Extraction methods for aluminium and iron in relation to phosphate adsorption

Abstract

Three extraction methods for aluminium and two for iron were compared with phosphate sorptivity (Bache and Williams index) for 40 tropical and 40 British soil samples. Extractable aluminium was well correlated with phosphate sorptivity in both groups, but extractable iron was well correlated only in British soils. In general methods which extracted more sesquioxides gave higher correlation coefficients. With aluminium, N ammonium acetate (pH 4.8) or 0.1N HCl gave better correlation than N KCl, while with iron dithionitecitrate was better than 0.1N HCl.     

Determination of iron chlorosis with extractable iron analysis in peach leaves

Iron (Fe) though indispensable for the biosynthesis of chlorophyll, but its total content in the plant was not associated with the occurrence of chlorosis. Iron, which is the ferrous‐iron (Fe²⁺) form—termed “active”; Fe— and extracted with weak acids and some chelating agents, has been closely related to Fe chlorosis. In this study, three different methods were tested in order to determine suitable methods for extractable‐Fe analysis in a Dixired peach cultivar. In the first two methods, o‐phenantroline (o‐Ph) and 1N hydrochloric acid (HCl) were used to extract Fe²⁺ from fresh leaves. In the third method, 1N HCl were used as an extractant on dried leaf samples. The relationship between chlorophyll content of the leaves and Fe extracted by the three methods, was statistically significant. Hydrochloric acid extraction with dried leaves which gave the highest significant correlation (r = 0.930) with chlorophyll content, can be used for the determination of Fe²⁺ ("active”; Fe) status in peach trees.     

Use of 1,10‐phenanthroline in estimating metabolically active iron in plants

Abstract

If calcifuges are forced to grow on a calcareous soil, they usually develop chlorosis. However, total leaf iron (Fe) does not often correlate well with Fe deficiency symptoms. The extraction of ‘active’ Fe by 1 M HCl or Fe chelators, e.g., 1,10‐phenanthroline, may reflect the relation between chlorosis and Fe‐concentration in the leaves better than total Fe does. Extraction of ‘active’ Fe from leaves of wild plants by 1,10‐phenanthroline, citric acid and HC1 was compared. The 1,10‐phenanthroline was chosen for further methodological studies. All samples were extracted at indoor light conditions and analyzed by AAS because dark incubation did not influence the oxidation state of Fe and non‐specific light absorbance seemed to be high in colorimetric analysis. Washing of leaf material with H₂O seemed to clean the leaf surfaces equally well as with 0.1 M HCl. Only fresh leaf material was extracted, as pretreatment (freezing or drying) changed the extractability of Fe. An extraction time of 16 h was adequate for the herbaceous plants tested but not for Carex pilulifera, where extracted Fe increased linearly with time. The age of the extractant solution may play a role because 1,10‐phenanthroline had lost part of its chelation capacity after 6 weeks. The ratio of leaf weight:extractant volume did not influence the amount of Fe extracted, provided the same amount of chelator was supplied. The 1,10‐phenanthroline did not interfere with the Fe determination by AAS, and HCl pH 3 as used for the preparation of the extractants had only a marginal influence on Fe extractability compared to 1,10‐phenanthroline at pH 3. To get comparable results the extraction method should be standardized as much as possible. Samples can be stored in the refrigerator for several hours before adding the extractant and the extracts can be stored for a few days or frozen and measured on the same day, with the same instrument setting.     

ADVANCES IN DIAGNOSIS OF IRON DEFICIENCY IN AVOCADO

Several methods for determination of extractable iron (Fe; or so-called “active Fe”) have been proposed. In this study, three methods of Fe extraction were tested: 1.5% phenanthroline (pH 3) and 1 M hydrochloric acid (HCl) from fresh leaves, and 1 M HCl from oven-dry leaves. A six-year-old avocado orchard (cultivar ‘Hass’), grown on a calcareous soil in the proximity of Cabildo (Valparaíso region, Chile), was selected for the study. Samples of mature (5–7 moths-old) leaves of different degree of chlorosis were collected. Total Fe concentrations in chlorotic leaves were similar or even greater than in green leaves. Regressions between the extractable Fe concentrations and the leaf SPAD-color were statistically significant for phenanthroline method, while non-significant for HCl methods. Thus, phenanthroline method was superior over others for diagnosis of Fe deficiency in avocado. Phenanthroline-extractable Fe concentration of 6 mg kg^?1 was considered as a critical value for mature avocado leaves.     

