Increase In Exchange Capacity Research Articles

Aumento na capacidade de troca de cátions em rochas biotitas ricas em Mg ou Fe pela ação da rizosfera do milho

ABSTRACT The weathering of some silicate minerals in crushed rocks may occur in a few days of cropping and generate different physicochemical properties, with potential benefits to tropical soils. This study aimed to investigate the infuence of maize (Zea mays L.) rhizosphere on the weathering products and on the cation exchange capacity of Mg-biotite from biotite schist and Fe-biotite from biotite syenite. An experiment was carried out in pots, so that plants and crushed rock materials could be evaluated during seven successive growth cycles. The nutrients iron and potassium were taken up from biotite schist and biotite syenite during cropping. The weathering of both biotites promoted by the rhizosphere caused mineralogical changes. The most expressive change in the X-ray diffraction patterns occurred in the < 53 µm particle size fraction; however, the 53-300 µm fractions also changed. The alteration in the Mg-biotite, which has a lower Fe/Mg relation in octahedral sites than the Fe-biotite, was responsible for the most expressive cation exchange capacity increase in the fractions < 300 µm. However, the Fe-biotite weathering process, which presents a higher Fe/Mg relation in octahedral sites, did not increase the cation exchange capacity.

Utilizing eco-friendly kaolinite-biochar composite adsorbent for removal of ivermectin in aqueous media

Several emerging contaminants are currently used in an unregulated manner worldwide, resulting in their increasing stringent limits in water by regulatory bodies. Thus, more viable and cheap treatment technologies are required. Recently, synergistic combinations of low-cost adsorbents have shown huge potential for aqueous toxic metals adsorption in water treatment processes. However, there is dearth of data on their potential for emerging contaminant removal. Here, low-cost kaolinite (KAC) clay was synergistically combined with blended Carica papaya or pine cone seeds, and calcined to obtain composites of KAC-Carica papaya seeds (KPA) and KAC-pine cone seeds (KPC). These adsorbents were characterized and evaluated for ivermectin adsorption at varying operating times (15–1440 min), pH (3–11), concentration (100–600 μg/L), and temperature (19.5–39.5 °C), as well as testing adsorbents’ reusability. The composites exhibited marked property differences including over 250% cation exchange capacity increases and ≥50% surface area decreases, but unchanged KAC clay primary lattice structure. Ivermectin adsorption data were explained using kinetics and adsorption isotherm models. The rate of adsorption on KAC decreased over time, while rates for KPA and KPC increased until equilibrium at 180 min; the presence of biomaterials in the composites conferred better ivermectin adsorption and retention under continuous agitation. The adsorbents exhibited dual adsorption peaks one each at the acidic and alkaline pH regions as solution pH changed from 3 to 11. The rate data fitted (≥0.9232) the homogeneous fractal Pseudo-Second Order (FPSO) better than any other kinetics model, as well as the Freundlich adsorption isotherm model (≥0.9887); these indicate complex interactions between ivermectin and the adsorption sites of both composites. Ambient temperature increase up to ≈30 °C caused higher ivermectin adsorption but beyond this temperature there was drastic drop in adsorption. The KPA and KPC adsorption capacities are 105.3 and 115.8 μg/g, respectively. The KPC was better at reducing ivermecitn in low-concentration solution (≈75 μg/L) to less than 5.0 μg/L compared with KPA with ≈20.0 μg/L. Though KPC showed better efficiency in adsorption capacity and lowering concentration in low-concentration solutions, KPA exhibited better reusability with 83.5 and 67.5% initial adsorption strengths remaining in the second and third adsorption cycles, respectively, compared to the 73.8 and 58.8% for the KPC. These results indicate that KPA and KPC composites have the economic potential for application in water treatment processes.

