Amelioration of Aluminum Toxicity by Pretreatment with Phosphate in Aluminum‐Tolerant Rice Cultivar

Abstract

The phytotoxicity of aluminum (Al) in relation to preculture with phosphates was examined in the rice cultivar Arkansas fortuna. In plants precultured with phosphates, Al did not inhibit shoot growth, while Al retarded shoot growth in plants precultured without phosphates. In contrast, Al inhibited root elongation, irrespective of the presence of phosphates in the preculture solution. A large proportion of the Al in roots was in unknown, insoluble forms. In phosphate‐precultured plants, Al deposition was slightly increased, presumably due to the formation of aluminum phosphates in the roots, and phosphorus levels in shoots were markedly increased. Binding with phosphates may ameliorate the toxicity of Al when it enters the shoots and account for the uninhibited shoot growth in the presence of Al in plants precultured with phosphates.     

Solution 31Phosphorus Nuclear Magnetic Resonance Analysis of Acid-Extractable Phosphates in Animal Feces

Characterizing phosphates in animal fecal and manure samples is of interest to environmental-monitoring research efforts. Acid extraction removes relatively mobile phosphates from samples, offering a better indicator of the mobility of phosphates in environment, but acidic extracts impose challenges to the solution phosphorus-31 nuclear magnetic resonance (³¹P NMR) spectroscopy, which is commonly used for analyzing phosphates in environmental samples. Acid-extractable metals precipitate phosphates in the alkaline condition under which solution ³¹P NMR experiment runs, blurring the spectrum for adequate analysis. We found that neutralizing acid extracts with 0.5 M sodium hydroxide (NaOH) plus 50 mM ethylenediaminetetraacetic acid (EDTA) before freeze drying eliminated the chemical interferences otherwise observed. The resulting ³¹P NMR spectra can be used to quantify acid-soluble phytate and other phosphates in animal fecal and manure samples. The improvement in detection will support efforts to investigate the mobility of phosphates in feces and manures used as land amendments.     

Effects of Inorganic Phosphates on the Thermodynamic,Pasting, and Asian Noodle‐Making Properties of Whole Wheat Flour

The effects of four inorganic phosphates on the thermodynamic and pasting properties of whole wheat flour as well as color, cooking quality, textural properties, and structural characteristics of whole wheat noodles were studied. The addition of phosphates increased the gelatinization temperature and enthalpy of melting of starch in whole wheat flour. Rapid visco analysis showed that all phosphates significantly increased whole wheat flour peak viscosity and final viscosity. Moreover, the whole wheat noodles prepared with disodium phosphate, trisodium phosphate, and sodium tripolyphosphate (STPP) exhibited brighter appearance, and the use of STPP and sodium hexametaphosphate reduced the cooking loss of whole wheat noodles. Texture profile analysis of cooked noodles revealed that the addition of phosphates significantly decreased the hardness and slightly increased the springiness, cohesiveness, and resilience. The microstructure of whole wheat noodles showed a larger degree of connectivity of the protein network and coverage of starch granules in the presence of inorganic phosphates. The results suggested that inorganic phosphates exhibited substantial effects on improving the quality of whole wheat noodles. Of the four phosphates studied, STPP appeared to be the most effective one in improving the overall properties of whole wheat noodles when they were normalized to constant phosphate content.     

Die Phosphatmobilität im Hochmoorboden in Abhängigkeit von der Düngung

Phosphate mobility in relation to fertilizing effects in raised-bog peat The phosphate solubility of raised-bog peat soils is very different from the phosphate solubility of mineral soils. Compared to mineral soils the losses of phosphates by leaching are 10 to 20 times higher. This mobility of phosphates is destined by the quantity, kind and time of fertilizing, land use (grassland or arable land) and fertilizing technique. Field and lysimeter trials with raised-bog peat soils show: 1. Water soluble phosphates are quickly translocated and leached. 2. Water insoluble phosphates are quickly solved and leached in raised-bog peat soils. The mobility of the phosphates decreases with increasing pH-value of the top soil and topdressing. At a pH-value of 4,O nearly 80% of Thomasphosphat and nearly 70% of Hyperphos phosphates are leached in lysimeter trials; at pH-value of 4 3 only 17 % of Thomasphosphat and 15 % of Hyperphos phosphates are leached. 3. To minimize leaching losses phosphate fertilizingin spring is recommended to reduce the phosphate leaching. 4. The phosphate leaching in grassland is twice or thrice less than in arable land.     

