bluuebunny/crossref_metadata_2025_split huggingface dataset:
THE USE OF POLYACRYLAMIDE TO REPLACE CARBON IN THE DETERMINATION OF‘OLSEN'S’EXTRACTABLE PHOSPHATE IN SOIL
Authors: BANDERIS A. , BARTER D. H. , HENDERSON K. 
Published: July 2006

SummaryThe addition of 2.5 mg/l of polyacrylamide to 0.5M NaHCO3 used as an extractant for ‘available’ phosphate overcame most of the analytical difficulties associated with the use of activated carbon which was recommended in the original procedure of Olsen et al. (1954). No significant differences in the amount of P extracted were found between polyacrylamide and carbon and with the former, technical problems were greatly reduced. Consequently, the modification of the original method to incorporate polyacrylamide has been adopted in the Agricultural Development and Advisory Service of the Ministry of Agriculture, Fisheries, and Food as a standard method for the determination of available phosphate in soils.
THE ACCUMULATION OF SOIL ORGANIC MATTER AND ITS CARBON ISOTOPE CONTENT IN A CHRONOSEQUENCE OF SOILS DEVELOPED ON AEOLIAN SAND IN NEW ZEALAND
Authors: GOH K. M. , RAFTER T. A. , STOUT J. D. , WALKER T. W. 
Published: July 2006

SummarySoil organic matter was extracted by a mixture of O.IM Na4P2O: O.IM NaOH from a chronosequence of weakly weathered soils developed on aeolian sand, and fractionated into humin (non‐extractable), humic acid, and fulvic acid. The mass of total organic carbon in the profiles, the 14C content and the 13C/12C ratios were also determined.The weight of total carbon increased rapidly at first and then gradually without attaining a steady state. This trend was also shown by the humin and fulvic acid fractions, but the humic acid fraction appeared to have reached a maximum after about 3000 years. The order of total weights of the organic fractions was humin > fulvic acid > humic acid.The evidence suggests that the proportions of the humic fractions formed by decomposition are related to soil differences but not to vegetation. The greater part of the plant material found in the soils appears in the humin and fulvic acid fractions.
IRON AND ALUMINIUM AS CEMENTING SUBSTANCES OF SOIL AGGREGATES
Authors: GIOVANNINI G. , SZQUI P. 
Published: July 2006

SummaryA method is described for extracting fractions of soil iron and aluminium without removing organic matter. The extraction is by acetylacetone in a non–polar solvent and is virtually complete in zoo h.Similar amounts of iron and aluminium are extracted by acetylacetone in either benzene or water, but organic matter is extracted in detectable amounts only by acetylacetone in water. Extraction in aqueous solution after acetylacetone in benzene removes only organic matter, with no appreciable release of iron and aluminium. Metals extracted by acetylacetone in benzene are therefore considered to be bonded to that part of the organic matter which is extracted by acetylacetone. Water alone does not extract significant amounts of organic matter after removal of iron and aluminium by acetylacetone in benzene. The refolding of the hydrophilic surface units of the organic matter, caused by non–polar solvents, may hinder the extraction by water.
ADSORPTION OF ALIPHATIC ALCOHOLS BY SOIL MINERALS AS A METHOD OF EVALUATING THEIR HYDROPHOBIC SITES
Authors: TSCHAPEK M. , WASOWSKI C. 
Published: July 2006

SummaryThe density of hydrophobic sites on the surface of some soil minerals has been determined by adsorption of aliphatic alcohols from aqueous solution. The amount of alcohol adsorbed was evaluated by measurements of the surface tension of the solution.
DECODE—A COMPUTER PROGRAM FOR TRANSLATING CODED SOIL PROFILE DESCRIPTIONS INTO TEXT
Authors: WEBSTER R. , LESSELLS CHRISTINE M. , HODGSON J. M. 
Published: July 2006

SummaryA computer program has been written in Fortran to translate coded soil profile data into conventional text. It reads data from 80‐column punched cards in fixed format. The data can be screened for their relevance to an inquiry, and the output can be adapted to the user's requirements. Standard codes, data specifications, and output layout are provided, but users who have special requirements can provide their own. One version of the program provides a more or less abbreviated translation with a tabular layout, the other gives complete descriptions in conventional text with punctuation.
SOIL NITROGEN
Authors: GASSER J. K. R. , KALEMBASAZ S. J. 
Published: July 2006

