Sorption Properties Of Soil Research Articles

Influence of liquid manure and NPK on selected sorption properties of soil

The aim of the experiment was to assess the effect of long-term fertilization with liquid manure applied annually and biennially and with mineral fertilizers on selected sorption properties of soil, i.e. the content of exchangeable magnesium, potassium, calcium, sodium and as well as the value of hydrolytic acidity, sorption capacity and base cation saturation ratio. It was found that fertilization with liquid manure, in contrast to NPK application (N as NH4NO3, P as triple super phosphate, K as KCl), led to a significant rise in the content of exchangeable magnesium in soil, whereas application of liquid manure or mineral fertilizers contributed to a significant increase in the potassium content in soil. Application of liquid manure did not cause significant changes in the value of hydrolytic acidity between the lowest and the highest dose used, while mineral fertilization contributed to an increase in the value of hydrolytic acidity. Application of liquid manure reduced the value of hydrolytic acidity as deep as the third layer of the soil profile. Fertilization with liquid manure and mineral fertilizers did not affect the content of exchangeable calcium in the whole soil profile, although the calcium content in the soil profile increased to the 51-75 cm layer. Application of liquid manure and NPK did not alter significantly the content of exchangeable sodium in soil. Upon application of both liquid manure and NPK, no significant changes were observed in the total base exchangeable cations in soil (S) or in the sorption complex saturation (V). However, S and V significantly increased along the depth of sampling. It was found that fertilization with both liquid manure and mineral fertilizers did not induce substantial changes in the soil sorption capacity, although there was an increase in the total sorption capacity in two layers (51-75 cm and 76-100 cm) of the soil profile.

Diffusion experiments for estimating radiocesium and radiostrontium sorption in unsaturated soils from Spain: Comparison with batch sorption data

As sorption data obtained from batch tests are often used to estimate pollutant transport in unsaturated soils, comparison between sorption data obtained in the two conditions is required to ensure a correct risk assessment. With this aim, radiostrontium and radiocesium apparent diffusion coefficients ( D a) were quantified in nine unsaturated soils, and the derived distribution coefficients ( K d) were compared with K d data from batch experiments. The D a(Sr) and the D a(Cs) ranged from 1.8 × 10 −11 to 1.5 × 10 −10 m 2 s −1, and from 1.0 × 10 −13 to 5.9 × 10 −11 m 2 s −1, respectively. The D a(Sr) varied according to both soil packing parameters and properties governing Sr interaction. For Cs, the soil sorption properties explained the variation on D a(Cs). The K d values derived from D a (from 0.014 to 1.8 L kg −1 for Sr; from 0.55 to 942 L kg −1 for Cs) were lower than from batch tests (from 1 to 97 L kg −1 for Sr; from 10 to 14,600 L kg −1 for Cs), thus indicating that batch data may not accurately describe radionuclide transport in unsaturated soils. However, the two sets of data correlated well, thus suggesting that radionuclide transport can be estimated from batch tests, which are faster than diffusion experiments.

A Comparative Study of Phosphate Sorption in Lowland Soils under Oxic and Anoxic Conditions

Phosphate (P(i)) release due to Fe(III) oxide dissolution is well documented for soils undergoing reduction. The P(i) sorption properties of soils in anoxic conditions are, however, still under consideration. In this investigation, P(i) sorption to strictly anoxic soils was compared with oxic conditions to assess the potential of lowland soils to function as traps for P(i) when flooded with drainage water. Batch sorption experiments were performed on seven minerogenic soils. Sorption to the anoxic soils was conducted after anoxic incubation, resulting in reduction of 36 to 93% of the dithionite-extractable Fe(III) (Fe(BD)). Langmuir fitted P(i) sorption isotherms showed a P(i) release of up to 1.1 mmol kg(-1) in six soils when P(i) concentrations in the matrix (P(sol)) were lower than 10 microM. Phosphate desorption was attributed to dissolution of amorphous iron oxides, and higher pH under anoxic conditions. The point of zero net sorption (EPC(0)) increased 2- to 10-fold on reduction. Five soils showed higher P(i) sorption capacities in the anoxic than in the oxic state at higher P(sol) concentrations. Solubility calculations indicated that precipitation of vivianite or similar Fe(II) phosphates may have caused the higher sorption capacities. Use of maximum sorption capacity (S(max)) is therefore misleading as a measure of P(i) sorption at low P(sol) concentrations. The results demonstrate that none of the strongly anoxic soils, irrespective of the initial Fe(III) oxide content, the P saturation, and the degree of Fe(III) oxide reduction, could retain P(i) at natural P(sol) concentrations in agricultural drainage water.

