01),相关系数为0.996。综合而言,M3这种联合浸提剂是测定土壤有效磷、速效钾的理想浸提方法。  相似文献   

3.
采用AB-DTPA浸提剂和电感耦合等离子体发射光谱法分析测定了上海土壤样品中8种元素的有效态含量,并与CaCl2-DTPA法比较,结果显示:AB-DTPA法分析土壤Cu、Zn、Mg、Ni、S、Cr、Mo和As 8种元素的有效态含量均高于CaCl2-DTPA法;其中AB-DTPA法测定Cu、Zn、Mg、Ni、S、Cr、Mo 7种元素的有效态含量与CaCl2-DTPA法均达到极显著相关;而AB-DTPA,CaCl2-DTPA两方法测定土壤有效态的As几乎不相关。结果表明:AB-DTPA法对这8种元素有效态的浸提率高于CaCl2-DTPA法,而两者的分析结果大多相关性好,由此可见,AB-DTPA法更适用于土壤此8元素有效态含量的分析测定。表8,参16。  相似文献   

4.
几种浸提剂对土壤有效硫测定的相关性探讨   总被引:3,自引:0,他引:3  
崔岩山  王庆仁  董艺婷  李海峰 《土壤》2003,35(2):136-139,144
采用4种浸提剂(CaCl2、Ca(HzPO4)2(pH=4.0)、KH2PO4、NaHC03(pH=8.5)),对来自我国不同区域的7种土壤样品及北京近郊昌平平西府中科院遗传所试验基地冬小麦不同生育期麦田土壤进行了土壤有效S的浸提,同时对不同区域土壤的有效S、全S和小麦不同生育期植株的含S量进行了测定。结果表明,在土壤有效S与植株含S量的相关性中,4种方法都达到显著或极显著的水平。采用电感辊合等离子体原于发射光谱法(ICP—AES)和BaS04比浊法对Ca(H2PO4)2浸提的土壤有效S进行测定,二者的结果具有极显著的相关性,r值达0.867^**。二者测定的土壤有效S与植株含S量的相关性也达到了极显著水平,r值分别为0.794^**和0.684^**,说明了两种方法都适用于对土壤有效S的测定,但ICP—AES法的结果相对更稳定。4种浸提剂测定重复结果间的变异系数以Ca(H2PO4)2平均最小,只有5.3%,NaHC03最高,达8.3%。根据浸提剂的性质、土壤有效S与小麦植株含S量的相关性、测定结果重复间的变异系数得出,Ca(H2PO4)2浸提与离子色谱测定是判定土壤有效S最稳定的一种方法。  相似文献   

5.
不同浸提剂以及保存方法对土壤矿质氮测定的影响   总被引:4,自引:0,他引:4  
为探明影响土壤矿质氮测定的因素,从棕壤、潮土和黄棕壤3种类型土壤中各采集10个经不同施肥处理的土样,用连续流动注射分析仪测定经不同浸提剂以及不同保存方法处理后土样的NO3-N和NH4-N含量。结果表明:不论是棕壤、潮土还是黄棕壤,2 mol.L?1 KCl提取硝态氮的数量与0.01 mol.L?1 CaCl2提取的数量相关性均达到P<0.01水平;3种土壤各个土样硝态氮含量的测定值多表现为新鲜土<冷冻土<风干土;将鲜样浸提后作短时间的冷冻处理,其效果与鲜样24 h内的测定结果较接近;土样不同保存方式以及浸提液的保存时间对3种土壤NH4-N测定结果的影响规律不及NO3-N明显。  相似文献   

6.
山西石灰性土壤速效磷、钾测定方法的比较   总被引:9,自引:0,他引:9  
马骏  郭丽娜  刘秀珍 《土壤通报》2006,37(3):620-621
用M ehlich3通用浸提剂法对山西石灰性土壤速效磷、钾的含量进行了测定,并与常规方法进行比较。结果表明:M ehlich3法与常规土壤速效磷、钾测定方法的测定结果呈显著正相关性。磷的替代性较差,钾的替代性较好,且两元素之间可以相互换算。  相似文献   

