Interaction between Plant Nutrients: II. Effect of Chloride on Activities of Cations in Soil Solution and on Nutrient Uptake by Plants

Abstract

In soil solutions the sum of cations is equivalent to that of anions. Anions are soluble or precipitated as less soluble salts. Therefore, the sum of soluble anions are responsible for the sum of cations in the soil solution. Soluble nitrate anions are unstable as they immobilize in biological materials. Hydrogen carbonate is excreted from plant roots and decomposes into carbon dioxide and carbonate. Carbonate reacts with hydrogen ions and forms complexes and ion pairs with calcium ions. Sulphate and chloride are more stable in the soil solution as anions.

Chloride ions were found to increase the activity of cations in the soil solution and to increase uptake of cations through the entire growth period. Increased absorption of cations increased yield. In temperate climate regions the surplus of chloride leaches from the root zone during winter.     

Loblolly pine plant community structure and soil solution aluminum,organic acids,calcium, magnesium,and pH

Abstract

Vegetative cover may influence soil chemical properties by producing organic acids that can modify the toxicity are responsible for high levels of nontoxic soil solution aluminum (Al). This study was conducted to determine the effect of loblolly pine (Pinus taeda L.) plant community structure, i.e., differing vegetative covers, on exchangeable cation distribution, and soil solution concentration of aluminum (Al) and organic acids. Soil was sampled were taken from 8‐year‐old forest plots with differing plant community structure (herbaceous‐hardwood‐pine, herbaceous‐pine, hardwood‐pine, and pine only), and measured for exchangeable cations. Soil solution extracts were analyzed for Al, organic acids, and the major cations and anions. There were significant differences in exchangeable Al, and calcium (Ca) among communities. Soil pH was highest in the herbaceous‐pine community, while other communities did not differ in soil pH. Oxalic, citric, malic, and succinic acids were detected in soil solution for all communities, but did not differ significantly among communities. Calculated Al activity was less than those determined by the 8‐hydroxy quinoline (15 sec) method. For these conditions, calculated Al activities did not change by accounting for the Ca‐ and magnesium (Mg)‐organic acid complex. The Al activities found were similar to previous reported levels that were considered nontoxic.     

Method for rapid assessment of nutrient supply capacity of soils

Abstract

A method to determine the nutrient supplying capacity of soils is presented which utilizes a nutrient solution in a lower container to supply designated nutrients to an upper container holding the soil. A series of nutrient solutions have been developed which maintain counter ion concentrations when a single nutrient is omitted from the solution. The validity of the technique is demonstrated by the agreement between plant yields, plant analysis data, and soil tests.     

Binding energies of monovalent anions with Fe/Al oxides based on ion activity and suspension Wien effect methods

Purpose  

Adsorption is one of the most important chemical processes at the interface between soil particles and water. It determines the quantities of plant nutrients and pollutants which can be retained on the surfaces of soil particles, and therefore, it is one of the primary processes that affect transport of nutrients and contaminants in soils. The Wien effect, i.e., the dependence of the electrical conductivity of soil suspensions on electrical field strength, has recently been proposed as the basis of a novel method to characterize energy relationships between cations and soil particles, but little attention has been paid to the binding energies of anions with soil particles. The aim of this study was to examine the Wien effect of three anions F⁻, Cl⁻, and NO₃⁻ in Fe/Al oxide suspensions and to investigate their binding energies with ion activity and Wien effect methods for comparison.     

Comparison of soil solution extraction procedures: Effect on solute chemistry

Abstract

A study was undertaken to evaluate the effect of five methods of soil solution extraction on solute chemistry. The methods evaluated were high speed centrifugation, immiscible displacement, column equilibration/vacuum extraction, and 1:1 and 2:1 solution:soil water extractions. Solutions were analyzed for pH, major cations and anions, silicon, and dissolved inorganic and organic carbon. Solute concentrations followed a general trend of centrifugation > immiscible displacement > column equilibration ≈2:1 extract ≈1:1 extract. Solution pH varied up to 3 units depending on the method employed. A significant soil type times method interaction also occurred indicating that the extraction methods differ with soil type. The coefficients of variation averaged over all solutes for each method ranged between 0.079 and 0.130. This study shows that the method of choice for a given experimental design must be carefully evaluated for each soil.     