Determination of suitable chemical extraction methods for the available iron content of brown forest soils in Turkey

The aim of this research was to determine the available iron (Fe) content of brown forest soils of Edirne Province and the most suitable chemical extraction method. Eight chemical extraction methods (the 0.005 M DTPA + 0.01 M CaCl2 + 0.1 MTEA, 0.05 M HCl + 0.012 M H2SO4, 1 M NH4OAc (pH: 4.8), 0.01 M EDTA + 1 M NH4OAc, 1 M MgCl2, 0.01 M EDTA + 1 M (NH4)2CO3, 0.005 M DTPA + 1 M NH4HCO3, and 0.001 M EDDHA methods) and six biological indices (the dry matter yield, Fe concentration, Fe uptake, relative dry matter yield, relative Fe concentration, and relative Fe uptake) were compared. The biological indices were determined with barley (Hordeum vulgare L.) grown under greenhouse conditions. At the end of the experiment, the highest correlation coefficients (r) were determined to be between the 0.005 M DTPA + 0.01 M CaCl2 + 0.1 M TEA method and the biological indices and between the 0.005 M DTPA + 1 M NH4HCO3 method and the biological indices. The corresponding correlation coefficients (r) for the 0.005 M DTPA + 0.01 M CaCl2 + 0.1 M TEA method and the six biological indices were 0.621**, 0.823**, 0.810** 0.433**, 0.558**, and 0.640**, respectively. For the 0.005 M DTPA + 1 M NH4HCO3 method, these coefficients were equal to 0.618**, 0.520**, 0.679**, 0.521**, 0.492**, and 0.641**, respectively (** indicate the validity of the relationships at p < 0.01) These extraction methods, out of all the methods tested, were suggested for the determination of the available Fe content of the brown forest soils. Published in Russian in Pochvovedenie, 2006, No. 9, pp. 1068–1074. The text was submitted by the author in English.     

Differential response of foliage plants to iron deficiency

Eight species of tropical foliage plants were screened to determine their response to Fe‐stress conditions. Plants were grown for 120 days in modified Hoagland's nutrient solution at pH 6.3 containing either 0, 0.22 or 5.52 mg/liter Fe (as Fe⁺³‐HEEDTA). Araucaria heterophylla and Dracaena marginata showed leaf chlorosis and decreased growth at 0 and 0.22 mg/liter Fe. Ficus benjamina and Nephrolepis exaltata ’Bostoniensis’ showed little or no chlorosis or growth differences at either 0 or 0.22 mg/liter Fe. Over a 3 week period, F. benjamina and N. exaltata ’Bostoniensis’ decreased nutrient solution pH approximately 1 to 1.5 units lower than either D. marginata or A. heterophylla at all Fe levels. Codiaeum variegatum var. pictum, Dieffenbachia maculata ’Camille’, Epipremnum aureum, and Philodendron scandens oxycardium were intermediate in growth, chlorosis and lowering of the nutrient solution pH. One explanation for the differential Fe response between these species may be their ability to lower pH of the rhizosphere.     

Comparison of Various Chemical Extraction Methods used for Determination of the Available Iron Amounts of Calcareous Soils

This study was conducted to compare the most appropriate method for the evaluation of available iron (Fe) status of calcareous soils by using nine different chemical extraction methods. Leaf and soil samples were collected from nine peach (Prunus persica L.) orchards, each of which included green, slightly chlorotic, and severely chlorotic peach trees. According to the chlorosis degrees of the leaves, total and active Fe contents and some soil properties were determined. Relationships between these parameters and Fe amounts obtained from the methods were correlated. Among the methods tested, method 3 (M3) [0.05 N hydrochloric acid (HCl) + 0.025 N sulfuric acid (H₂SO₄)] and method 8 (M8) 0.05 M ethylenediaminetetraacetic acid (EDTA) (pH 7.0) were the most suitable methods to indicate the available Fe status of the soils.     

树干高压注射铁肥矫正苹果失绿症及其机理

利用N-Fe、邻二氮杂菲铁和.59Fe作为铁源,以3-8年生富士／八棱海棠为试材进行主干强力高压注射试验。结果表明,铁肥树干强力高压注射,主要以二价铁(Fe2+)沿中央木质部的导管运输,大部分向下运输,使铁在根中大量贮存;向上运输较少,运输速度为每小时数百厘米,矫正缺铁失绿症的速度比根系输液慢,但由于根中贮存大量的铁,持效期较长。主干强力高压注射产生肥害的机理是先使吸收根中毒,然后导致叶片枯萎,提高注射部位,提高注射液浓度和减少注射的用药量,可以防止或减轻肥害的产生。     

Estimating non‐crystalline and crystalline aluminum and iron by selective dissolution in a riparian forest soil