7.
刘庆  夏江宝  陆兆华 《水土保持学报》2012,26(1):124-127,135
利用EDTA、DTPA、M3和ASI 4种提取剂对黄河三角洲不同利用方式土壤中Fe、Mn、Cu、Zn 4种微量元素有效形态进行提取,探讨不同提取剂对土壤微量元素的提取效果,并以DTPA提取的结果为基础,评价Fe、Mn、Cu、Zn 4种元素在土壤中的丰缺状况。结果表明:EDTA对4种元素的提取能力最强,M3提取能力相对较弱,但各提取剂对不同利用方式土壤微量元素的提取能力并不一致;DTPA所提取的微量元素有效态含量与总量相关性最好,其相关性程度均达到显著或极显著水平,明显优于其他3种提取剂;土壤中有效态含量较为丰富的元素是Cu,其含量范围为0.62~2.31mg/kg,除未利用地土壤有效Cu为中等水平外,其他3种用地类型中土壤有效Cu均达到丰富和极丰富水平,而土壤有效Mn含量范围为2.2~7.54mg/kg,4种用地类型土壤有效Mn均处于较低和极低的水平。  相似文献   

8.
为准确测定土壤中有效磷的含量,提升工作效率,在Olsen 法的研究基础上,采用碳酸氢钠浸提- 电感耦合等离子体发射光谱仪(ICP-OES)测定土壤中的有效磷含量,使用正交实验法优化土壤有效磷测定条件,确定了浸提液体积40 mL、振荡时间30 min、振荡浸提温度30℃、稀释倍数2 倍(1 mol/L 的盐酸溶液稀释)的最优条件,对该条件及实验方法进行验证。结果表明,该方法有效磷含量在0 ~ 10 mg/L 范围内线性良好,线性系数为0.9999;方法检出限为0.0435 mg/kg,定量下限为0.174 mg/kg;精密度和准确度良好,土壤标准物质的测定结果均在认定值范围内,相对误差为0.5% ~ 6.2%,相对标准偏差(n=12)为1.8% ~ 6.6%。碳酸氢钠浸提- 电感耦合等离子体发射光谱仪(ICP-OES)测定土壤中的有效磷含量,结果准确可靠,操作流程简单,减少试剂用量,可适用于批量土壤有效磷样品测试工作。  相似文献   

9.
采用盆栽实验及石墨炉原子吸收光谱法测定,比较了HOAc、MgCl2、NH4OAc、EDTA和EDTA-NH4OAc等5种浸提剂在不同提取时间、不同土液比下对土壤中有效态钒的提取效果。实验表明,不同浸提剂对土壤有效态钒的提取率明显不同,提取率均随土壤钒含量的升高而升高。浸提剂对土壤有效钒的提取率顺序依次为HOAcMgCl2NH4OAcNH4OAc-EDTAEDTA,其中0.05 mol L-1 EDTA的浸提效率最高,最大提取率61.1%。最佳提取条件为:平衡时间60 min、土液比1∶10。将拟定的提取方法用于玉米盆栽土壤中有效态钒的提取,土壤中有效态钒量与玉米根、茎叶中钒含量存在极显著的相关性,相关系数达0.9742和0.9497,故EDTA提取的有效态钒能很好地用于评价土壤中钒的植物可利用性。  相似文献   

10.
江苏省几种低硒土壤中硒的形态分布及生物有效性   总被引:25,自引:3,他引:22  
利用连续浸提技术研究了江苏省低Se地区 3种土壤 (旱作土和太湖地区水稻土 )的Se含量及其形态分布。结果表明 ,3种土壤Se含量均偏低 ,尤其是长江沉积物发育的砂土属于贫Se土壤。对土壤Se形态分析表明有机物 硫化物结合及元素态Se是这些土壤中Se的主要存在形态 ,其次是残渣态 ,二者之和约占土壤总Se含量的 70 %~ 80 %。 5种形态中 ,除盐酸可提态Se趋向于向犁底层富集外 ,其他几种形态均为耕作层接近或高于犁底层。可溶态Se含量受其他形态Se影响较小 ,受土壤 pH值的影响较大 ;可交换态Se则相反 ,与除可溶态Se外的其他形态和土壤全Se含量均有显著正相关关系 ,但与土壤 pH值和土壤有机质无关。 5种有效Se浸提剂中 ,0.5mol/LNaHCO3浸提的Se与植株含Se量有极显著正相关关系 ,可作为低Se土壤的有效Se浸提剂  相似文献   