A simple rapid method for the measurement of exchangeable cations and effective cation exchange capacity

Abstract

A simple single‐extraction procedure for measuring exchangeable cations and effective CEC (ECEC, the CEC at natural pH and ionic strength) has been developed for routine advisory soil analysis. The method is based on the use of Sr (1.26M SrCl₂) to displace exchangeable cations and effective CEC is taken as the sum of the exchangeable cations. A ten minute shaking time at 5 g:80 ml, soil solution ratio, was found to be optimum. Good agreement was found between the proposed method and the standard neutral IN ammonium acetate leaching procedure with correlation coefficients (r) for the individual cations Mg, Ca, Na and K of 0.99***, 0.99***, 0.83*** and 0.96*** respectively. Strontium chloride extracted more Al but less Mn (P<0.01) than IN KC1, but because of the low levels of these cations in relation to the total cations present, there was still a good relationship (r= 0.99) between ECEC determined by 1.26M SrCl₂ and that determined as the sum of ammonium acetate extractable Mg, Ca, Na and K plus IN KCl‐extracted Al and Mn.     

Effect of soil pH on cation and anion solubility

Abstract

The effect of soil pH on the exchangeability and solubility of soil cations (Ca, Mg, Na, K, and NH₄‐N) and anions (NO₃‐N, Cl, and P) was investigated for 80 soils, spanning a wide range in physical and chemical properties and taxonomic groups. This information is needed from environmental and agronomic standpoints to estimate the effect of changes in soil pH on leachability and plant availability of soil nutrients. Soils were incubated with varying amounts of acid (H₂SO₄) and base (CaCO₃) for up to 30 days. Although acid and base amendments had no consistent effect on cation exchangeability (as determined by neutral NH₄OAc), amounts of water‐soluble Ca, Mg, Na, K, NH₄‐N, and P decreased, while NO₃‐N and Cl increased with an increase in soil pH. The increase in cation solubility was attributed to an increase in the negative charge of the soil surface associated with the base addition. The change in surface electrostatic potential had the opposite effect on amounts of NO₃‐N and Cl in solution, with increases in N mineralization with increasing soil pH also contributing to the greater amount of NO₃‐N in solution. The decrease in P solubility was attributed to changes in the solubility of Fe‐, A1‐, and Ca‐P complexes. The logarithm of the amount of water‐soluble cation or anion was a linear function of soil pH. The slope of this relationship was closely related (R² = = 0.90 ‐ 0.96) to clay content, initial soil pH, and size of the cation or anion pool maintaining solution concentration. Although the degree in soil pH buffering increased with length of incubation, no effect of time on the relationship between cation or anion solubility and pH was observed except for NO₃‐N, due to N mineralization. A change in soil pH brought about by acid rain, fertilizer, and lime inputs, thus, affects cation and anion solubility. The impact of these changes on cation and anion leachability and plant availability may be assessed using the regression equations developed.     

Etude de la nutrition potassique du sorgho I‐ incidence du remplacement du potassium par le sodium sur la teneur en cations des feuilles

Abstract

Grain sorghum plants were grown in nutritive solution culture under variable potassium concentrations from 0.5 to 6.0 meq/l, Na replacing K in deficient solutions. Leaves were analysed for K⁺, Na⁺, Ca⁺⁺ and Mg⁺⁺.

Potassium deficiency has no effect on the total amount of cations, but the decrease of K in deficient leaves is correlated with an increase of Na⁺, Ca⁺⁺ and Mg⁺⁺. Evidence of antagonism between K and divalent cations in given, but, in the most deficient leaves, magnesium instead of calcium balances for the diminution of potassium.     