Quantification of vanadium adsorption by German soils

Vanadium adsorption by soils representing different soil types from Germany has been studied. For 30 soils ‘Freundlich’ type sorption isotherms have been deduced from laboratory vanadium(V) adsorption experiments. The native adsorbed vanadium quantity of a soil ( S 0) and the Freundlich parameters m and log k have been determined by non linear regression of the experimental data to the Freundlich model. Pronounced differences in vanadium adsorption of different soils exist and could be quantified. The vanadium adsorption data could be generalized by grouping the soils into four classes according to their vanadium adsorption properties. For each class (sandy soils, top soils, sub soils with pH < 5.5, and sub soils with pH > 5.5) mean Freundlich parameters m and log k have been calculated to be 0.59, 0.72, 0.52, 0.57 and 2.55, 2.89, 4.29, 3.41, respectively. These parameters can be used to estimate vanadium sorption properties of soils for which no vanadium sorption experiments are available. Aqua regia soluble vanadium contents of the studied soils (range 1.7–143 mg/kg; median 32 mg/kg) and leached vanadium concentrations from experiments without vanadium addition (range 0.08–37 µg/l; median 2.1 µg/l) are also given.

Biologically active secondary metabolites in white clover (Trifolium repens L.) – a review focusing on contents in the plant, plant–pest interactions and transformation

To exploit biologically active compounds from white clover (Trifolium repens L.) for suppressing weeds and soil-borne diseases, either as isolated products (biopesticides) or through cultivars with enhanced production of these compounds, the biologically active compounds must be identified, plant content measured, and their fate in soil known. The present review summarizes the published knowledge needed for such exploitation; providing essential information on structure and concentration of flavonols, flavones, condensed tannins, isoflavones, isoflavanones, pterocarpans, coumestans, cyanogenic glucosides, and saponins in healthy and stressed white clover plants. Various stresses and particular cultivars affect the concentrations of several of the compounds. Information on biological effects and the degradation/transformation of these compounds in plants or by microorganisms is available. There is no information on the degradation pathway in soil, the mechanisms of exudation and leaching of compounds from plants, and soil sorption properties of the compounds. The clover soil fatigue problem is increasing in grasslands and causes problems especially in organic farming. Research efforts focused on biological elements of clover soil fatigue have not explained it, and the influence of secondary metabolites has not been investigated. There are few investigations into the interaction between beneficial fungi/fungal-diseases and the occurrence of biologically active secondary metabolites in white clover plants. Such studies are critical to better understand beneficial fungi and pathogens.

