四苯硼钠溶液中含钾矿物非交换态钾的释放特性研究

含钾矿物的全钾含量、非交换态钾总量以及非交换态钾的释放速率因矿物种类而异,且3种参数之间没有必然的相关性。供试5种含钾矿物非交换态钾总量由高到低的顺序是:金云母 5.19% 黑云母3.08% 蛭石2.01% 白云母1.18% 钾长石0.24%,占各矿物全钾的比例分别为:58.4% 、99.7% 、62.5% 、14.2% 和4.98% ,平均达48%。选择较弱提取力的四苯硼钠溶液进行非交换态钾的释放特性研究,5种矿物非交换态钾3d释放累积量顺序为:黑云母 蛭石 金云母 白云母 钾长石;非交换态钾平均释放速率也表现为同样的顺序。上述5种矿物在弱提取力的四苯硼钠溶液中释放3 d,非交换态钾的平均释放速率分别为5.99、2.34、0.52、0.22和0.17 mg/(kgmin),差异明显。如何根据非交换态钾的释放量和释放速率来综合评价矿物钾的生物有效性是未来研究中需要明确的问题。     

富钾植物籽粒苋(Amaranthus spp.)对土壤矿物钾的吸收利用研究

运用土培、石英砂培、有机酸释钾实验及矿物X衍射分析研究了不同基因型籽粒苋(Amaranthusspp.)对土壤矿物钾的吸收利用及其机制。结果表明,籽粒苋能有效地利用土壤和云母(黑云母和金云母)中的钾;籽粒苋品种R104、CX4对钾的吸收量高于一般型品种(CX77);籽粒苋根系能引起云母矿物向蛭石转化;籽粒苋根系分泌物中的草酸比一般有机酸具有更高的释放矿物中钾素的能力。     

吉林省主要耕作土壤中钾的固定与释放

通过X—射线衍射、室内模拟实验及常规分析研究了吉林省主要耕作土壤中钾的固定与释放。结果表明,土壤对钾的固定与释放与土壤的矿物组成有关,3种土壤的固钾量均随钾加入量的增加而增大,而固钾率则随施钾量的增加而逐渐下降。随钾加入量的增加,固钾量和固钾率均有黑土>白浆土>黑钙土的趋势。土壤释钾量有黑钙土>黑土>白浆土的趋势。相关分析表明,蒙脱石、蛭石为主要的固钾矿物,而伊利石为主要的释钾矿物。     

肥田萝卜、油菜对金云母中矿物钾的活化与利用

本试验以金云母作为植物的唯一钾源,研究了缺磷与正常供磷条件下肥田萝卜、油菜对矿物结构钾的利用。结果表明,缺磷条件下两种植物每盆的吸钾总量( 肥田萝卜14-96mg ,油菜12-88mg) 以及矿物钾的净释放量( 肥田萝卜6-22mg ,油菜4-32mg) 均显著高于正常供磷处理的植物吸钾总量( 肥田萝卜11-90mg,油菜9-57mg) 和矿物钾净释放量( 肥田萝卜3-72mg,油菜3-07mg) 。同时,对根际金云母进行X光衍射扫描,结果发现两种处理的肥田萝卜和油菜的根际金云母均出现了明显的蛭石化现象,其中缺磷条件下两种植物引起的蛭石化作用较正常供磷的处理更显著。     

肥田萝卜、油菜对金云母中矿物钾的活化与利用

本试验以金云母作为植物的唯一钾源,研究了缺磷与正常供磷条件下肥田萝卜、油菜对矿物结构钾的利用。结果表明,缺磷条件下两种植物每盆的吸钾总量( 肥田萝卜14-96mg ,油菜12-88mg) 以及矿物钾的净释放量( 肥田萝卜6-22mg ,油菜4-32mg) 均显著高于正常供磷处理的植物吸钾总量( 肥田萝卜11-90mg,油菜9-57mg) 和矿物钾净释放量( 肥田萝卜3-72mg,油菜3-07mg) 。同时,对根际金云母进行X光衍射扫描,结果发现两种处理的肥田萝卜和油菜的根际金云母均出现了明显的蛭石化现象,其中缺磷条件下两种植物引起的蛭石化作用较正常供磷的处理更显著。     