SummarySoils from experiments receiving various treatments in the field were used to investigate the effects of different amounts and forms of organic matter in a clay and a sandy soil on the inter‐correlations between several laboratory methods of measuring available‐N. The correlations between some of these measurements, and the growth and N uptake of ryegrass grown in the glasshouse with and without added fertilizer‐N were also investigated.Seven clay soils and eight sandy soils were used, containing different amounts of organic matter of different kinds, as a result of various field treatments. For the sandy soils, one sample was taken from each plot of the experiment which allowed the effects of field variations on the values determined in the laboratory to be measured.The correlations between methods of measuring available‐N showed that measurements obtained by aerobic incubation, anaerobic incubation, and nitrogen extracted by boiling water, correlated best with one another. These measurements also correlated best with the performance of ryegrass in the glasshouse.N uptake by ryegrass from soils without fertilizer‐N always correlated better with measurements of available‐N than did dry matter produced. With added fertilizer‐N, dry matter correlated better with available‐N than did N uptake at the first cut but worse for the total of three cuts. Fertilizer‐N recovered in the grass at the first cut was significantly and negatively correlated with available‐N.Values of available‐N from the individual samples of the sandy soil showed that those for aerobic incubation had the largest standard error and had the greatest range expressed as a per cent of the mean value, and those for nitrogen extracted by boiling water least error and range. All methods correlated similarly with the performance of ryegrass in the glasshouse. All three methods successfully identified the treatments giving most available‐N.
EFFECTS OF SOLUTION: SOIL RATIO ON PHOSPHATE SORPTION BY SOILS
Authors: HOPE G. D. , SYERS J. K. 
Published: July 2006

SummaryIsotherms for the sorption of inorganic phosphate (P) by three contrasting soils during 40 h showed a dependence on solution: soil ratio. Above a final solution P concentration of 0.5 μg ml−1, more P was sorbed at a solution: soil ratio of 5:1 than at 40:1 for a given level of P in solution. With time up to 146 h, the effect of solution: soil ratio on P sorption was kinetically controlled.Equilibrium solution P concentrations, estimated by extrapolation of the linear relationships between solution P concentration and the reciprocal of time to I/t= o (i.e. t=∞)appeared to be coincident for each solution:soil ratio at high and the low levels of added P. Consequently, sorption isotherms at equilibrium would be coincident, irrespective of the solution soil ratio used.The kinetic control of solution: soil ratio on P sorption is interpreted in terms of the number of P sorbing sites and initial solution P concentration on the rate of P sorption by soils.
THE IDENTIFICATION AND DETERMINATION OF GLUCURONIC AND GALACTURONIC ACIDS IN SCOTTISH SOILS AND SOIL FRACTIONS USING ION‐EXCHANGE AND GAS‐LIQUID CHROMATOGRAPHY
Authors: MUNDIE C. M. 
Published: July 2006

SummaryTwo methods have been used for the identification and determination of uronic acids in soils and soil fractions. The uronic acids were released by hydrolysis with sulphuric acid. After partial purification by ion‐exchange chromatography they were separated either by further ion‐exchange or by gas‐liquid chromatography of derivatives. The latter method is preferable for determination of the specific activities of uronic acids in soil tracer work. Both galacturonic and glucuronic acids were detected in the four Scottish soils examined, the galacturonic acid being present in slightly greater amounts in each soil. Mannuronic acid was not detected. The total amount of uronic acids found ranged from about 4 mg to 6 mg/g soil.
A TOPOSEQUENCE OF ALPINE SOILS ON CALCAREOUS MICASCHISTS, NORTHERN ADULA REGION, SWITZERLAND
Authors: BUURMAN P. , VAN DER PLAS L. , SLAGER S. 
Published: July 2006

SummaryOn calcareous micaschists in the northern Adula Region, Switzerland, brown soils are formed under grasses and herbs at altitudes below 2000 m. Podzols occur below Ericaceae below 2000 m and are formed irrespective of vegetation above this altitude. Calcimorphic soils are not found.Brown soils have a stable clay mineral association of chlorite and mica, while in the A horizons of podzols and in initial podzols alteration of chlorites to smectites occurs.
A COMPARISON OF FIELD ESTIMATES AND LABORATORY ANALYSES OF THE SILT AND CLAY CONTENTS OF SOME WEST MIDLAND SOILS
Authors: HODGSON J. M. , HOLLIS J. M. , JONES R. J. A. , PALMER R. C. 
Published: July 2006