A contribution to the effect of liming on forest soils: review of literature

Extensive forest areas were ameliorated by large-scale liming in the last years in order to prevent proceeding acidification and degradation of forest soils. The hitherto knowledge of liming effects on the function of forest soils still appears insufficient for an unambiguous evaluation. Sorption properties of soils and acidity are favourably affected by liming and the favourable effect is usually manifested in the layer of forest floor humus and in mineral soil within ten years. Reduction of soil acidity stimulates development of a bacterial component of microflora, soil edaphon, and good prerequisites are formed for a release of nutrients from soil organic matter. Improvement of some physical parameters of soils and negative effect of liming on the depth of rooting in spruce, availability of nutrients at some sites and in connection with mechanical soil preparation were also described. A key point of liming effect on forest soils is nitrogen dynamics. Mineralization of nitrogen is stimulated at nitrogen-rich sites with C/N &amp;lt; 30. Nitrogen-limited sites show nitrogen mineralization inhibited by liming with signs of pronounced deficiency in spruce nutrition. A positive effect of liming on nutrition with bases is generally accompanied by an adverse influence on N dynamics in acidic soils under spruce monocultures. Therefore it is possible to state that liming induces relatively marked changes in the soil but the actual growth response of woody species cannot be derived only from these changes.

Effectiveness of Agricultural Practices in Decreasing Radionuclide Transfer to Plants in Natural Meadows

Agricultural practices (discing+ploughing, reseeding, liming and the use of NPK fertilisers) were used to decrease 137Cs (RCs) and 90Sr (RSr) transfer to plants in natural meadows in Russia, Belarus and Ukraine. Experiments were carried out in the 1997-1999 period. Results from field experiments showed that RCs transfer in control meadows was in most cases higher than in ploughed plots (up to 3-4 times). Discing+ploughing was the most effective treatment. In addition, there was a significant trend in decreasing RCs transfer when using increasing amounts of NPK fertiliser. A time dependence was noticed, since the overall transfer was lower in the following years after the start of the experiments. Regarding RSr, no significant effect was observed in the first year. However, the effect of ploughing caused a transfer decrease by 2-4 times in the second year. Laboratory experiments showed that changes in RCs soil sorption properties are likely after ploughing, and that NPK fertilisation and liming rates used were not sufficient to ensure K and Ca+Mg concentrations in soil solution high enough to achieve the maximum decrease in radionuclide transfer.

Changes in some soil phosphorus availability parameters as induced by phosphorus addition and soil sorption properties

Changes in agronomic and environmental soil phosphorus (P) availability parameters, i.e., Mehlich‐ and Olsen‐extractable P, reversibly‐adsorbed P, soil‐solution P, and equilibrium‐P concentration were determined following equilibration of 13 Italian soils with five rates of P application (0, 12.5, 25, 50, and 100 mg P kg‐1 soil). Soil P availability as determined by each parameter increased with added P. The relative change in soil P availability with added P was a function of soil sorption index silicon (SI), according to the equation DP=(Padded)a*exp(b+g*SI). This equation accounted for 94 to 98% of the variance in soil‐P availability. The inclusion of SI in a soil testing program may increase the reliability in assessing both soil‐P fertilizer requirements and the vulnerability of a soil to P loss in runoff following land application of fertilizer or manure P.

Description of Atrazine Transport in Soil with Heterogeneous Nonequilibrium Sorption

AbstractNumerous studies have shown that a single sorption rate constant is insufficient to describe nonequilibrium sorption and transport of organic solutes in soil. To investigate the effect of sorption rate (or, more generally, sorption site) heterogeneity on solute transport, we proposed a model assuming a γ distribution for both sorption rate and partitioning coefficient (abbreviated as GS for gamma‐distributed sites). The model was tested by a series of column leaching and batch sorption experiments conducted with atrazine (2‐chloro‐4‐ethylamino‐6‐isopropylamino‐s‐triazine) over various time scales. Observed asymmetry and a left‐hand shift of measured breakthrough curves (BTCs) with increasing flow velocity (0.51 to 21.3 cm/h) or decreasing column length (15.5 to 6.0 cm) were successfully predicted by GS with sorption parameters obtained from an independent experiment. However, two other distinct sorption site models, the two‐site first‐order sorption (TSFO) and the two‐site spherical diffusion (TSSD), were not able to describe the observed BTCs unless parameter values were adjusted for each case. In batch sorption experiments, increasing equilibration time (ranging from 1 to 237 h) was found to generally increase the isotherm‐derived partitioning coefficient (KD). The increasing trend was independently well‐predicted using the GS model with optimized parameters from the column studies. The TSSD was less successful and TSFO the least able to reconcile the entire range of change in KD. The weak time‐scale dependency of GS found in both column and batch experiments supports the assumption that a wide range of heterogeneous sorption sites or domains have been involved in the overall sorption process but to a variable degree as time elapsed. Potential alteration of soil sorption properties by γ irradiation was also observed.