11.
Different relationships between soil-test methods results have been reported in several agricultural regions. Differences in the same soil-test procedure (e.g., soil/solution ratio) exist between soil-testing laboratories from different agricultural regions. Our objectives were to (1) determine the effect of soil/solution ratio on the amount of phosphorus removed by Bray 1 and Mehlich 3 methods, (2) compare the amounts of phosphorus removed by Bray 1 and Mehlich 3 in Mollisols from the Pampean region, and (3) determine whether soil/solution ratio affects the relationship between Bray 1 and Mehlich 3. Soil phosphorus availability was determined with two extractants (Bray 1 and Mehlich 3), using two soil/solution ratios (1:10 and 1:8, wt/v) in 72 soils (noncalcareous, loess-derived Molisolls) from the Pampean region. The amount of phosphorus removed was 20–24% greater when using 1:10 than 1:8 (wt/v) soil/solution ratio. This effect was significantly greater in Bray 1 than in Mehlich 3 (p = 0.04). When compared using the same soil/solution ratio, Mehlich 3 removed 4 to 8% more phosphorus than Bray 1. The soil/solution ratio used in the comparison affected the relationship between both extractants. The difference between extractants was slightly greater with a soil/solution ratio of 1:8 than of 1:10 (p = 0.03). Our results showed that even when using the same method, changes in the procedure (like soil/solution ratio) may cause different soil-test results and also differences in the relationship between two extracting solutions. Therefore, reported relationships between two methods are only valid for the soils and region where the relationship was developed and should not be extrapolated to other regions, even with similar soils.  相似文献   

12.
Abstract

The extractant Mehlich‐1 is routinely used in Brazil for determination of soil nutrients, whereas Mehlich‐3 has been suggested as a promising extractor for soil fertility evaluation. Both were used for extraction of molybdenum (Mo) in Brazilian soils with Mo dosage by the KI+H2O2 method. The Langmuir and Freundlich isotherms were used to study soil Mo adsorption. Mehlich‐1 extracted more Mo than Mehlich‐3 in soils with high contents of organic matter, clay, and iron (Fe) oxides. Mehlich‐3 and Mehlich‐1 extractions correlated positively and significantly with amorphous Fe oxides, crystalline Fe oxides, and organic matter. Molybdenum recovering rates correlated to crystalline Fe oxides and clay contents but not to organic matter, pH, and Mo adsorption capacity. Amorphous and crystalline Fe oxides, clay, and organic matter were responsible for most of the Mo adsorption. The Langmuir isotherm described better the Mo adsorption to soil amorphous Fe oxides and organic matter than the Freundlich isotherm.  相似文献   

13.
为探究贵州省名优茶产地不同深层土壤对茶叶矿质元素溯源效果的影响,以土壤-茶叶的多矿质元素法结合主成分分析(PCA)、反向传播(BP)神经网络法、逐步线性判别分析(SLDA)对茶叶产地进行溯源。结果显示,不同产地的茶叶和土壤具有独特的矿质元素指纹,茶叶中Fe、Mn、K、Ca、Mg、Cu的含量与土壤中对应元素含量显著相关(P<0.05),以这6种矿质元素含量结合PCA可有效区分茶叶的地理起源;不同深层土壤对茶叶产地的溯源有不同影响,通过SLDA法、BP神经网络法明确了以60~80 cm的土层进行产地溯源的效果最优,产地溯源验证判别率分别为98.5%(SLDA法)和100%(BP神经网络法),并基于SLDA法确定了Zn、Cu、P、Mn、Fe、Mg和K 7种元素构建的贵州名优茶产地溯源模型。此外,研究发现茶叶产地溯源几乎不受茶树品种的影响。本研究结果为贵州省名优茶矿质元素指纹图谱的建设及土壤-茶叶产地溯源的关系研究提供了理论依据。  相似文献   