土壤含钾矿物的释钾研究进展

介绍土壤中含钾矿物的类型、结构特点、钾素含量与钾素释放的关系,区分了含钾矿物在土壤中的构成及分布特点,同时对国内外关于含钾矿物钾素释放规律的研究状况,钾素释放的作用机理、动力学特性,以及影响土壤含钾矿物钾素释放的因素做了综述。     

不同土壤钾素释放动力学及其供钾特征的研究

应用自行研制的连续流动交换仪研究了取自不同类型的19个土壤样品的钾素释放动力学及其供钾特征。不同土壤钾的释放差异很大,钾的释放持续时间变幅为100～600分钟;最大释放速率变幅为0.46～20.55毫克千克-1分-1;平均释放速率变幅为0.009～1.25毫克千克-1分-1;总释放量变幅为40～430毫克千克-1。供试土壤钾的释放过程可以用一级反应方程拟合,表明钾的释放速率主要受交换位上钾离子饱和度的影响。应用一级方程计算出钾的释放速率常数变幅为5.4810-3～65.6210-3分-1。多数土壤的钾释放过程符合单一的一级反应;而以云母类为主,且含有部分绿泥石的土壤的钾释放过程由两个速率不同的一级反应构成,表明不同吸附位上的钾离子可能有不同的释放机制。用供试土壤连续种植玉米幼苗57茬进行土壤钾素耗竭试验,结果表明应用连续流动交换仪研究得出的土壤钾素释放的动力学参数可以较可靠地评价土壤的供钾特征。释钾速率快,持续时间长,总释放量大的土壤(如青海栗钙土),在耗竭试验中显出很强的供钾能力;而释钾速率慢,持续时间短,总释放量小的土壤(如广东砖红壤)在盆栽试验中供植物吸收的钾量很低。有的土壤(如四川紫色土)钾的总释放量不低,但释放速度快,持续时间短,在盆栽试验     

亚热带花岗岩地区土壤矿物风化过程中盐基离子的释放特征

矿物风化过程中盐基离子释放遵从一定的化学计量关系,这种化学计量关系一般只能通过模拟实验来获取。本研究采用pH 7.0的EDTA-乙酸铵溶液将土壤中的交换性盐基离子完全洗脱出来,然后用Batch方法模拟不同pH溶液淋溶洗脱盐基和未洗脱盐基土壤,旨在消除土壤中交换性盐基离子的影响后更为准确地判断土壤矿物风化的盐基离子释放特征。结果表明:未洗脱盐基土壤的淋出液pH由3.73±0.14逐渐上升到4.23±0.06,主要原因是淋溶液中有高浓度的NH_4~+;洗脱盐基土壤矿物风化后淋出液pH从7.39±0.02逐渐下降到5.39±0.17,主要是由于土壤中可风化矿物减少。土壤交换性盐基离子会改变盐基离子释放特征、释放总量:未洗脱盐基土壤经酸雨淋溶后,各盐基离子释放均呈现急速下降后逐渐平缓的趋势,洗脱盐基土壤矿物风化后,K~+及盐基离子释放总量呈波动上升趋势,且盐基离子释放总量比未洗脱盐基土壤低。土壤交换性盐基离子的存在还会改变淋出液中的盐基离子化学计量关系:未洗脱盐基土壤的K~+︰Ca~(2+)︰Mg~(2+)︰Na+化学计量关系为11︰13︰4︰1(当量比),而洗脱盐基土壤为7︰2︰2︰1。K~+是盐基离子中风化释放量最多的,大部分K~+来自于土壤中云母的风化。因此,只有利用洗脱盐基土壤的盐基离子释放量才能准确计算矿物风化速率并获得准确的化学计量关系。土壤矿物风化作用随着淋溶液酸度增大而增强,但模拟一年降雨量的情况下,p H 3.5、4.5和5.5三种不同p H溶液对矿物风化后盐基离子的释放在实验期间没有显著性影响,较长时间后的差异性有待观察。本研究表明,可以通过预洗脱盐基土壤然后模拟酸雨淋溶的方法,观察矿物风化特征,特别是盐基离子释放的化学计量特征。     

