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秦博
, 黄金风
QIN Bo, HUANG Jinfeng
中图分类号: S153.6
文献标识码: A
文章编号: 1006-7167(2017)05-0017-04
通讯作者:
收稿日期: 2016-09-19
网络出版日期: 2017-05-20
版权声明: 2017 《实验室研究与探索》编辑部 《实验室研究与探索》编辑部 所有
基金资助:
作者简介:
作者简介:秦 博(1992-),男,吉林白山人,硕士生,主要研究方向为土壤与植物营养研究。Tel.:18243085665;E-mail:675914667@qq.com
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摘要
针对延边州东部和龙市和珲春市苹果梨园土壤,分别选取剖面点并进行挖掘,根据土壤物理状态划分土壤自然发生层,分层采集土壤样品,采用31P-NMR核磁共振波谱法对果园不同土层土壤磷化合物变化趋势进行研究。结果显示:和龙、珲春两市苹果梨园土壤磷化合物组成均含有正磷酸盐、正酸磷单酯和焦磷酸盐,且正磷酸盐>正酸磷单酯>焦磷酸盐;与珲春苹果梨园相比,和龙苹果梨园的A层和AB层土壤含有磷酸二酯。随着土层深度增加,正磷酸盐所占磷化和物的比例总体呈升高趋势,两地最深层土壤的正磷酸盐比例均高达80%以上; 与正磷酸盐相反,随着土层深度增加磷酸单酯所占磷化合物的比例呈减小的趋势。两地苹果梨园土壤磷化合物中,焦磷酸盐所占比例最大的土层均为AB层。磷酸单酯在和龙苹果梨园土壤中的丰富度明显高于珲春苹果梨园土壤。
关键词：
Abstract
Aiming at soil in apple-pear orchard of Hunchun city and Helong city in the east of Korean Autonomous Prefecture of Yanbian of Jilin Province, the authors mined soil profile in apple-pear orchard, collected soil samples from different soil genetic horizon according to soil properties. We studied the change trend of phosphorus compound in different horizons of orchard soil by 31P nuclear magnetic resonance spectroscopy (NMR). The results indicated that phosphorus compounds of orchard soil of Hunchun and Helong were composed of orthophosphate, orthophosphate monoester and pyrophosphate (orthophosphate>orthophosphate monoester >pyrophosphate). Compared with apple-pear orchard of Hunchun, the horizons of A and AB contained orthophosphate diester. With increasing of depth of soil horizon, the percentage of orthophosphate of phosphorus compound was increased as well. The percentage of orthophosphate was more than 80% in the deepest soil of the two orchards. In contrast with orthophosphate,by the increase on depth of soil horizon, the percentage of orthophosphate monoester to phosphorus compound reduced. The soil horizon with the most percentage of pyrophosphate was AB horizon in soil of the two apple-pear orchards in Hunchun and Helong. The abundance of orthophosphate monoester in soil of apple-pear orchard of Helong was significantly higher than that in Hunchun.