Application of porous materials in heat exchangers of heat supply system

Heat exchange capacity increase is one of the main concerns in the process of manufacturing modern heat exchange equipment. Constructing heat exchangers with porous metals is an advanced technique of heat exchange increase. A construction of heat exchangers with porous aluminum is described in this paper. The first heat transfer agent (hot water) flows through thin copper tubes installed within the porous aluminum. The second heat transfer agent (freon) flows through the pores of aluminum. Laboratory facility was created to study such a heat exchanger. Series of experiments were carried out. The purpose of the research presented here is to create a mathematical model of heat exchangers with porous metals, to perform analytical calculation of the heat exchangers and to confirm the results with the experimental data. In this case, one can`t use the standard methods of heat exchangers calculation because the pores inner surface area is indeterminate. The developed mathematical model is based on the equation describing the process of cooling the porous plate. A special mathematical technique is used to take into account the effect of tubes with water. The model is approximate but its solution is analytic. It is convenient. One can differentiate it or integrate it, which is very important. Comparison of calculated and experimental data is performed. Divergence of results is within the limits of experimental error. If freon volatilizes inside the heat exchanger, the heat of phase transition has to be taken into account alongside with heat capacity. The structure of the mathematical model makes it possible. The results presented in this paper prove the practicability of using porous materials in heat exchange equipment.

Lab Study on the Effect of Cation Exchange Capacity on Slurry Performance in Slurry Shields

Ion stabilizers can enhance the reinforcement slurry effect on the wall and stabilize the wall actively in slurry shields. This paper presents different cation exchange capacities obtained by changing the content of the ion stabilizer (1.5%, 2.0%, 2.5%, 3.0%, 3.5%, 4.0%, 4.5%, 5.0%, 5.5%, and 6.0%) in slurry associated with the basis of the existing slurry formula through the laboratory tests. In order to study the effect of the cation exchange capacity on the performance of slurry properties, the rheological properties of the slurry are analyzed and evaluated by the power law model. Results indicate that the cation exchange capacity of the slurry decreases first and then increases with the increase of the ion stabilizer content. When the content of the ion stabilizer is maintained at 3.50%, the cation exchange capacity reaches the minimum value of 2.92. The filtration volumes, pH values, and rheological parameters of the slurry also indicate an obvious linear change with the change of the cation exchange capacity. The minimum filtration volume is 9.70 mL/30 min when the ion stabilizer content reaches 3.50%. However, the pH value reaches the maximum, that is, 11.34 which is changed from 10, and the change could be considered as a constant value in the field work. When the cation exchange capacity increases, the continuity of polymer structure in the slurry decreases first and then increases, the flow index and consistency coefficient are located within a reasonable range, and the rheological properties of the slurry meet the design requirements of the standards.

Ion exchange investigation for recovery of uranium from acidic pregnant leach solutions

Abstract The article describes studies on the separation of uranium from acid pregnant leach solutions obtained from Polish uranium ores: dictyonema shales and sandstone rocks. Ion exchange chromatography was applied for uranium sorption, using commercially available, strongly basic anion exchanger, Dowex 1. In model experiments, the influence of degree of crosslinking of Dowex 1 on the efficiency of uranium extraction was investigated. The effect of H2SO4 concentration on the breakthrough curve of uranyl ions for the Dowex 1 resins, of different crosslinking: X4, X8 and X10, was examined. Unexpectedly high increase of exchange capacity of uranium was observed in case of Dowex 1X10. This gives potential opportunity of improving the effectiveness of uranium recovery process. Applying column packed with Dowex 1X10, ‘yellow cake’ with ca. 92% yield and high purity of recovered uranium was obtained. A block diagram of the procedure for uranium and lanthanides extraction from acidic leach liquor has been proposed.

Chemical Attributes of Soil and Forage Yield of Pasture Recovered with Phosphate Fertilization and Soil Management

ABSTRACTExtensive and semi-extensive pastures are the basis of Brazilian livestock production. However, much of it is degraded or in degradation process, with low stocking rate per area. Even with this problem, this management type is 60% and 50% of Australia’s and the United States’ production costs, respectively. In order to research alternatives for Urochloa decumbens degraded pasture recovery in an Oxisol, Stylosanthes (Stylosanthes spp.) “Campo Grande” cultivar was introduced and phosphate fertilization was applied. The experimental design was of randomized blocks, 7 × 2 × 2 factorial design, with four replicates, involving seven systems to introduction (U. decumbens control; partial desiccation with 1.5 L ha−1 glyphosate, total desiccation with 3.0 L ha−1 glyphosate; direct planting; scarification, harrowing, and plowing + harrowing), phosphate fertilizer presence or absence, and two evaluation periods. “Campo Grande” Stylosanthes legume introduction increased shoot dry weight (SDW) yield, except in direct planting. Phosphorus fertilization increased SDW yield only in the first period, and Stylosanthes introduction in the pasture has not changed soil chemical properties. Phosphorus (P) fertilization also provided available P and exchangeable calcium (Ca2+) content in the soil increase, in addition to sum of bases and cation exchange capacity increase.