有机酸影响矿物钾释放的室内试验与数学模拟

在生物试验的基础上 ,利用连续流动法 ,模拟植物根系分泌有机酸的种类和数量 ,研究了不同有机酸对矿物钾释放的影响。结果表明 ,有机酸能够明显地促进矿物中钾的释放 ,浓度越高 ,释钾作用越明显 ;此外 ,其释钾能力还与有机酸的种类、矿物类型密切相关。对试验结果进行了随机数学模拟 ,表明所采用的传递函数模型能够较好地仿真矿物钾的释放过程。     

不同条件下硅酸盐细菌对含钾矿物分解作用的研究

研究了淹水、湿润和干燥条件下接菌与未接菌对含K矿物钾长石和页岩分解作用的影响。结果表明,在干燥条件下,硅酸盐细菌不能分解供试矿物释放出其中的K和Si;湿润或淹水条件下,硅酸盐细菌能显著加快供试矿物的分解而释放出K和Si,其中硅酸盐细菌NBT菌株分解矿物释放K的效果好于NFT-2菌株,而NFT-2菌株释放Si的效果优于NBT菌株。淹水条件下,28℃恒温静置培养40天后,NBT菌株从矿物中累积释放的K量占矿物中K含量的7.3%(钾长石)和10.2%(页岩),分别比对照组K释放量增加221%(钾长石)和232%(页岩);NFT-2菌株从矿物中累积释放的Si量占矿物中Si含量的11.6%(钾长石)和13.2%(页岩),分别比对照组Si释放量增加170%和190%。硅酸盐细菌分解含K矿物的作用与其代谢活性有关。     

不同林龄白桦次生林降雨水化学特征研究

通过对不同林龄白桦次生林林外降雨、穿透雨、树干茎流和枯透水中的Cl~-,NO_3~-N,Na~+,K~+,Ca2-,Mg~(2+)等进行测定,以研究4个林龄之间降水化学性质的差异.结果表明:林外降雨中Ca~(2+)的含量最高,Na~+含量最低,养分元素平均含量(以mg/L计)排列顺序为:Ca~(2+)>Cl~->K~+>NO_3~--N>Mg~(2+)>Na~+,各元素在林外降雨中的季节变化较大.变化幅度最小的是Cl~-;穿透雨中NO_3~--N,Ca~(2+)含量在25 a白桦次生林中最低,Cl~-,Mg~(2+)含量在38 a中最低,而Na~+,K~+含量在56 a中最低;树干茎流中Cl~-,NO_3~--N,K~+含量在38 a白桦次生林中最低,而Na~+,Ca~(2+),Mg~(2+)含量在56 a中最低;枯透水中Cl~-,NO_3~--N,Na~+,K~+含量在25 a白桦次生林中最低,Mg~(2+)含量在38 a中最低,而Ca~(2+)含量在56 a中最低.     

草酸对土壤和矿物中钾素的释放规律研究

Oxalic acid plays an important role in improving the bioavailability of soil nutrients. Batch experiments were employed to examine the influences of oxalic acid on extraction and release kinetics of potassium （K） from soils and minerals along with the adsorption and desorption of soil K^＋. The soils and minerals used were three typical Chinese soils, black soil （Mollisol）, red soil （Ultisol）, and calcareous alluvial soil （Entisol）, and four K-bearing minerals, biotite, phlogopite, muscovite, and microcline. The results showed that soil K extracted using 0.2 mol L^-1 oxalic acid was similar to that using 1 mol L^-1 boiling HNO3. The relation between K release （y） and concentrations of oxalic acid （c） could be best described logarithmically as y = a ＋ blogc, while the best-fit kinetic equation of K release was y = a ＋ b√t, where a and b are the constants and t is the elapsed time. The K release for minerals was ranked as biotite 〉 phlogopite 〉〉 muscovite 〉 microcline and for soils it was in the order： black soil 〉 calcareous alluvial soil 〉 red soil. An oxalic acid solution with low pH was able to release more K from weathered minerals and alkaline soils. Oxalic acid decreased the soil K^＋ adsorption and increased the soil K^＋ desorption, the effect of which tended to be greater at lower solution pH, especially in the red soil.     