Keywords：
延边州地处北纬41°59'~44°30'的东北亚金三角地带,不仅有东北地区冷凉的天气特征,又因临近日本海而具有海洋性湿润气候的特点,形成了当地独特的低温且近似海洋性的大陆季风气候,主要表现为季风明显,春季干燥多风,夏季温热多雨,秋季凉爽少雨,冬季寒冷期长。由于独特的气候条件,形成了典型暗棕壤。全州星罗棋布大量苹果梨园,是亚洲最大的苹果梨生产基地。
磷是植果树生长发育必须的大量元素,不仅影响果树的产量也直接影响着果实的品质,对果树来说具有不可替代的作用。对于果树而言,在其进行机体重要生理过程光合作用的碳同化与光和磷酸化过程中,均有磷元素的直接参与,所以缺少磷元素势必会导致果树的光合作用不能进行[1]。土壤磷素缺乏会导致作物减产,而过量的累积又会增加土壤磷素流失的风险[2-3]。磷在土壤中的存在形态和化学行为会直接影响其对果树的有效性而一直受到人们的广泛关注[4-6]。在自然界中磷的形态多种多样,按照其成键类型可分为正磷酸盐、磷酸单酯、磷酸二酯、焦磷酸盐、膦酸盐、多聚磷酸等磷化合物。20世纪80年代,Newman等[7]首次利用31P-NMR技术分析了土壤提取物中不同形态磷化合物的分布情况,自此31P-NMR技术被广泛研究和利用。作为自然界中唯一丰度为100%的磷同位素, 31P是一种可用核磁共振技术分析含磷化合物结构的理想原子核。在实际的研究中,由于存在于不同官能团的原子核会因屏蔽效应不同而出现不同的化学位移值,因此通过分析31P-NMR波谱图上的化学位移值可以鉴别具有不同空间结构的有机或无机磷化合物[8]。相比其他方法而言,31P-NMR检测法具有高速、准确、分辨率高、无干扰等优势[9],其在磷化合物鉴定方面的优势传统化学方法不可比拟,它能从复杂的土壤提取液中清楚地鉴定出不同形态的磷[10]。我国对土壤磷化合物的研究不多,对果园土壤磷化合物的分析研究更是没有涉及,因此,本文以延边州两市苹果梨园土壤为试材,采用核磁共技术鉴定磷化合物,研究果园磷化合物的变化趋势有助于弥补我国果园磷化合物研究的不足,为我国果园尤其是我国北方果园磷循环研究提供理论支持。
供试土壤取自吉林省延边州东部和龙市及珲春市苹果梨园内,土壤类型为暗棕壤。随机选取苹果梨园中长势良好且健康的苹果梨树,避开果园施肥带,在距离树干1 m处设置剖面点,同时在苹果梨园区未种植苹果梨树的荒地或者农田设置为对照剖面点。深挖1 m,根据土壤的颜色、质地、结构、松紧度、干湿度、根系分布等特征,分出土壤的发生层次,依次为A层、AB层、B层、BC层。
土壤样品预处理方法为:称取4 g土样,加入40 mL 0.25 mol/L NaOH和0.05 mol/L Na2EDTA混合液[11],在20 ℃条件下振荡16 h(振荡频率200 r/min),在10 000 r/min冷冻离心机下离心30 min(4 ℃)。上清液按20∶1加入0.11 mol/L NaHCO3+ 0.11 mol/L Na2S2O4液(BD溶液)水平振荡10min后冷冻干燥至粉末状,冷藏待用。
上机前称取土壤浸提液冻干样品300 mg,加入1.5 mL 0.25 mol/L NaOH重新溶解,在冷冻离心机上离心,条件设定为4 ℃, 8 000 g, 5 min,取0.6 mL的上清液转移到5 mm的NMR管中,然后向NMR管中加入0.05 mL D2O,摇匀待测。采用31P-NMR核磁共振波谱法,利用仪器BRUKER AVANCE III HD进行测定。采用 BRUKER 标准腔5 mm 的 BBO 探头,31P谱的脉冲P1=13.90 μs,脉冲功率PL1=40 W,31P的共振频率为202.47 Hz,循环延迟dl=2 s,扫描 20 000次左右,测定温度为 296.2 K 。所有31P化学位移均参照85%的正磷酸。
根据各类磷化合物在31P核磁共振图谱上的位移显示:正磷酸盐化学位移在(6~8)×10-6;磷酸单酯化学位移在(3~6)×10-6;磷酸二酯化学位移(-1~2.5))×10-6;焦磷酸盐化学位移在(-5~-2.5)×10-6[7、12-13];单核苷酸化学位移在(4.78-4.32)×10-6;磷酸胆碱化学位移4.05×10-6;鲨肌醇六磷酸化学位移在4.14×10-6;肌醇六磷酸脂化学位移在(5.85~4.92)×10-6和(4.55~4.43)×1