SummaryField estimates of silt and clay contents were compared statistically with the silt (2‐60 μm) and clay (<2 μm) contents determined by the pipette method of 184 soil horizons from a large range of west Midland soils (clay contents 1–81 per cent and silt contents 3–71 per cent). Regression equations were calculated (a) for each of four surveyors using combined topsoil and subsoil data and (b) for surface and subsoils separately using combined data for the four surveyors. There is slight evidence of ‘operator bias’ and a tendency for all four surveyors to underestimate clay in surface horizons though these conclusions have limited significance because of the small number and the distribution of some of the sample populations. Single equations for the combined data from all operators and all horizons explained 75.5 per cent of the variation in field estimates of silt content and 85.4 per cent of the variation of clay estimates. For silt, the regression line almost passes through the origin with a slope not significantly different from unity, whilst for clay, the line intercepts the y‐axis close to zero and has a slope of 0.904. The results show that, with experience and adequate reference samples, surveyors can confidently estimate the particle‐size distribution of a wide range of soils. These studies were done during soil mapping in Staffordshire, Hereford and Worcester, and Salop using the newly introduced soil classification (Avery, 1973) and revised Handbook (Hodgson, 1974) of the Soil Survey of England and Wales.
VARIABILITY IN THREE AREAS OF THE DENCHWORTH SOIL MAP UNIT
Authors: BANFIELD C. F. , BASCOMB C. L. 
Published: July 2006

SummaryThis paper shows correlations between soil properties and uses multivariate techniques to investigate similarities between profiles in relation to substrata. It compares laboratory measurements and field observations as means of characterizing soils.Correlations between two pH measurements and between fine clay and clay are large at all depths. Linear regressions indicate that close prediction of pH in water and fine clay content is possible from pH in CaCl2, and clay content respectively. Prediction of organic matter content from matrix Munsell colour value seems reliable within this limited range of soils. Field observation of carbonates correlates well with the laboratory measurement. Some indication of iron oxide content is given by matrix chroma.Significance of observed horizonation is confirmed by two minimum spanning trees, based on field observations and on laboratory measurements, which each link the samples in a similar way. Mean similarities between depths show that depths 2 and 3 are most alike.Inclusion of profiles on three different geological substrata under one series name is justified by the within‐ and between‐substrata similarities being alike, although profiles from each are not mixed at random.Plots of the profiles relative to the axes obtained by principal coordinates analysis of laboratory measurements and field observations show remarkable agreement. Rotational fitting of these plots indicates little difference between the three substrata.
THE ADSORPTION OF POLYVINYL ALCOHOL ON GIBBSITE AND GOETHITE
Authors: KAVANAGH B. V. , POSNER A. M. , QUIRK J. P. 
Published: July 2006

SummaryThe neutral polymer, polyvinyl alcohol, has been shown to be adsorbed by the hydrated oxides gibbsite and goethite. A reduction in adsorption on gibbsite is observed when it is dried prior to the adsorption measurements. Evidence from electron microscopy suggests that this is caused by a reduction in the accessible surface area due to aggregate formation, rather than a change in the surface properties of the substrate. Changes in either the pH or the ionic strength of the medium do not significantly alter the amount of PVA adsorbed. Electrophoretic data indicate that the thickness of the adsorbed layer on both clays and oxides is in excess of 10 nm at high concentrations of polymer.
THE USE OF CATHODOLUMINESCENCE IN THE IDENTIFICATION OF SOIL MINERALS
Authors: DUDLEY R. J. 
Published: July 2006

SummaryAn apparatus, based on an optical microscope system, has been constructed for the subjective observation of cathodoluminescence, and the value of the technique has been determined for the examination of minerals and soils. The use of cathodoluminescence for the specific identification of minerals was found to be limited by the observation of different luminescent colours from the same minerals, and the same luminescent colour from different minerals. However, a sufficient variety of luminescent colours is believed to exist to allow the method to be used in conjunction with others for the identification of mineral grains. An examination of the trace element levels in a small group of mineral separates was found to be uninformative in trying to explain the variations in luminescent colours found.
RAINDROP IMPACT STRESS AND THE BREAKDOWN OF SOIL CRUMBS
Authors: GHADIRI H. , PAYNE D. 
Published: July 2006

SummaryThe stress produced by raindrop impact, calculated as the rate of change of momentum divided by area of contact, was found to be only partly satisfactory in studies of breakdown of paper tissue and soil crumbs. The calculated stresses for failure did not agree closely with values found by other methods, and varied systematically with raindrop size. The differences were related to the effect of duration of application of stress, and to the concentration of stress around the periphery of the drop.
ADSORPTION, DESORPTION AND SOLUBILITY RELATIONSHIPS OF LEAD AND CADMIUM IN SOME ALKALINE SOILS
Authors: SINGH BIJAY , SEKHON G. S. 
Published: July 2006