Factors Affecting the Formation,Nature, and Properties of Iron Precipitation Products at the Soil–Root Interface

Abstract

A number of iron oxides (hematite, goethite, lepidocrocite, maghemite, and magnetite) or short‐range ordered precipitates (ferrihydrite) may be found in soil environments, but in the rhizosphere the presence of organic ligands released by plants (exudates) or microorganisms promote the formation of ferrihydrite. Iron ions are liberated into soil solution by acidic weathering of minerals and then precipitated either locally or after translocation in soil environments. Humic and fulvic acids as well as organic substances produced by plants and microorganisms are involved in the weathering of primary minerals. Organic compounds play a very important role in the hydrolytic reactions of iron and on the formation, nature, surface properties, reactivity, and transformation of Fe oxides. Organic substances present in the rhizosphere interact with Fe promoting the formation of ferrihydrite and organo‐mineral complexes. The solubility of Fe precipitation products is usually low. However, the formation of soluble complexes of Fe(II) or Fe(III) with organic ligands, usually present in the rhizosphere increases the solubility of Fe‐oxides. Mobilization of Fe from Fe oxides by siderophores is of great importance in natural systems. They can form stable Fe(III) complexes (pK up to 32) and thus mobilize Fe from Fe(III) compounds. These higher Fe concentrations are important for the supply of Fe to plant roots which excrete organic acids at the soil–root interface. Iron oxides adsorb a wide variety of organic and inorganic anions and cations, which include natural organics, nutrients, and xenobiotics. There is competition between anions and cations for the surfaces of Fe‐oxides. Root exudates suppress phosphate or sulfate adsorption on Fe‐oxides. This is a mechanism by which plant roots mobilize adsorbed phosphate and improve their phosphate supply. Anions adsorption on iron oxides modify their dispersion/flocculation behavior and thus their mobility in the soil system. That can increase or decrease the possibility of contact between Fe‐oxides and organics or organisms able to dissolve them.     

Sample volume effect on determination of soil salinity

Abstract

Five pedons from a 200 hectare area were sampled to study the effect of the soil sample volume on determination of salinity. Four sample sizes, 5, 50, 500 and 5000 g, were used, with five to ten replicates each, for the top 25 cm of the profiles. These samples were prepared and analyzed for soil salinity, soluble cations and anions in 1: 2 (soil: water) extracts. Data revealed that the variations due to the different sample sizes were highly significant. Highest values of EC, cations and anions were obtained when using 5‐g samples. The confidence intervals tended to be lowest for the 5000‐g samples in most of the EC, cation and anion determinations. The 500‐g sample size was awkward and apparently the 5‐g sample size was too small.     

Soil Characteristics and Mineral Nutrient in Wild Jatropha Population of India

Abstract

Mature leaves of naturally occurring Jatropha curcas plants and soils samples were collected from four different populations to determine the soil characteristics, soil‐available nutrients, and leaf nutrient contents. This study provides a reliable account of the endogenic concentrations of nutrients present in jatropha leaves. Soil manganese [diethylenetriamine pentaacetic acid (DTPA)‐Mn] was the only soil‐available nutrient significantly correlated with its content in the plant. Relationships between soil characteristics, available nutrient in soil, and their content in plant leaves were also attempted.     

Correlations between element concentrations in spruce foliage and forest soils

Abstract

The relationships between foliage element concentrations in red spruce and soil chemical properties were studied to determine if standard soil measurements of individual elements in soils were well correlated with the concentrations of these elements in foliage. Significant positive correlations between O horizon and foliage concentrations existed only for K, Mn and P. Significant negative correlations between the concentrations of the major divalent cations (i.e. Ca, Mg, Mn) and K in the foliage were found suggesting a possible antagonism between the mono‐ and divalent cations for uptake from the soil. Trees with the highest foliage concentrations of Ca also were determined to be growing on soils which were producing the best growth rates. Foliage concentrations of P, and to a lesser extent K and Mg, were below values considered to be adequate for optimum growth in red spruce.     

A rapid method to determine cation exchange capacity and exchangeable bases in calcareous,gypsiferous, saline and sodic soils

Summary

A simple, single‐step extraction with LiEDTA for the estimation of CEC and exchangeable bases in soils has been developed. Multivalent cations are stripped from the soil adsorption sites by the strongly chelating agent EDTA, and are replaced by Li. In soils without CaCO₃ or water soluble salts, exchangeable divalent cations (Ca, Mg) are chelated by EDTA and exchangeable monovalent cations (Na, K) are replaced in a single extraction step using 0.25–2.5 g of soil and 10.0 ml of extractant.