14.
In this study, four soil extraction methods (Olsen, Soltanpour, Mehlich 3, and water saturation) were used to identify optimal concentrations of phosphorus (P) required for plant growth. Olsen soil extraction for P was the most appropriate method for soil types of this study as the greatest correlation coefficient for soil-test P and with plant factors was achieved. The optimal amount of soil features (pH, organic carbon, lime, gypsum, and clay) determined by using response surface methodology (a new optimization method) were 7.49, 0.66, 41.82, 4.21, and 31.34, respectively. More soil P was extracted when the soil had optimal amounts of these features, showing each feature had a significant effect on extracted soil P. Furthermore, the graphical method of Cate–Nelson determined the optimal amounts of P using Olsen, Soltanpour, Mehlich 3, and saturation extract methods for wheat as 15, 6.5, 35, and 1.5 mg kg?1 soil in nongypsic soils and 17, 3.5, 45, and 2.5 mg kg?1 soil in gypsic soils.  相似文献   

15.
Soil testing is widely adopted as an essential diagnostic tool for identifying soil nutrient factors that limit sustained crop production. A systematic approach for rapid soil testing and fertilizer recommendation has been introduced and widely used in China by Agro Services International (ASI), USA. To verify the usefulness and reliability of the ASI method in soil testing and fertilizer recommendation in comparison with other commonly used traditional soil testing methods, 294 soil samples from major agricultural regions and soil types in China with a wide range of soil pH, from 5.1 to 8.9, were taken and analyzed for available phosphorus (P) and potassium (K) by the ASI multielement extraction solution and selected traditional methods, Olsen extractant for P, ammonium acetate (NH4OAc) extractant for K, and multielement extractant Mehlich 3 for P and K. Also, 46 soils were selected from northern China regions for a greenhouse trial with sorghum seedlings to determine if the soil testing values correlate well with plant response. Results indicated that the amount of soil P extracted by the ASI method (ASI P) was correlated to both soil extractable P tested by the Olsen extractant (Olsen P) and Mehlich 3 extractant (Mehlich 3 P). The correlation coefficient of ASI P with Mehlich 3 P (R2 = 0.86) was greater than that of ASI P with Olsen P (R2 = 0.74) across all selected soils. A good correlation was also found between the exchangeable K from the ASI method with the traditional ammonium acetate method (R2 = 0.81) and the Mehlich 3 method (R2 = 0.85). The results from the greenhouse trial showed that the extractable P and exchangeable K by the ASI multielement extraction solution could be used to represent the fertility status of soil P and K for the selected soils. Regression analysis indicated that the relative dry-matter yield of the sorghum plants can be predicted with either ASI P and ASI K values with the correlation coefficients (R2) values of 0.78 and 0.72 respectively and could be a good measure for soil testing and fertilizer recommendation in the selected soils and regions in China.  相似文献   

16.
The soil microbial biomass (SME) content and fluorescein diacetate (FDA) hydrolytic activity in 21 acidic tea field soils in Japan were determined. SM 3 content in the tea field soils was quantitatively similar to that in 13 arable soils with neutral soil pH previously reported. However, the ratio of the SMB content to organic matter content in the tea field soils classified as red-yellow soil, brown forest soil, and lithosol was clearly lower than that in the neutral arable soils classified as non-volcanic ash soil. FDA hydrolytic activity in the tea field soils was higher than the activity in various soils with neutral soil pH and showed a negative relationship with the soil pH.  相似文献   

17.
南京典型利用方式土壤中球囊霉素含量及剖面分布特征   总被引:2,自引:0,他引:2  
阙弘  葛阳洋  康福星  凌婉婷 《土壤》2015,47(4):719-724
采用Brad-ford染色法研究了南京市5种典型利用方式土壤不同土层中(0~10、10~20、20~40 cm)球囊霉素的含量。结果表明:土壤中总球囊霉素含量为1.96~3.12 mg/g,占土壤有机碳的12.5%~29.0%,所占比例随土壤有机碳含量的增加而降低。林地和草地土壤中球囊霉素和有机碳的含量均高于3种耕作土壤(水稻田、茶园土和菜园土)。随着土层深度(0~40 cm)的增加,5种不同利用方式土壤中总球囊霉素和有机碳的含量均减小;与其他土层相比,0~10 cm土层总球囊霉素和有机碳含量均最大。耕作土壤中易提取球囊霉素更易于向总球囊霉素转化。发现5种土地利用方式下土壤中总球囊霉素含量与土壤有机碳含量极显著正相关,与土壤p H显著负相关;易提取球囊霉素与土壤有机碳含量极显著负相关。总球囊霉素和易提取球囊霉素可作为评价土壤丛枝菌根真菌活性和土壤质量的重要指标。  相似文献   