A菌根真菌外生菌丝对难溶性无机磷酸盐的活化及利用Ⅰ.~(32)P间接标记法

采用三室栽培装置培养三叶草 ,接种VA菌根真菌Glomusmosseae。将根系与VA菌根真菌外生菌丝隔开 ,在菌丝室施用 5种磷酸盐和32 P间接标记磷肥 ,研究外生菌丝对难溶性磷酸盐的活化利用能力。结果表明 ,外生菌丝可以活化吸收磷酸二钙、磷酸八钙、磷酸铝和磷酸铁 ,无法活化利用磷酸十钙 ;各种磷酸盐被活化吸收的量及其对三叶草磷营养的贡献率的大小顺序是磷酸二钙 >磷酸八钙、磷酸铝 >磷酸铁     

酸性硫酸盐土壤上几种磷矿粉对水稻生长的影响

在酸性硫酸盐土壤未垦和已垦地上进行的磷矿粉田间试验结果表明，未垦地上直接施用磷矿粉对水稻有显著的增产作用，主要表现在促进水稻株高、分蘖数、穗数的增加上．但在已垦地上磷矿粉对水稻的增产作用不甚明显．施肥后对相关的土壤肥力状况变化也进行了报道．     

Phosphorus Solubilization from Low-Grade Rock Phosphates in the Presence of Decomposing Soybean Leaf Litter

Abstract

The natural phenomenon of defoliation of mature soybean leaves onto the soil surface provides a large quantity of easily decomposable organic matter in the form of leaf litter. The potential of decomposing soybean leaf litter (SLL) to solubilize phosphorus (P) from two low‐grade rock phosphates, Jhabua rock phosphate (JRP) and Hirapur rock phosphate (HRP), alone or amended with pyrite, was assessed in an incubation study. Decomposing SLL solubilized P both from JRP and HRP and concurrently increased water‐soluble as well as organic P contents. Amending rock phosphates with pyrite (in a 1∶2 P to S ratio) promoted P solubilization. Approximately 71 to 92% of the total solubilized P was converted to organic P. The rate of P solubilization increased with SLL decomposition time, reaching its peak at 60 days with rock phosphates alone and at 90 days with pyrite‐blended rock phosphates. The maximum P solubilization (as a percentage of total P added) with different rock phosphates and their mixtures with pyrite followed this order: HRP (11.4%)<HRP+pyrite (16.5%)<JRP (20.2%)<JRP+pyrite (26.5%). These findings clearly suggest that the decomposing SLL has the potential to solubilize P from the otherwise insoluble low‐grade rock phosphates and can offer a natural opportunity for direct use of rock phosphates in the cropping systems that have soybean as a component crop.     

黑土无机磷形态及其有效性研究

采用顾、蒋提出的无机磷分级方法,对吉林省黑土进行了无机磷形态组成的研究。结果表明:供试黑土中60%～80%左右的磷以无机磷形式存在,其组成如下:O-P(16.25%～61.0%)>Fe-P(11.42%～38.63%)>Ca10-P(11.66%～34.48%)>Al-P(8.71%～23.77%)>Ca2-P(5.17%～22.51%)>Ca8-P(1.81%～27.19%)。利用相关分析和通径分析相结合的方法,研究比较了各组无机磷对有效磷的相对重要性,它们依次是:Ca2-P>Al-P>Fe-P>Ca8-P>O-P>Ca10-P。在吉林省黑土中Ca2-P是主要磷源,而Al-P、Fe-P是Ca2-P的有效补充。黑土中各形态无机磷的组成是相对稳定的,而且它们可以通过自身或者另外一方直接或间接地影响土壤中有效磷的含量。建立了Olsen-P与对其影响较大的二因子间的回归方程:y=2.433 0.466x1 0.134x3。     

OCCURRENCE OF INOSITOL PHOSPHATES AND OTHER ORGANIC PHOSPHATE COMPONENTS IN AN ORGANIC COMPLEX

A calcareous organic soil was extracted by shaking with Na⁺-resin suspended in 0·2M acetyl acetone at pH 8·3. Fractionation of the fulvic acid on Sephadex G 25 gave (a) a high molecular-weight component which contained inositol tetraand hexa-phosphates and a sugar phosphate; (b) low molecular-weight components which included the mono-, di-, and triphosphate esters of inositol and two sugar phosphates, but no free inositol phosphates. Inositol phosphates and sugar phosphates accounted for 30·2 per cent and 16·6 per cent of the soil organic P respectively. Our evidence indicates that these phosphate esters exist in an organic complex.     