In calcareous soils the CEC can be determined in the same way, but for the extraction of exchangeable Ca and Mg, another separate extraction is needed because dissolution of calcite by EDTA is unavoidable. This extraction is done with as much NaEDTA as needed to extract only exchangeable Ca and Mg in a 1:2 (m/V) soil/alkaline‐50% (V/V) aethanolic solution to minimize dissolution of calcite.

In gypsiferous soils gypsum is transformed into insoluble BaSO₄ and soluble CaEDTA by LiBaEDTA thus avoiding interference of Ca from dissolution of gypsum, which renders the traditional methods for determining CEC unsuitable for such soils. To determine exchangeable Ca and Mg, Na₄EDTA is used as for calcareous soils.

In saline/sodic soils replacement of Na by Li is incomplete but the Na/Li‐ratio at the complex after extraction is proportional to the molar Na/Li‐ratio in the extracts, so that the CEC and original exchangeable sodium (ESP) content can be calculated. Additional analysis of Cl and, if necessary, SO₄ in the extracts of saline soils can be used to correct for the effect of dissolution of the salts on the sum of exchangeable cations.

This new method is as convenient as the recently developed AgTU (silverthiourea), but is better suitable for calcareous and gypsiferous soils.     

Salinity induced effects on the nutrient status of soil,corn leaves and kernels

Abstract

The effect of salinity in inducing soil macro and micronutrient deficiencies that can decrease crop growth was evaluated in a corn (Zea mays L.) field located in east central Wyoming. In this study water soluble Na was found to be a better predictor of salinity than pH and other cations. Soil saturated paste extracts had electrical conductivities that were negatively correlated with soil total K, Cu, Fe, and Mn. Total N, NO₃‐N, PO₄‐P, Zn, pH, and water soluble Na, Ca, and Mg of the soil were positively correlated with EC. Significant positive relationships existed between soil EC and N, P, Mo, and Zn, and negative relationships with K, Cu, Fe, and Mn of corn leaves and kernels. Concentrations of nutrients in the kernels were positively correlated with corresponding nutrient concentrations in the leaves and with AB‐DTPA extractable soil nutrients. The analysis of variance of EC data indicated that soil samples possessing high salinity were higher in pH and contained significantly higher soluble Na, Ca and Mg, total N, N0₃‐N, PO₄‐P, and Zn and significantly lower Mn compared to samples having low salinity. The kernel weight per cob and plant height were significantly reduced as salinity increased.     

Ionic equilibria,selectivity and diffusion of cations in soil as influenced by anion additions

Abstract

An experiment was carried under controlled conditions to investigate the influence of the anions, H₂PO₄ ^‐. and Cl on the ionic equilibria, selectivity and effective diffusion of Rb, K, Na, Ca, Mg in two Indiana soils.

Additon of anions to the soils increased the concentration of cations in soil solution. In both the soils receiving H₂PO₄ ^‐, lower cation concentrations were found in the soil solution than in those receiving Cl^‐ . Additon of H₂PO₄ ^‐and Cl^‐ reduced the ion selectivity coefficient, k, for various homovalent (Rb/K, Rb/Na, K/Na, Ca/Mg) and mono‐divalent ion pairs (Rb/Ca, Rb/Mg, K/Ca, K/Mg). In Zanesville soil treatments receiving H₂PO₄ ^‐ had lower k values for mono‐divalent cations than treatments receiving Cl^‐. However, no such conclusions could be drawn for Raub soil. Soils treated with H₂PO₄ ^‐ had higher k values for homovalent cations than Cl^‐ treated soils. The differences in the selectivity of adsorption in these two soils might be attributable to the differences in the type and nature of exchange materials and cation concentrations on the exchange phase.

Addition of H₂PO₄ ^‐ or Cl^‐ enhanced the magnitude of effective diffusion coefficient. (De) of all the cations under considerations. The magnitude of effective diffusion coefficient for cations was lower for H₂PO₄ ^‐ treated soils than Cl^‐ treated soils. Such a reduction in De is related to the reduction in cation concentration in soil solution thereby increasing the buffer capacity for the ions under consideration.     