SummaryIn some alkaline soils of Punjab (India) the adsorption, desorption and solubility relationships of lead and cadmium were investigated and the results analysed by the Langmuir equation.Both the metals are retained in soils by adsorption on mineral interfaces and interaction with organic matter and calcium carbonate. At high concentrations, these probably precipitate as hydroxides. Sequential desorption of Pb and Cd with 1 MKCI and 0.05 MCu(CH3COO)2 provided a measure of their exchangeable and chelated form.
ADSORPTION ON HYDROUS OXIDES. III. FULVIC ACID AND HUMIC ACID ON GOETHITE, GIBBSITE AND IMOGOLITE
Authors: PARFITT R. L. , FRASER A. R. , FARMER V. C. 
Published: July 2006

SummaryAdsorption isotherms were obtained for fulvic and humic acids on synthetic gibbsite and goethite and on a natural imogolite. The results were interpreted with the help of spectra of the adsorption complexes, and measurements of hydroxyl displaced. The mechanism of adsorption involved ligand exchange with the surface hydroxyl groups and hydrogen bonding. The hydroxyl groups displaced included singly coordinated species on the (100) face of goethite and on the edge faces of gibbsite. The doubly coordinated hydroxyl groups on the (001) face of gibbsite were not replaced, and this face adsorbed only un‐ionized fulvic acid probably by a hydrogen bonding mechanism. Imogolite adsorbed most fulvic acid because of its high porosity. Only isolated places on its surface reacted with fulvic acid to form carboxylate groups.
ADSORPTION OF PHOSPHATE BY VARIOUS OXIDES: THEORETICAL TREATMENT OF THE ADSORPTION ENVELOPE
Authors: CABRERA F. , MADRID L. , DE ARAMBARRI P. 
Published: July 2006

SummaryAn explanation is put forward for the shape of adsorption envelopes found for phosphate adsorption by various metallic oxides. The equation xm= C1 (μH3PO4+μ∑anions) is proposed, where μH3pO4 is the chemical potential of undissociated H3PO4; μ∑anions is the chemical potential of all phosphate anions considered as one. component; C1 is a constant that includes influences of surface charge, chemical affinity of the metal for phosphate, specific surface area, etc., and xmis the calculated Langmuir maximum adsorption of P at each pH. The dependence of C1 on the metal present in the oxide is shown.
EFFECTS OF TILLAGE AND DIRECT DRILLING ON SOIL TEMPERATURE IN WINTER
Authors: HAY R. K. M. 
Published: July 2006

SummaryContinuous records of soil temperature were collected at 1 cm and 5 cm depth during two winters (1972–4) in cultivated and uncultivated (direct drilling) soil. When solar radiation levels were low, the observed large and irregular fluctuations in soil surface temperature appeared to be associated with advective heat flow. The stubble mulch on the uncultivated soil insulated the surface layers from temperature variation, resulting in less soil freezing than cultivated soil and fewer hours above 5° C. Some implications of these findings for cultivations for cereals are discussed.
THE FRICTIONAL CHARACTERISTICS OF STEEL SLIDING ON SOIL
Authors: STAFFORD J. V. , TANNER D. W. 
Published: July 2006

SummaryThe frictional behaviour of soil‐steel interfaces has been investigated under controlled conditions in the laboratory. The description of the behaviour by a Coulomb‐type expression has been verified in the normal stress range 10–280 kPa. However the effect of normal stress on density and hence on adhesion must be considered. Soil moisture content can change interface friction by up to 50%, the effect increasing as sliding speed is reduced. These effects have been explained by considering inter‐particle cohesion.
A SIMPLE COMPUTER MODEL FOR LEACHING IN STRUCTURED SOILS
Authors: ADDISCOTT T. M. 
Published: July 2006

SummaryA layer model for the movement of solutes in soil has been developed in which, as a working approximation, the soil solution is partitioned into mobile and retained phases. Only the mobile solution is displaced during water movement, and equilibrium is assumed to be established between the mobile and retained phases when flow ceases, giving holdback of solute. The model permits the displacement of the mobile solution through an indefinite number of layers when large amounts of rain fall. It can be assumed either that water and solute are stored in the bottom layer and can be withdrawn up the profile by evaporation or that they drain from the bottom layer. Predicted soil nitrate concentrations agreed reasonably well with those measured in a field experiment and indicated some sensitivity to layer thickness. The capacity of the model to predict concentrations in drainage is demonstrated.
CHEMICAL AND INFRARED SPECTROSCOPIC STUDIES OF FULVIC ACID FRACTIONS FROM A PODZOL
Authors: ANDERSON H. A. , FRASER A. R. , HEPBURN A. , RUSSELL J. D. 
Published: July 2006