数据采用SPSS软件和Excel软件进行统计分析。
由图1可见,珲春果园磷化合物由正磷酸盐、酸磷单酯和焦磷酸盐组成。由图2可见,珲春果园土壤中磷化合物比例为正磷酸盐>酸磷单酯>焦磷酸盐。正磷酸盐和磷酸单酯作为磷化合物的主要组成因素,两者之和超过了磷化合物总量的85%。
图2显示,正磷酸盐的相对百分含量随着土壤层次的加深而增加,试验材料中最深层的珲春果园B层土壤,正磷酸盐所占磷化合物比例达到了近90%;与正磷酸盐相反,磷酸单酯所占比重的趋势却是随着土壤层次的加深而减少。核磁图谱中同一类磷化合物的峰的个数与该化合物的丰富度呈正相关。图1中果园31P核磁共振图谱显示,珲春果园A层土壤磷酸单酯类化合物出峰个数为8个,而AB层和B层分别为5个和4个,随着土层加深,磷酸单酯不仅所占百分比降低,其丰富度也下降。对比图1中果园附近的荒地土壤,挖掘与果园土壤同样深度仅出现到AB层。磷酸二酯在果园土壤中未测出,但在珲春荒地土壤的A层土壤中被检测到,占磷化合物总量的2.12%。珲春苹果梨园内,A层土壤中主要磷化合物为有机磷酸单酯,而其他层次则以正磷酸盐为主(见图2)。
从图3可看出,和龙土壤检测出正磷酸盐、酸磷单酯、正磷酸二酯和焦磷酸盐4种磷化合物,且这四类磷化合物在土壤中含量如图4所示,为:正磷酸盐>酸磷单酯>焦磷酸盐>正磷酸二酯(见图4)。
结合图4中的和龙果园和荒地土壤可以看出:果园A至B层土壤正磷酸盐所占比例明显高于荒地相同土层土壤。和龙农田BC层土壤的正磷酸盐所占比例极高,达到97.82%。无论是果园土壤或是农田土壤,磷酸单酯所占磷化合物的比例的总体趋势都是随着土壤层次的加深而减小。果园A至B层磷酸单酯所占比例高于农田的A至B层。图3中果园31P核磁共振图谱显示,和龙果园A层土壤磷酸单酯类化合物出峰个数为14个,AB层为11个,B层和BC层土壤均为7个。可见磷酸单酯的丰富度随着土壤层次的加深而呈现降低趋势。磷酸二酯是这四类磷化合物中唯一没有分布在所有层次中的磷化合物,从图4中看出,磷酸二酯只分布于果园AB及以上土层和农田B层及以上土层中,随着土壤深度增加而减少。作为和龙果园四类磷化合物中含量最少的化合物,即使在所占比例最大的农田土A层也只有3.2%。焦磷酸盐虽然在磷化合物中所占比例相对较少,但是无论果园土壤还是农田土,每个层次均有焦磷酸盐存在。焦磷酸盐所占磷化合物的比例的总体趋势是随着土壤层次的加深先增加后减少。
和龙苹果梨园与珲春苹果梨园的土壤中,均含有正磷酸盐、酸磷单酯和焦磷酸盐3种磷化合物,且3种磷化合物所占比例均为正磷酸盐>酸磷单酯>焦磷酸盐;两地土壤中磷酸单酯的比例都是随着土壤层次的加深而减少,且磷酸单酯的丰富度也在随着土层的加深而降低;两地土壤中焦磷酸盐所占比重最大的层次都是AB层土壤。
和龙苹果梨园土壤中磷化合物的丰富度高于珲春苹果梨园土壤,与珲春苹果梨园土壤相比,和龙苹果梨园土壤含有磷酸二酯,且存在于A和AB两个层次内。磷酸单酯是两地苹果梨园土壤中出峰较多的化合物,但是和龙果园土壤的磷酸单酯出峰个数明显高于珲春苹果梨园土壤,在AB层甚至高出2倍以上。
延边州东部两市和龙市和珲春市的苹果梨园土壤中均含有正磷酸盐、酸磷单酯和焦磷酸盐3种磷化合物,且3种磷化合物所占比例均为正磷酸盐>酸磷单酯>焦磷酸盐;不同的是地处北部的珲春市苹果梨园中未含有磷酸二酯,而南部的和龙市苹果梨园土壤的A层和AB层均含有磷酸二酯。磷酸单酯在和龙苹果梨园土壤中的丰富度明显高于珲春苹果梨园土壤,其中AB层更是高出2倍以上。
总体趋势来看,两地正磷酸盐的比例都是随着土壤层次的加深而升高,但是磷酸单酯的比例及其丰富度却随着土壤层次的加深呈现降低的趋势;两地土壤中焦磷酸盐所占比重最大的层次都是AB层土壤。
果树对磷肥的吸收主要是无极正磷酸盐类,对于珲春果园表层土无机正磷酸盐比例偏低的情况来看,建议其适当追加无机磷肥,或者调整施肥比例。
The authors have declared that no competing interests exist.