Balancing of Wind Power Variations Using Norwegian Hydro Power

This paper addresses the role of Norwegian hydro power to provide balancing power to a future wind dominated European power system. Two power market models, one simplified and one detailed are used to model possible responses of Norwegian hydro power to a wind driven exchange pattern for various amounts of exchange capacity. The case analysed assume a 2030 scenario for wind generation in Europe and an increase in exchange capacity between Norway and Europe from 2300 MW to 5800 MW. We find that the generation constraints and the exchange capacity, and not the aggregated reservoir size, are the most important limiting factors for the amount of balancing the Norwegian hydro power system can provide.

Micromorphology and development of loess-derived surface and buried soils along a precipitation gradient in Northern Iran

The northern footslopes of the Alborz Mountains and an extensive hill area in eastern Golestan Province are covered by thick (∼70 m) loess deposits, divided by different types of interstadial and interglacials paleosols. The area shows a precipitation gradient of about 800 mm over 80 km north-south. Along this gradient, eight pedons of modern soils and six paleosols were selected in order to investigate the types of modern and past soil forming processes and to compare the degree of soil development of surface and buried soils. The soils were described and sampled using standard sedimentological/pedological laboratory analysis. The soil pH and calcium carbonate contents show a decreasing trend with precipitation, while soil organic carbon, clay content and cation exchange capacity increase with rainfall. The silt content, however, shows a decreasing trend with rainfall. Clay mineralogy of parental loess is illite > chlorite > smectite > kaolinite. From north to south, the relative proportion of smectite in soil horizons increases, reaching almost dominance in regions with typic xeric soil moisture regime (SMR; ∼600 mm of rainfall). In the areas with udic SMR, vermiculite increases and sometimes dominates. Micromorphology provides evidence for the formation of Bt horizons and intensified decalcification and increase of clay mobilisation as indicated by b-fabrics with increasing rainfall. Soils within the xeric and udic SMRs are either Alfisols or Mollisols, both showing clay illuviation features, whereas clay mobilisation is very limited in the arid part of the area. The paleosols show differential weathering degrees indicated by trends of increasing carbonate depletion, clay mobilisation, and clay enrichment with assumed paleo-precipitation. Pedogenesis, micromorphological properties and clay minerals in the last interglacial paleosols suggest similar climate controlled trends to those reflected in the modern soils.

Restructuring and generation of electrical energy in the Iberian Peninsula

Portugal and Spain are on the threshold of the creation of an Iberian electricity market. In order to help its development, the power of the electric interconnection between the countries has been increased and market mechanisms designed to resolve congestion, should it arise. A system of joint supply for the Iberian Peninsula will lead to single price for the whole area except at times when the interconnection is saturated, in which case prices will be somewhat higher in the importing zone. In the medium term, the hope is that both systems will have very similar generating equipment and that their variable costs will equalize due to the substitution of the most obsolete equipment with combined cycle power stations, and to the increase of exchange capacity. The coming into effect of this market will bring about improvements in the security and efficiency of supply in both countries. There will also be some obstacles to overcome, such as, for example, the current regulatory frame deficiencies on power generation, the contacts which exist at present in Portugal between the producers and the National Electricity Network, the asymmetry of the distribution channels in each country, the differences in rates and the limited capacity for exchange.