18.
Abstract

The effect of grinding on soil extraction was determined for two soil fractions and three extractants. Arsenic (As), beryllium (Be), cadmium (Cd), cobalt (Co), chromium (Cr), copper (Cu), nickel (Ni), lead (Pb), vanadium (V), and zinc (Zn) were extracted by aqua regia and 2 M nitric acid. Mehlich 3 extractant was used for determination of potassium (K), magnesium (Mg), calcium (Ca), phosphorus (P), iron (Fe), and aluminum (Al). One hundred forty‐seven agricultural soil samples representing all major soil types, climatic regions, and proportions of agronomic cultures in the Czech Republic were collected for the study. Particle size fractions smaller than 2 mm and smaller than 0.150 mm were chosen for investigation. Extraction of elements by aqua regia was similar for both size fractions of soil. Cold 2 M nitric acid is a weaker extractant than aqua regia, and a statistically significant increase in extractable Be (5%), Cd (6%), Co (11%), Cu (5%), Ni (5%), and V (2%) was measured with the finely ground soils. An increase for the finer fraction for K (10%) and Mn (25%) was found for Mehlich 3. A more complex nonlinear relationship was found for Mehlich 3 extractable Al and Fe. This was probably caused by a more intensive re‐adsorption of Fe and Al to the finely ground soils.  相似文献   

19.
Soil phosphorus (P) tests for flooded rice (Oryza sativa L.) generally present uncertainties for estimating P availability. Bray 1, 1% citric acid, Mehlich 3, Olsen extractants (dry samples), and Bray 1 extractant after 3 days (BI3) and 7 days (BI7) of anaerobic incubations were evaluated to estimate P availability for rice in 43 Uruguayan soils. Field trials were conduced at each site (0, 13, 26, and 39 kg P applied ha?1). Relative yield and absolute and relative yield increases were determined. Extracted P was variable for the different tests. For silty soils, P availability was better estimated by citric acid, Mehlich 3, and Bray 1, with similar soil P critical concentrations (6?8 mg P kg?1). The BI3 and BI7 tests showed greater soil P critical concentration but poorer correlations with yield indexes. This study contributes to the scientific basis of P fertilization for flooded rice, promoting more effective fertilizer use and minimizing environmental P losses.  相似文献   

20.
Abstract

Various soil tests are used to estimate phosphorus (P) availability for both crop uptake and potential loss to water. Conversion equations may provide a basis for comparison between different tests and regions, although the extent to which information can be interchanged is uncertain. The objective was to determine and quantify relationships between specific soil test extractants for samples taken annually in October and February over 4 years from four sites in each of eight soil series under grassland. The extractants comprised Mehlich‐3, Morgan, Olsen, Bray‐1, lactate–acetate, CaCl2 (1∶2 and 1∶10 soil–solution ratios), and resin. The results showed distinct relationships for each soil series, for which individual lines regression models (different intercepts and slopes) were superior to a single conversion equation across all soils. The ensuing difference between soils was large and ranged from 1.9 to 8.0 and 9.2 to 15.6 mg kg?1 P for Morgan and Olsen, respectively, at 20 mg kg?1 Mehlich‐3 P. Generally, the environmentally oriented tests CaCl2 and resin correlated best with Morgan. Some soil‐specific limitations were also observed. CaCl2 was less efficient than Morgan, and Morgan less efficient than Mehlich‐3 on a high Fe–P soil derived from Ordovician‐shale diamicton, compared with the general trend for other soils. This finding suggests that further disparity may arise where evaluation of critical, or other, limits across regions involves even a limited sequence of tests.  相似文献   

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