SummaryInfrared spectroscopy and chemical degradation indicated several fulvic acid fractions from an iron‐humus podzol capable of complexing and translocating metals. Acidic polysaccharides, some of them resembling pectic acid, were isolated in appreciable quantities. These are able to bind metals through carboxyl groups, but peptide components present in the polysaccharide fraction may provide alternative metal complexing centres. The high yield of acid‐extractable organic matter from the illuvial humus, together with its high content of carboxylic acid groups, make it likely that this fraction plays a major role in the translocation of metals. Phenolic compounds allegedly associated with this process were present in the fulvic acid solution in low amounts, and only in the extracts from the organic horizons.
FACTORS INFLUENCING THE RELEASE OF COPPER AND ZINC ADDITIVES FROM GRANULATED SUPERPHOSPHATE
Authors: GILKES R. J. 
Published: July 2006

SummaryWhen copper sulphate and zinc oxide are granulated with ordinary superphosphate, insoluble copper phosphate and soluble zinc phosphate are formed. The copper phosphate has the approximate chemical composition NaCu6 H3 (PO4)5 Cl. 6H2O and a structure similar to that of the mineral sampleite. When such fertilisers are applied to soils the development of an acid phosphate solution within granules dissolves most zinc and some copper. Subsequently, diffusion and leaching release zinc and copper from within the granules.
VARIABILITY IN THREE AREAS OF THE DENCHWORTH SOIL MAP UNIT. III. SOIL GROUPING BASED ON CHEMICAL COMPOSITION
Authors: WILLIAMS C. , RAYNER J. H. 
Published: July 2006

SummaryData from a chemical determination of 21 elements plus seven Soil Survey routine laboratory measurements for three horizons of 30 soil profiles have been treated by multivariate techniques to find relationships and grouping of soil properties in soils mapped as Denchworth series.The samples profiles were developed in parent materials of Oxford, Kimmeridge and Gault clay origin. The Oxford clay grouping was confirmed, but the Kimmeridge and Gault clay soils were better represented by three rather than two classes.
A REVIEW OF THE EFFECTS OF PESTICIDES ON MICROBIAL ACTIVITY IN SOILS
Authors: WAINWRIGHT M. 
Published: July 2006

SummaryThe paper reviews the recently published literature (mainly since 1970) on the effects of pesticides on the major biogeochemical cycles in soils, including transformations of carbon, nitrogen, phosphorus sulphur, trace elements and soil enzymes.The main conclusion is that pesticides, with the exception of fumigants and some broad spectrum fungicides, have little deleterious influence on soil processes when applied at field rates.Obvious gaps in our knowledge of pesticide‐soil interactions are pointed out and suggestions are made where future research is needed.In the absence of effective biological control methods, the extensive use of pesticides in agriculture will continue. It is essential that the effects of these compounds on biochemical transformations in soils be determined, so that we can arrive at a balanced view of their effects on soil fertility.
CHLORIDE LEACHING IN THE ROTHAMSTED DRAIN GAUGES: INFLUENCE OF RAINFALL PATTERN AND SOIL STRUCTURE
Authors: ADDISCOTT T. M. , ROSE D. A. , BOLTON J. 
Published: July 2006

SummaryCalcium chloride giving 253 kgClha−1 was applied to the 20‐inch and 40‐inch 1/1000 th acre drain gauges after drainage re‐started in 1974. It was tagged with 30Cl in the 40‐inch gauge. After two preliminary peaks in each gauge, chloride concentration was related to cumulative drainage in the 20‐inch gauge with an overall pattern of peak, decline and tail, interrupted by subsidiary peaks, whereas in the 40‐inch gauge it declined very slowly with marked fluctuations. Total chloride and 30Cl behaved similarly. A simple computer model simulated the main features of the relationship well for the 20‐inch gauge, but less satisfactorily in the 40‐inch gauge and only if water was assumed to move in a very small proportion of the clay in the lower half of the gauge. These simulations and some for model rainfall regimes suggested that the shapes of the relationships were greatly influenced by rainfall pattern and by retention of soil solution in fine pores during movement in larger pores. Possible effects of soil structure on leaching are discussed.