Desorption and Transformation of Nitroaromatic (TNT) and Nitramine (RDX and HMX) Explosive Residues on Detonated Pure Mineral Phases

Explosive compounds, including known toxicants 2,4,6-trinitrotoluene (TNT) and hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), are loaded to soils during military training. Their fate in soils is ultimately controlled by soil mineralogical and biogeochemical processes. We detonated pure mineral phases with Composition B, a mixture of TNT and RDX, and investigated the fate of detonation residues in aqueous slurries constructed from the detonated minerals. The pure minerals included Ottawa sand (quartz and calcite), microcline feldspar, phlogopite mica, muscovite mica, vermiculite clay, beidellite (a representative of the smectite clay group), and nontronite clay. Energy-dispersive X-ray spectrometry, X-ray diffraction, and gas adsorption surface area measurements were made of the pristine and detonated minerals. Batch slurries of detonated minerals and deionized water were sampled for 141?days and TNT, RDX, and TNT transformation products were measured from the aqueous samples and from the mineral substrates at day?141. Detonated samples generally exhibited lower gas adsorption surface areas than pristine ones, likely from residue coating, shock-induced compaction, sintering, and/or partial fusion. TNT and RDX exhibited analyte loss in almost all batch solutions over time but loss was greater in vermiculite, beidellite, and phlogopite than in muscovite and quartz. This suggests common phyllosilicate mineral substrates could be used on military training ranges to minimize off-site migration of explosive residues. We present a conceptual model to represent the physical and chemical processes that occurred in our aqueous batches over time.     

The dissolution of micas by fulvic acid

Three micas commonly occurring in soils, that is, biotite, phlogopite and muscovite, were shaken with 0.2% (W/V) aqueous fulvic acid (FA) solution for 710 h at room temperature. Proportions of major constituent elements extracted (Fe, Al, Mg, K and Si from biotite, Al, Mg, K and Si from phlogopite and Al, K and Si from muscovite) were determined.Depending on the type of mineral and its Fe content, substantial amounts of Fe, Al, Mg, K and Si were brought into aqueous solution by the FA under mild conditions. The ease with which the micas were attacked by the FA decreased in the following order: biotite > phlogopite > muscovite. IR and ESR analyses indicated the formation of metal—FA complexes as a major reaction mechanism by which the minerals were dissolved. Our data show that aqueous FA solution can dissolve from micas relatively large amounts of metals and Si, which may then become more available to plant roots and microbes, active in soil genesis processes, as well as participants in the synthesis of new minerals.     

正常和高铵条件下氯化钠对万寿菊生长、开花和代谢的影响

在温室中以养分平衡的肥料组合和含250mg/L NH_4~+的组合栽培万寿菊(Tagetes patula L.)。每种组合中以一半植株每天每盆加250 mL 27.5 mmol/L NaCl溶液,进行盐胁迫处理。盐处理结果,使每株鲜重、株高和开花数都减少。盐处理2周后,根、叶细胞膜相对透性显著增加,叶子热处理渗出物中游离NH_4~+、根渗出物中Na~+。以及叶子中的过氧化物酶、Mg~(2+)-ATP酶和Ca~(2+)-ATP酶活性都明显提高,而根、叶渗出液的pH和蛋白质含量显著降低。根渗出物中游离NH_4~+、K~+和Ca~(2+)含量,叶子中叶绿素、可溶性蛋白质、无机磷和多酚氧化酶活性也下降,但未发现叶子渗出物中Na~+有所增加。在正常营养条件下,盐胁迫对叶子中的类胡萝卜素和花青素影响较小,但高NH_4~+处理使这些色素含量显著降低。高NH_4~+一般使NaCl的效应加剧。     