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针对延边州珲春市苹果梨园土壤,在苹果梨园内布置剖面点,挖掘剖面,根据土壤形态划分土壤自然发生层,分层采集土壤样品,采用改进Bowman-Cole法测定了土壤中不同土层各种形态的有机磷含量.结果表明:在珲春苹果梨园地区,各剖面层次荒地有机磷总量均高于苹果梨园;随土层深度增加,有机磷各组分含量整体呈下降趋势;有机磷各组分中,活性有机磷表现更易于植物吸收;有机磷各组分占有机磷总量的比例不尽相同,其共同之处表现为中活性有机磷组分在有机磷总量中占有较高的比例,中活性有机磷为珲春苹果梨园土壤中重要的有机磷形态.
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Characterizing phosphorus in environmental and agricultural samples by 31P nuclear magnetic resonance spectroscopy [J].DOI:10.1016/j.talanta.2004.12.024 URL PMID: 18969999 [本文引用: 1] 摘要
Phosphorus nuclear magnetic resonance ( 31P-NMR) spectroscopy has advanced our knowledge of organic phosphorus (P) in soils and environmental samples more than any other technique. This paper reviews the use of 31P-NMR spectroscopy for soil, water and other environmental samples. The requirements for a successful solid-state or solution 31P-NMR experiment are described, including experimental set-up, sample preparation, extractants, experimental conditions, and post-experimental processing. Next, the literature on solid-state and solution 31P-NMR spectroscopy in environmental samples is reviewed, including papers on: methods; P transformations; agricultural, forest and natural ecosystem soil studies; humic acid and particle size separations; manure, compost and sludge studies; and water research, including freshwater, estuary and marine studies. Future research needs are also discussed as well as suggestions to improve results, such as increased standardization among research groups.
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| [9] |
Optimizing phosphorus characterization in animal manures by solution phosphorus-31 nuclear magnetic resonance spectroscopy [J].DOI:10.2134/jeq2004.7570 URL PMID: 15074830 [本文引用: 1] 摘要
Abstract A procedure involving alkaline extraction and solution 31P nuclear magnetic resonance (NMR) spectroscopy was developed and optimized for the characterization of P in animal manures (broiler, swine, beef cattle). Inclusion of ethylenediaminetetraacetic acid (EDTA) in the alkaline extraction solution recovered between 82 and 97% of the total P from the three manures, which represented a significant improvement on recovery in NaOH alone. Low concentrations of paramagnetic ions in all manure extracts meant that relatively long delay times (> 5 s) were required for quantitative analysis by solution 31P NMR spectroscopy. The manures contained inorganic orthophosphate, orthophosphate monoesters, orthophosphate diesters, and inorganic polyphosphates, but results were markedly influenced by the concentration of NaOH in the extractant, which affected both spectral resolution and the apparent P composition of the extracts. For example, extraction of swine manure and broiler litter with 0.5 M NaOH + 50 mM EDTA produced remarkable spectral resolution that allowed accurate quantification of the four signals from phytic acid, the major organic P compound in these manures. In contrast, more dilute NaOH concentrations produced considerable line broadening that obscured individual signals in the orthophosphate monoester region of the spectra. Spectral resolution of cattle manure extracts was relatively unaffected by NaOH concentration. Improvements in spectral resolution of more concentrated NaOH extracts were, however, compromised by the disappearance of phospholipids and inorganic polyphosphates, notably in swine and cattle manure extracts, which indicated either degradation or a change in solubility. The optimum extraction conditions will therefore vary depending on the manure type and the objectives of the study. Phytic acid can be accurately quantified in swine manure and broiler litter by extraction with 0.5 M NaOH + 50 mM EDTA, while a more dilute NaOH concentration should be used for complete P characterization or comparison among different manure types.