DISTRIBUTION OF INOSITOL PHOSPHATES, PHOSPHOLIPIDS, AND NUCLEIC ACIDS AND MINERALIZATION OF INOSITOL PHOSPHATES IN SOME BANGLADESH SOILS

Concentration of inositol phosphates, phospholipids, and RNA and its derivatives of ten Bangladesh soils varied between 17.5 and 150 ppm, 0.5 and 11.0 ppm, and 0.22 and 1.30 ppm respectively. Variation in inositol phosphates was related to total phosphate and organic phosphate contents. Variation in phospholipids was associated with total phosphate, organic phosphate, and organic matter contents whereas the variation in RNA and its derivatives was related to total phosphate contents of the soils. Maximum mineralization of inositol phosphates was obtained in the first 30 days either when incubated with lime or when submerged under water. A moderate rate was observed in the subsequent 30-day incubation periods. The mineralization was greater in soil which contained more organic matter and inositol phosphates. Mineralization also increased with pH. Liming enhanced mineralization as it induced conditions for the proliferation of phosphate transforming organisms.     

改性磷矿粉在石灰性土壤上的生物有效性及其机理研究

为缓解磷资源危机,充分利用不适于化学加工的磷矿资源,对磷矿采用活化技术开发利用,由此生产的改性磷肥已被证明在酸性土壤上有很高的生物有效性,但在石灰性土壤上的研究还比较少。本文选择4种不同产地(云南昆明、四川德阳、四川绵竹和贵州开阳)的磷矿粉,分别用有机活化剂和无机活化剂进行活化处理,制备改性磷矿粉,并就其在石灰性土壤对苗期春小麦的生物有效性进行了盆栽试验。结果表明,4种磷矿粉经活化处理后有效磷和水溶性磷含量均明显增加,无机活化剂提高了有效磷的含量,而有机活化剂对水溶性磷的提高幅度较大。改性磷矿粉处理均不同程度提高了石灰性土壤上春小麦的生物量干重、植株吸磷量和磷利用效率,有机活化剂处理制备的改性磷矿粉对春小麦生长的促进作用更为明显。运用红外光谱谱学技术对4种磷矿粉及相应的8种改性磷矿粉结构分析结果表明,磷矿粉经改性后其结构发生了明显变化,H2PO4和HPO42的特征谱带明显增加,增加的程度因磷矿粉的产地和活化剂种类不同而有差异。对磷矿粉化学成分分析结果表明,不同产地的磷矿粉其磷以及钙、铁、铝、镁等化学成分的含量差异较大,活化剂对磷矿粉的活化效果与磷矿粉本身的氧化物含量有关。在本试验条件下,磷矿粉Ⅲ(四川绵竹)的活化效果相对最好,与其氧化镁含量最高、总氧化物含量最低有关。不同类型活化剂对磷矿粉的活化效果不同,红外光谱分析结果表明,无机活化剂活化效果较好,而土培试验结果表明有机活化剂的活化效果较好,这一结果有待进一步的研究。     

Is occluded phosphate plant‐available?

Background: The phosphate concentration of the soil solution is generally low, allowing sufficient plant nutrition only for a few days. Therefore, supply from various fractions of bound phosphate is essential to meet plant demand. It is known that plants have developed strategies to acquire phosphorus (P) from phosphates adsorbed on clay minerals or oxides, from organically bound phosphates, and from calcium phosphates. However, it is generally assumed that occluded phosphate is not plant‐available. Results: In a pot experiment, two plant species, namely maize (Zea mays L.) and white lupin (Lupinus albus L.), differing in acquisition efficiency, were used to investigate whether Al oxide‐occluded and Fe oxide‐occluded phosphates can be acquired. Artificially prepared Al oxide‐occluded phosphate or Fe oxide‐occluded phosphate, respectively, was added to a subsoil low in available phosphates. It is shown that both plant species were not able to acquire P from Al oxide‐occluded phosphate. Also, maize was incapable of using Fe oxide‐occluded phosphate. In contrast, white lupin took up significant amounts of P from Fe oxide‐occluded phosphate. Conclusion: It is concluded that the strategy to form cluster roots together with their reducing power may allow white lupin to destabilize Fe oxides that occlude phosphates and to mine the soil for this additional phosphate fraction.     