SULFATE RETENTION AND RELEASE IN SOILS AT PANOLA MOUNTAIN, GEORGIA

Inorganic sulfate pools, sulfate sorption characteristics, and Fe and Al fractions were determined on soils at Panola Mountain, a 41-ha forested watershed in the Georgia piedmont. Sulfate adsorption was measured in batch solutions that bracketed the range of ambient sulfate concentrations and soil solution acidity. The slope and intercept of the initial mass (IM) isotherms, formed from plots of sulfate retained against sulfate added, were used to compare sorption behavior among soils. The reversibility of sulfate adsorption was determined by measuring desorption of soluble sulfate from soil before and after equilibration with a concentrated sulfate solution. Sulfate sorption properties of soils at Panola Mountain fall along a continuum between two end members. The “low-adsorbing” end member comprises shallow soils (0–10 cm), with high water-soluble sulfate (Sw), low phosphate-extractable sulfate (Sp-w), high organic matter, low sulfate retention ability (IM isotherm slope near 0.0), and high sulfate adsorption reversibility. The “high-adsorbing” end member comprises deeper soils (>10 cm), with higher total native sulfate (mostly as Sp-w), low organic matter, high sulfate retention ability (isotherm slope near 1.0), and low sulfate adsorption reversibility. Sulfate retention was only weakly related to Fe and Al fractions, possibly because of inhibition of adsorption by organic matter. Sulfate concentrations in surface waters reflect the spatial distribution of soil sulfate retention properties; baseflow, representing water which has equilibrated with the mineral subsoil, has sulfate concentrations near 10 μeq/L, whereas stormflow, which is dominated by water flowing through shallow horizons, has sulfate concentrations near 100 μeq/L.

On the prediction of soil sorption coefficients of organic pollutants from molecular structure: application of molecular topology model

This study was undertaken to test the ability of the molecular connectivity model to predict the soil sorption coefficients of polycyclic aromatic hydrocarbons (PAHs), alkylbenzenes, chlorobenzenes, chlorinated alkanes and alkenes, heterocyclic and substituted PAHs, and halogenated phenols. Tests performed on 31 such compounds clearly demonstrate that this simple nonempirical model accurately predicts the soil sorption coefficients for the above classes of compounds. Moreover, the model out performs the traditional empirical models based on 1-octanol/water partition coefficients or water solubilities in accuracy, speed, and range of applicability. Additional tests on approximately 160 polar and ionic compounds show that the above topological model plus a single semiempirical variable is capable of accounting for the soil sorption properties of nearly 95% of all organic chemicals whose soil sorption coefficients have been measured. The results of these tests demonstrate that the molecular connectivity model is a very accurate predictive tool for the soil sorption coefficients of a wide range of organic chemicals and that it can be confidently used to rank potentially hazardous chemicals and thus to create a priority testing list. 55 references, 5 figures, 7 tables.

Sulphate nutrition, movement, and sorption, with special reference to a gley podzol, west coast, south island

Abstract Using S35, rapid lateral movement of applied sulphate was shown to occur on agley podzol, suggesting little capacity to retain sulphate and heavy losses of this anion in drainage water. Field trials confirmed these findings. Gypsum applied to the soil surface protected white clover against sulphur deficiency for a relatively short time only. The action of flowers of sulphur, however, proved both rapid and persistent. A relatively quick method of determining sulphate sorption properties of soils in the laboratory is described. This method promises to predict the propensity of soils to lose sulphate by leaching provided soil physical and climatic factors receive proper consideration.