Abstract

We compared sequential and separate extraction procedures for estimating non‐crystalline and crystalline aluminum (Al) and iron (Fe) in a floodplain forest soil. We used 0.2M acid ammonium oxalate (pH 3.0) to estimate non‐crystalline Al and Fe, dithionite‐citrate‐bicarbonate to estimate crystalline Fe, and 0.1M sodium hydroxide (NaOH) to estimate crystalline Al. Both separate and various combinations of sequential extractions were compared, as well as variations in soil:solution ratio, extraction time, extraction temperature, and the use of field‐moist versus dried soils. A sequential oxalate/NaOH extraction, using 0.4 g dry weight equivalent of field‐moist soil and a soil:solution ratio of 1:100, gave the best estimate of non‐crystalline Al and Fe and crystalline Al, while a separate 16 hour DCB extraction at room temperature, using 0.8 g dry weight equivalent of field‐moist soil and a soil:solution ratio of 1:50, gave the best estimate for non‐crystalline plus crystalline Fe. A sequential oxalate/NaOH extraction followed by a separate DCB extraction is a relatively simple procedure for estimating amounts of non‐crystalline and crystalline Al and Fe in large numbers of soil samples.     

Aluminum tolerance and micronutrient accumulation in cereal species contrasting in iron efficiency

Aluminum (Al) negatively interferes with the uptake or transport of different nutrients. The aim of our work was to compare the Al tolerance and micronutrient accumulation: iron (Fe), zinc (Zn) and manganese (Mn), in cereal species (winter wheat, spring wheat, winter rye, oats and barley) contrasting in Fe efficiency. Our previous screening in a calcareous soil showed that oats and barley were more Fe-efficient than spring wheat, winter wheat or winter rye. In Al stress conditions, both oats and barley exhibited more effectiveness in Fe acquisition and translocation from root to shoot in comparison to winter wheat, spring wheat and winter rye. Also, oats and barley responded to Al toxicity by less Al-retarded shoot biomass than other cereal species. A combination of tolerance mechanisms appears to have great importance for Al tolerance including mechanisms underlying Fe efficiency in cereal seedlings.     

Phosphorous levels on the ability of an iron‐inefficient and an iron‐efficient corn inbred to take up iron from nutrient solution

Abstract

The Fe‐inefficient corn (Zea mays L.) inbred Ys₁/YS₁ was compared with the Fe‐efflcient WF9 inbred for ability to take up Fe from solution culture at different P levels. A high level of P depressed Fe uptake more in the Ys₁/Ys₁ than in the WF9 inbred. The Ys₁/Ys₁ roots were high in P.     

Sequential extraction methods for soil organic nitrogen

(pp. 833–841)

In order to learn the status of available soil nitrogen (N), two sequential extraction methods (A and B) were tested. Proposed methods are as follows.

(A) Extraction with water, KCl, acetic acid, 1/15 M phosphate buffer, sulfuric acid, and NaOH.

(B) Extraction with water, KCl, 0.01 M sulfuric acid, 0.1 M sulfuric, 0.2 M sulfuric acid and 0.4 M sulfuric acid.

1) NO₃-N was only detected in a solution extracted with water. Major N in an extract with KCl was in ammonium form. Extracts with phosphate buffer and sulfuric acid contained organic-N only. When these two fractions were examined by size exclusion chromatography (HPLC-SEC), only one major peak in each extract appeared.

2) Minerals, such as Al and Fe in each extract were determined using ICP (Varian Co., Ltd.). With the increase in concentration of sulfuric acid, the high Fe concentration in each extract increased. On the other hand, much higher Al was found in extracts with lower concentrations of sulfuric acid compared to Fe.

3) Though some crop species such as spinach and carrot show the potential to take up organic-N in a soil applied with organic matter, this sequential soil-nitrogen extraction method may be useful to evaluate availability of soil nitrogen fertility with more accuracy compared to conventional methods in the case of these superior crop species.     

Changes in nutritional homeostasis of Poncirus trifoliata and Ceratonia siliqua as a response to different iron levels in nutrient solution

Abstract

Iron (Fe) deficiency is a nutritional disorder in plants. Poncirus trifoliata is susceptible to Fe deficiency, but symptoms of Fe deficiency are rare in Ceratonia siliqua, a slow-growing species. Specimens of the two species were grown in nutrient solutions containing three Fe concentrations: without Fe (0?µM), 1?µM Fe, and either 10?µM Fe (for Ceratonia) or 40?µM Fe (for P. trifoliata). Growth, the degree of chlorosis, the plant mineral composition, and the activity of the root ferric chelate-reductase (FCR) were assessed. Ceratonia plants exposed to 1?µM Fe were efficient at using Fe in the synthesis of chlorophyll. The activity of FCR was enhanced in the total absence of Fe. In Poncirus a low activity of the FCR was observed in plants with no Fe. The balance between micronutrients in the Ceratonia roots was not affected with 1?µM Fe compared with the higher Fe concentration treatments.     