Effect of gypsum on potassium and iron release from phlogopite to alfalfa

This study evaluated the effects of gypsum on the release rate of potassium (K) and iron (Fe) from phlogopite to alfalfa under greenhouse conditions. The medium was a mixture of quartz sand as filling material, K- and Fe-bearing micaceous mineral (phlogopite) and different levels of gypsum (0%, 2%, 5%, 12% and 25%). During the 6-month cultivation period, the pots were irrigated and/or fed with distilled water and four different nutrient solutions. The results showed statistically significant effects of different levels of gypsum on dry weight and K and Fe concentration of shoots and roots. It seems that an increase in calcium (Ca) concentration, due to the addition of gypsum, changes the equilibrium of K and Fe in the root zone and plant tissues. The results of this study show that the rate of K and Fe release from micaceous minerals is extremely reduced in the presence of gypsum.     

Comparison of silicate minerals as sources of potassium for plant nutrition in sandy soil

Given the cost of conventional fertilizers and increasing demand as a result of increasing population growth, new sources of potassium (K) for plant nutrition need to be considered. Readily soluble nutrients are rapidly lost from well‐drained soils, and so it is appropriate to consider silicate minerals that release K slowly during weathering. In this paper, we compare the availability to plants grown in sandy soils of K from microcline (feldspar), biotite (mica) and nepheline syenite (nepheline + microcline) using leek (Allium ampeloprasum var. porrum L.) as a model plant. Pot experiments were carried out under controlled environmental conditions using natural and artificial soil. The performance of the minerals was compared with treatment with KCl and a negative control (no K added). Plant shoot diameter was measured weekly to assess growth rates. After 10 weeks, plant dry mass and soil and plant contents of soluble K were measured to determine offtake; mineralogical changes in biotite‐treated soils were assessed. Results for artificial and natural soil differed, reflecting differences in their mineralogy. With no added K, plant growth ceased after 2 weeks. Growth rates were greatest for KCl, followed by biotite; linear growth continued for 5 weeks in the natural soil and for the entire 10 weeks in the artificial soil. Growth rates with nepheline syenite (natural soil) and microcline (both soils) did not differ significantly from the negative control, but for nepheline syenite, leek shoot K content was significantly greater, demonstrating availability of K from this source. X‐ray diffraction analysis showed that biotite reacted to form vermiculite.     

水培条件下加入钾和硅减轻甘蔗盐胁迫效应

A hydroponics experiment was conducted to evaluate the role of potassium (K) and silicon (Si) in mitigating the deleterious effects of NaCl on sugarcane genotypes differing in salt tolerance. Two salt-sensitive (CPF 243 and SPF 213) and two salt-tolerant (HSF 240 and CP 77-400) sugarcane genotypes were grown for six weeks in ? strength Johnson’s nutrient solution. The nutrient solution was salinized by two NaCl levels (0 and 100 mmol L-1 NaCl) and supplied with two levels of K (0 and 3 mmol L-1) and Si (0 and 2 mmol L-1). Applied NaCl enhanced Na+ concentration in plant tissues and significantly (P ≤ 0.05) reduced shoot and root dry matter in four sugarcane genotypes. However, the magnitude of reduction was much greater in salt-sensitive genotypes than salt-tolerant genotypes. The salts interfered with the absorption of K+ and Ca2+ and significantly (P ≤ 0.05) decreased their uptake in sugarcane genotypes. Addition of K and Si either alone or in combination significantly (P ≤ 0.05) inhibited the uptake and transport of Na+ from roots to shoots and improved dry matter yields under NaCl conditions. Potassium uptake, K+/Na+ ratios, and Ca2+ and Si uptake were also significantly (P ≤ 0.05) increased by the addition of K and/or Si to the root medium. In this study, K and Si-enhanced salt tolerance in sugarcane genotypes was ascribed to decreased Na+ concentration and increased K+ with a resultant improvement in K+/Na+ ratio, which is a good indicator to assess plant tolerance to salt stress. However, further verification of these results is warranted under field conditions.