Use of the nitrate specific ion electrode in soil testing

Abstract

The construction, theory and many of the factors such as interfering anions, extracting agents, soil to solution ratio, reference electrodes, accuracy and precision of the nitrate ion selective electrode are discussed in relation to routine soil testing for nitrate nitrogen.     

On the differences of oxidizing power of paddy rice seedling roots among some varieties

Introduction

For improvement on the culture techniques of paddy rice, it is regarded most important to clear up the interactions between roots and rhizosphere soil, in addition to the studies on metabolic process such as photosynthesis and nutrients absorption etc.     

Seasonal sucrose,drymatter, and cation concentrations of sugarbeet as influenced by variety and N‐fertilization

Abstract

This study evaluated the effect of variety and nitrogen (N) fertilization on sucrose, dry‐matter, and cation concentrations in sugarbeet (Beta vulgaris L.) root tissue. A field experiment was conducted on a non‐saline, calcareous Nunn clay loam soil (Aridic argiustoll) using a factorial experimental design with three N‐rates, two varieties, and four replications. Beets were harvested nine times during the growing season. The first and final harvests were on June 25 and October 11, respectively. In addition to the above measurements, purity and extractable sucrose also were measured at the final harvest. Dry‐matter content, sucrose, sums of monovalent and divalent cations, and the monovalent:divalent cation ratios all were influenced significantly by variety, N‐fertilization, and date of harvest. Sucrose concentration was negatively correlated to the sum of monovalent and divalent cations. Root drymatter content was negatively correlated to the monovalent:divalent cation ratio. A relationship of cation concentration to the organic‐ and inorganic‐ anions that influence purity is discussed.     

Effect of cultivation on chemical characteristics and respiratory activity of crusting soil from Mazowe (Zimbabwe)

Abstract

Clearing and cultivation in crusting soils from Mazowe (Zimbabwe) has lead to severe changes in most physico‐chemical characteristics related to the concentration and distribution patterns of plant nutrients and to the total amount of soil organic matter. Nevertheless, the concentration of the different humus fractions showed lower intensity changes, as did the mineralization rates of the organic matter. The most significant effects of cultivation on the soil chemical characteristics coincided with those considered to favor clay dispersion and crusting phenomena, including generalized desaturation of the exchange complex and losses of divalent ions with a potential bridging effect between soil particles. Concerning the soil organic matter, the humic acid tended to concentrate in the cultivated soils as a probable consequence of selective biodegradation of the other humic fractions. The composition and activity of soil humus suggest low‐performance organo‐mineral interactions: in these soils the active turnover of the plant wastes is not regulated by intense physico‐chemical interactions with the soil mineral fractions, or by physical encapsulation of organic particles. In consequence, the mineralization rates were relatively constant in the soils studied and unrelated to soil organic matter concentration. The results suggests that there is a possibility to revert the early degradation stages of these soils through a rational management of suitable amounts of crop wastes.     

Microscopic observation of charred plant fragments isolated from several Ando soil samples by the specific gravity method

Abstract

Charred plant fragments were isolated from 5 Ando soil samples, containing Type A humic acids, by the specific gravity (s.g.) method using a sodium polytungstate solution as heavy solution. Microscopic observation indicated that the charred plant fragments, which are black or blackish brown, were the main components in both fractions of less than s.g. 1.6 Mg m^?3 that had been isolated before and after HCl-HF treatment of the soil samples. Furthermore, it was suggested that most of the fragments in the < 1.6 fractions isolated before the treatment originated from woody plants. On the other hand, the fragments in the < 1.6 fractions isolated after the treatment were mainly amorphous, although the shape of several fragments was similar to that of vascular tissues of woody and herbaceous plants. The sum of the organic-C contents of both < 1.6 fractions ranged from 4.08 to 47.8 g kg^? whole soil, and 3.8–32.7% of total organic-C of the whole soil originated from these fractions. No constant relationship was observed between the organic-C contents of both fractions and the morphological characteristics of the charred plant fragments.