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| [10] |
Phosphatase activity in temperate pasture soils: Potential regulation of labile organic phosphorus turnover by phosphodiesterase activity [J].DOI:10.1016/j.scitotenv.2005.02.003 URL PMID: 15907508 [本文引用: 1] 摘要
Phosphatase enzymes regulate organic phosphorus (P) turnover in soil, but a clear understanding remains elusive. To investigate this, phosphomonoesterase and phosphodiesterase activities were determined by using para-nitrophenol ( pNP) analogue substrates in a range of temperate pasture soils from England and Wales. Substrate-induced phosphatase activity ranged between 2.62 and 12.19 μmol pNP g 611 soil h 611 for phosphomonoesterase and between 0.25 and 2.24 μmol pNP g 611 soil h 611 for phosphodiesterase. Activities were correlated strongly with soil pH and labile organic P extracted in sodium bicarbonate, although the relationships differed markedly for the two enzymes. Acidic soils contained high phosphomonoesterase activity, low phosphodiesterase activity, and high concentrations of labile organic P, whereas the reverse was true in more neutral soils. As most of the organic P inputs to soil are phosphate diesters, it therefore seems likely that phosphodiesterase activity regulates labile organic P turnover in pasture soils. The low phosphodiesterase activity in acidic soils may be linked to the dominance of fungi or an effect of sorption on the enzyme. These results suggest that greater emphasis should be placed on understanding the role of phosphodiesterase activity in the cycling of soil organic P.
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| [11] |
Solution phosphorus-31 nuclear magnetic resonance spectroscopy of soils from 2005 to 2013: A review of sample preparation and experimental parameters [J].DOI:10.2136/sssaj2013.05.0187dgs URL [本文引用: 1] 摘要
ABSTRACT Phosphorus nuclear magnetic resonance (P-31 NMR) spectroscopy is an important tool for the study of soil P and has significantly advanced our knowledge of soil P forms, particularly organic P; however, it must be used correctly to provide meaningful results. This review covers the P-31 NMR studies of soil published from 2005 to 2013. The first part discusses preparing samples for P-31 NMR, including extractants, pre- and post-extraction treatments, the physical state of the soil sample at the time of extraction, extraction length, the soil/extractant ratio, P recovery, P in residues, methods to concentrate extracts, redissolving samples for P-31 NMR experiments, the use of the internal standard methylene diphosphonic acid, and the potential for degradation with any of these steps. The second part of this review focuses on NMR experiment parameters, including delay times, proton decoupling, and experiment length. Potential concerns in these areas are noted, and suggestions are given for procedures to optimize the information obtained from a P-31 NMR experiment.