Influence of residual phosphate fertilizer on labile and extractable zinc in hawaii soils

Abstract

Zinc availability was studied using five soils from Hawaii which had histories of massive phosphorus applications. Heavy phosphate fertilization usually increased extractable Zn, irrespective of the extractant used. The extra extractable Zn associated with the added P probably came from Zn as an accessory element in the fertilizer. Treble superphosphate commonly used in Hawaii contains about 1400 ppm Zn. The Zn content of phosphate fertilizers must be considered before making statements about the effect of fertilizer P on Zn solubility and availability in soils.

Two solutions (0.1N HCl and 0.005M DTPA) were compared as Zn extractants for Hawaii soils. DTPA extracted less Zn than 0.1N HCl. Zinc extracted by repeated HCl treatment was more closely related to the labile Zn pool (E‐values and L‐values) than was DTPA‐extractable Zn. The results suggest that 0.1N HCl extractable Zn, Zn E‐value and Zn L‐value measured the quantity of a single fraction of soil Zn.

Repeated extraction of soil with 0.1N HCl seems to be a suitable procedure for evaluating the Zn status of acid, highly weathered soils of Hawaii.     

Hydrochloric acid (0.1M) and dtpa extractable and total iron and manganese in basaltic soil profiles of the Nigerian savanna

Abstract

The contents of 0.1 M HCl and DTPA extractable and total iron (Fe) and manganese (Mn) were determined in soil profiles developed on four groups of basaltic parent materials, namely, the Newer‐, Older‐, Lateritized‐Older‐, and Biu‐basalts. HCl‐and DTPA‐extractable and total Fe in the soils ranged from 15.0 to 66.3 mg/kg, 1.1 to 26. 7 mg/kg, and 4.50 to 10.50%, respectively, with corresponding means of 37.5 mg/kg, 9.5 mg/kg, and 7.33%. The corresponding forms of Mn ranged from 1.1 to 89.0 (mean, 39.8) mg/kg, 0.3 to 114.7 (mean, 24.3) mg/kg and 34 to 1010 (mean, 346) mg/kg, respectively. The soils were high in total Fe and Mn and sufficient in the available forms (HCl‐and DTPA‐extractable forms). Total Fe and Mn were neither related to the available forms or to soil properties tested. The available forms were, however, related one with another and largely associated with organic matter.     

Determination of suitable chemical extraction methods for available zinc content of paddy soils at Thrace Region

This research was carried out in order to determine the zinc status of the paddy soils with different physical and chemical properties of Thrace region as well as to determine the most suitable method for chemical extraction of available zinc content of soils for plant. As a result of the investigation with 12 paddy soils representing the region, it was estimated that the application of increasing amounts of zinc to the soil of pot grown maize to increasing the zinc uptake, dry matter and zinc content of the plant was determined. Nine chemical extraction methods for available zinc contents of soil were used and the reliability of the investigated methods was ranked as: 0.005 r M DTPA+0.01 r M CaCl 2 +0.1 r M TEA; 0.005 r M DTPA+1 r M NH 4 HCO 3 ; 0.01 r M Na 2 EDTA+1 r M (NH 4 ) 2 CO 3 ; 0.01 r N Na 2 EDTA+1 r N NH 4 Oac; 0.01 r N Na 2 EDTA; 1 r N NH 4 Oac; 2 r N MgCl 2 ; 0.05 r N HCl+0.025 r N H 2 SO 4 ; 0.01 r M Hidrocinon. The method for extraction with 0.005 r M DTPA+0.01 r M CaCl 2 +0.01 r M TEA solution which not only owns the highest correlation coefficient but also enables determination of Fe, Mn and Cu concentrations in addition to Zn amount, could be recommended as the most suitable one for the investigated soils.     