低分子量有机酸对石灰性土壤磷素形态转化及有效性的影响

采用室内培养和化学分析的方法研究了几种低分子量有机酸对石灰性土壤中磷的活化作用。结果表明:供试有机酸通过溶解、螯合等作用均能不同程度地促进合成磷酸盐的磷素释放。活化DCP、ODP、Fe-P、A l-P的能力依次为柠檬酸>草酸>苹果酸>酒石酸>乙酸;活化FA的能力是草酸>柠檬酸>苹果酸>酒石酸>乙酸。同种有机酸作浸提剂时,有机酸浓度越高磷酸盐中磷素释放量也越大。施加各种有机酸可以不同程度地降低土壤中Fe-P、A l-P和Ca10-P,增加Ca2-P、Ca8-P和O-P含量,总的趋势是促进土壤中植物难以利用的无机磷形态向有效性较高的形态转化。这种促进作用大小顺序为草酸>柠檬酸>酒石酸。     

Species of Inorganic Phosphate Solubilizing Bacteria in Red Soil and the Mechanism of Solubilization

INTRODUCTION The insoluble phosphates which can not be directly absorbed by plants are the mai forms of inorganic phosphate in soil. These kinds of phosphates can be solubilized by several species of bacteria which are widely spread in soil especially in rhizosphere where70% of the bacteria are capable of solubilizing inorganic phosphate.     

RELATIONSHIP OF INORGANIC PHOSPHATE FRACTIONS T O MINERALOGICAL CHANGES IN CALCINED CHRISTMAS ISLAND ROCK PHOSPHATE

A close relationship exists between inorganic phosphorus fractions and mineralogical changes in ‘C’-grade Christmas Island rock phosphate calcined at temperatures up to 1100 °C. Amounts of acid-extractable Ca-P closely followed the presence and crystallization of calcium phosphates. Amounts of NH₄F-P were related to the presence of simple aluminium phosphates. The ammonium fluoride reagent did not extract more complex aluminium phosphates such as crandallite and millisite. These minerals were considered to be present in the 2nd NaOH-P and residual-P fractions. NH₄F-P plus acid-extractable Ca-P was closely related to radish growth responses.     

Investigation into Heavy Metal Uptake by Waste Water Sludges

Preliminary studies conducted in our laboratory with composted sludge have shown that this material has a high affinity for metals. This metal uptake property appears to be particularly pronounced for lead, for which the material showed a retention capacity of 15% of its weight. The metal uptake process is accompanied by the release of an equivalent amount of calcium. Based on the results of this preliminary work, it appears that metal uptake by composted sludge involves phosphates. These phosphates may be associated with minerals, such as apatite, present in the sludge, and/or dead or living microorganisms, such as bacteria, also present in the sluge. It appears that calcium in the apatite is displaced by lead, forming lead phosphate mineral. On the other hand, the involvement of microorganisms can occur in three possible ways. It can involve phosphates associated with the biomass of dead bacteria and other organisms. It can also involve phosphates occurring in the system following microbial detoxification, a process which is believed to be accompanied by the release of inorganic phosphates. Lead uptake by bacteria can also be a genetic process.     

从不同浸提剂所浸出的磷酸盐形态探讨几种速效磷测定方法的意义

在前一报告中^[1],作者通过室内化学分析及生物试验证明,在所试的六种测定土壤有效磷的方法中,以Olsen的0.5M NaHCO₃法与生物反应的相关性最好,马乞金的1%(NH₄)₂CO₃法和Radet的3.5%柠檬酸钠法次之,Egner-Rim的乳酸钙法、Burriel-Hern-ando的混合浸提液法和Joret-Herbert的草酸铵法又次之。另外,从浸提出的磷量看,碳酸氢钠法、马乞金法和柠檬酸纳法相当接近,可以列为同一数量级。乳酸钙法、混合浸提液法和草酸铵法浸出的磷量也很接近,可以列为另一较高的数量级。     

Agrochemical assessment of bog phosphates in Western Siberia

Bog phosphates of Western Siberia were characterized; the agrochemical properties of vivianite in peat deposits were studied, and its positive effect on the phosphate pool of zonal soils was revealed. A high and prolonged effect of peat vivianite on the main agricultural crops was experimentally proved. It was shown that the wide use of bog phosphates as fertilizers offers much promise for the regional agriculture.     

THE NATURE OF ALKALI-SOLUBLE SOIL ORGANIC PHOSPHATES

Fractionation of the phosphates in a sodium hydroxide extract of an arable soil has shown the presence of a number of esters of a type not previously detected in soils. These included several mono-phosphorylated carboxylic acids with C to P ratios of approximately 7 or 8 to I and two esters each containing glycerol, myoinositol, chiroinositol and an unidentified component. Another ester, probably containing two phosphate groups, was also detected but was not completely separated from other compounds containing no P. These esters constituted only approximately 3 per cent of the total soil organic P but considerable losses of organic P occurred during the extraction and isolation procedures. The amounts of the inositol phosphates, nucleoside phosphates, and inorganic pyrophosphate in the extract were also measured.