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| [12] |
A 31P nuclear magnetic resonance study of the phosphorus species in alkali extracts of soils from long-term field experiments [J].DOI:10.1111/j.1365-2389.1984.tb00257.x URL [本文引用: 1] 摘要
The different forms of phosphorus (P) in 0.5 m sodium hydroxide extracts of soils from long-term field experiments at Rothamsted were characterized by 31 P-nuclear magnetic resonance spectroscopy (NMR). The extract from an old grassland soil (pH 4.6) from a plot of the Park Grass Continuous Hay Experiment that had received no fertilizer or lime for at least 125 years contained the following forms of P: inorganic orthophosphate (22% of the extracted P), orthophosphate monoesters (49%), orthophosphate diesters (14%), phosphonates (3%), pyrophosphate (4%) and two unidentified forms of P (7%). The soil extract from a Park Grass plot given inorganic phosphate fertilizer (35 kg P ha 1 ) annually for 121 years contained the same forms of P and, in addition, a small amount of polyphosphate. There was also evidence of an increase in the orthophosphate monoester fraction. Another old grassland soil, of pH 6.1, contained more total and organic P than Park Grass but the extract contained fewer forms of P: inorganic orthophosphate (14% of the extracted P), orthophosphate monoesters (39%), orthophosphate diesters (34%) and an unidentified form (13%). An area of this grassland that had been ploughed up 20 years previously, and kept bare since, contained less organic P. The extract contained less of the phosphate diesters but the more stable monoesters remained relatively unchanged.
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| [13] |
A comparison of soil extraction procedures for 31P NMR spectroscopy [J]. |
| [14] |
Phosphorus-31 nuclear magnetic resonance spectral assignments of phosphorus compounds in soil NaOH-EDTA extracts [J].DOI:10.2136/sssaj2003.0497 URL 摘要
Soil P composition can be conveniently determined in alkaline extracts using solution 0601P nuclear magnetic resonance (NMR) spectroscopy, but spectral assignments are based on fragmentary literature reports of model compounds in various extraction matrices. We report solution 0601P NMR chemical shifts of model P compounds, including inorganic phosphates, orthophosphate monoesters and diesters, phosphonates, and organic polyphosphates, determined in a standardized soil P extractant (0.25 M NaOH and 0.05 M EDTA). Signals from nucleic acids (DNA -0.37 ppm, RNA 0.54 ppm) and phospholipids (phosphatidyl choline 0.78 ppm, phosphatidyl serine 1.57 ppm, phosphatidyl ethanolamine 1.75 ppm) could be differentiated in the orthophosphate diester region, and were identified in a sample of cultured soil bacteria. Inorganic and organic polyphosphates could be differentiated by the presence of a signal at -9 ppm from the phosphate of organic polyphosphates. Some orthophosphate diesters, notably RNA and phosphatidyl choline, degraded rapidly to orthophosphate monoesters in NaOH–EDTA although DNA, other phospholipids, and orthophosphate monoesters were more stable. Changes in probe temperature had a marked influence on signal intensities and the relative magnitude of signals from orthophosphate monoesters and inorganic orthophosphate, and we suggest that solution 0601P NMR spectroscopy of soil extracts be performed at 20°C.
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| [15] |
Application of 31P and 27Al MAS NMR for phosphate speciation studies in soil and aluminium hydroxides: Promises and constraints [J].
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| [16] |
Identification of scyllo-inositol phosphates in soil by solution phosphorus-31 nuclear magnetic resonance spectroscopy [J].DOI:10.2136/sssaj2004.0802 URL 摘要
ABSTRACT phosphate using hypobromite oxidation, a procedure that destroys all organic matter except inositol phosphates. Lower order scyllo- of soil organic P, can now be accurately quantified in inositol phosphate esters were not identified in the extracts studied complex spectra with the aid of simple deconvolution here, and literature reports suggest that they probably occur in insuffi- software (Turner et al., 2003c). cient concentrations to be detected by this procedure. The identifica- The aim of this study was to develop a procedure for tion of scyllo-inositol hexakisphosphate in soils and other environ- the determination of scyllo-inositol phosphates in soil mental samples will allow its quantification in a range of environments, extracts using alkaline extraction and solution 31P NMR and facilitate research into the origins and function of this enigmatic spectroscopy. To achieve this we measured 31P NMR compound. chemical shifts of synthetic scyllo-inositol phosphate standards in alkaline solution, then used hypobromite oxidation to demonstrate the presence of scyllo-inositol
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