Improvement of the NH2OH-HCl-HOAc method for extracting manganese and iron oxides in Japanese Andisols and other soil types in Japan

Abstract

We evaluated the validity of Tessier’s method as applied to the extraction of manganese (Mn) and iron (Fe) oxides in Japanese Andisols and other soil types in Japan. Using the original Tessier’s extractant mixture, 0.04 mol L^?1 hydroxylamine hydrochloride in 25% acetic acid (0.04 mol L^–1 NH₂OH-HCl in 25% HOAc), we found that substantial amounts of short-range-ordered Fe oxides were not extracted from allophanic Andisol samples and that considerable amounts of total Fe oxides were not extracted from all soil types. Relatively high extraction pH and large amounts of short-range-ordered Fe oxides in the Andisol samples might be responsible for incomplete extraction. Stoichiometric calculation indicated that the concentration of NH₂OH-HCl might be insufficient for complete extraction of Fe oxides. The extracted amounts of Mn and Fe increased with increasing concentration of NH₂OH-HCl in the extractant, and most of the Mn and Fe oxides in the soil samples, including samples with as much as 5.6% Fe, were extracted with 0.6 mol L^–1 NH₂OH–HCl in 25% HOAc. As judged from the simultaneous dissolution of aluminum (Al) and silicon (Si) minerals, extraction selectivity of Fe oxides with 0.6 mol L^–1 NH₂OH-HCl in 25% HOAc was comparable to that of the original Tessier’s method and better than that of a modified Community Bureau of Reference (BCR) sequential extraction procedure or a method using an extractant consisting of a mixture of oxalate and ascorbate, especially for Andisol samples.     

淹水后可变电荷土壤铁锰形态的转化

Ectomycorrhizal fungus Laccaria bicolor S238N,isolated from a forest soil in central France in 1990s,has demonstrated unequivocally and ability to promote pine growth.In the present nursery bed experiment,the ability of this ectomycorrhizal fungus to increase growth and P and K uptake of Douglas Fir seedlings (Zone 22) was examined.Growth of inoculated seedlings was over twice(plant height) and three times (biomass)that of non-inoculated ones.Similarly,both the concentrations and the amounts of P and K uptake by seedlings were significantly increased by fungal inoculation,indicating the improvement of P and K nutrition in mycorrhizal seedlings.In contrast,Al-P in the soils was decreased obviously by plants,especially by mycorrhizas,suggesting utilization of this soil P pool by plants and more efficient Al-P mobilization by mycorrhizas than by nomycorrhizas.Moreover,K extracted by 1mol/L HCl following consecutive extraction of H2O and CH3COONH4,which may not be plant available,could be utilized by fungus colonied roots.This could be explained by the release of protons and oxalate by hypae which leads to replacement of interlayer K in nonexpanded 2:1 clay minerals and bio-weathering of phyllosilicates.     

A study on the improvement iron nutrition of peanut intercropping with maize on nitrogen fixation at early stages of growth of peanut on a calcareous soil

Abstract

A glasshouse study employing a split-root technique was conducted to investigate the influence of intercropping with maize (Zea mays L.) in a calcareous soil on N₂ fixation by peanut (Arachis hypogaea L.) at early stages of growth. In this intercropping system, competitive interactions between maize and peanut for N and improvement of Fe uptake were likely to be important factors affecting N₂ fixation of peanut. The experiment was comprised of three treatments which included treatment I: peanut monocropping; treatment II: maize/peanut intercropping (the major and the minor compartments with low N, 50 mg kg^?1); treatment III: maize/peanut intercropping (the major compartment with low N, 50 mg kg^?1 and the minor compartment with high, N 200 mg kg^?1). The minor compartment of treatment III was fertilized with 200 mg kg^?1 N for reducing or eliminating the competition of N coming from intercropping maize. Intercropping with maize corrected Fe chlorosis of peanut by significantly increasing plant Fe concentration and uptake. Compared with the monocropping treatment, iron uptake increased from intercropping treatment II and III by 22 and 24% per plant, 30 and 29% shoots, 38 and 60% nodules. Iron uptake by the root nodules was especially enhanced in the intercropping system. In contrast, intercropping with maize had little effect on NO₃ ^?1-N concentrations in the soil rhizosphere of peanut or on N concentrations and uptake by peanut compared with plants in monoculture. The results indicate that the improvement in Fe nutrition was an important factor promoting N₂ fixation by peanut in the intercropping system at the flowering stage of peanut growth, and that competition for N by intercropped maize had little effect on N₂ fixation by peanut under the experimental conditions.     

Comparative study on the effectiveness of several iron compounds in the iron chlorosis correction in citrus plants

A comparative study was carried out on the effectiveness of several commercial Fe‐compounds applied through the soil as well as via leaf spray, with a view to control the Fe‐chlorosis in Verna lemon trees directly grafted on sour orange rootstock, with a Salustiano orange tree as intermediate. The results obtained during 1985 confirm the conclusions of previous experiments: The most effective treatments were the leaf spray with Fe‐polyflavonoids, though it is interesting that Fe‐chelates applied to soil were also highly effective, as Fe leaf levels were higher than 100 ppm one month after treatments.