The relationship between zeolite (heulandite-clinoptilolite) content and the ammonium-exchange capacity of pyroclastic rocks in Gördes, Turkey

AbstractDiagenetic alteration in two tuff horizons (the lower and upper tuff units) in the GoÈrdes region of Turkey led to the formation of mainly heulandite-clinoptilolite-type zeolites and also clay and silica minerals and K-feldspar. Possible variations in the climate and geological environment followed by variations in the hydrological system and the composition of the Miocene lake water and groundwater at that time resulted in the mineralogical facies. The lower tuffs are unaltered or slightly altered in the northern part and are more altered, particularly to zeolite (clinoptilolite) in the southern part of the study area. Heulandite and K-feldspar are mainly authigenic minerals in the upper tuff unit. The ammonium-exchange capacities of the 16 samples were investigated to understand the effects of the mineralogical composition on their ion-exchange capacities, which vary in the range 0.19-2.00 mEq/g. It is observed that the ion-exchange capacities are strongly dependent on the zeolite contents of the rocks. The correlation coefficient of this linear relation is 0.86. The most significant increase in ammonium-exchange capacity (from 0.2 to ~1.0 mEq/g) was observed when the zeolite contents increased from 0 to 30 wt.%. The second increase in exchange capacity was observed for samples containing >80 wt.% zeolite. Although there is no significant effect from the other authigenic minerals, smectite has a positive effect, and K-feldspar and opal-CT have almost no effect on the ion exchange capacities.

Capillary-electrochromatographic separations with copolymeric reversed-stationary phase and ion-exchanger-packed columns

A macroporous, spherical, 7 μm, polystyrene–divinylbenzene (PS–DVB), reversed-phase adsorbent (PRP-1) was evaluated as a stationary phase for the capillary electrochromatographic (CEC) separation of neutral, acidic, and basic analytes of pharmaceutical interest. Electroosmotic flow (EOF) for a PRP-1 packed capillary is nearly constant over the pH 2 to 10 range and is higher than for a silica-based C 18 packed capillary on the acidic side. EOF increases with an increase in buffer acetonitrile concentration or as applied potential increases. As analyte hydrophobicity increases, analyte retention and migration time increases. Increasing buffer acetonitrile concentration reduces analyte partitioning with the PS–DVB stationary phase and analyte retention and migration time decreases. When exchange sites are present on the PS–DVB copolymer, EOF (EOF is reversed for the anion-exchanger) increases as the exchange capacity increases. An increased exchange capacity also reduces partitioning of the analyte with the PS–DVB matrix and analyte retention and migration time decrease. Because of excellent stability in an acid environment, the PRP-1 packed capillary can be used in strong acid buffer solution and weak acid and base analytes depending on pK a values can be separated as neutral species and cations, respectively. CEC separations on a PRP-1 capillary of neutral steroids, weak base pharmaceuticals (separation as cations), purines and pyrimidines (as cations), fatty acids (as undissociated species), and sulfa derivatives (as cations) are described. Efficiency for the PRP-1 packed capillary for acetone or thiourea as the analyte is about 6·10 4 plates m −1.

Capillary electrochromatography with fused-silica capillaries packed with copolymeric reversed-phase adsorbent and ion exchangers.

Macroporous poly(styrene-divinylbenzene) (PSDVB), PRP-1, a reversed-phase adsorbent, and PSDVB-based strong acid cation exchangers and strong base and weak base anion exchangers were evaluated as stationary phases for capillary electrochromatography (CEC). Electroosmotic flow (EOF) for adsorbent and exchanger packed fused-silica capillaries for acetone as the marker increases with increasing ion exchange capacity, buffer organic solvent concentration, and applied voltage, is nearly independent of pH, and decreases with increased buffer ionic strength. For anion exchangers, EOF is reversed. Thiourea, acetone, acrylamide, nitromethane, propanal, and acetic acid were evaluated as EOF markers and undergo weak interaction with the PSDVB-based stationary phases. EOF in a basic buffer is greater than or equal to silica-based C-18 and cation exchanger packed capillaries. For an acidic buffer, EOF for a PRP-1 capillary is almost twice the C-18 packed capillary. As analyte hydrophobicity increases, retention and migration time increases for the PSDVB-based stationary phases. As exchange capacity increases, availability of the polymeric matrix for analyte partitioning decreases, causing analyte migration time to decrease. Increasing buffer organic solvent concentration decreases analyte retention. The PSDVB-based stationary phases provide good resolving power and reproducibility and are applicable to the CEC separation of neutral, weakly acidic, and basic analytes. Efficiency, however, is less than obtained with silica-based stationary phases. Because of stability in a strong acid buffer, the CEC separation of weak acids, where dissociation is suppressed, and weak bases as cations is possible. Separations of short-chain alkyl aldehydes, methyl ketones, aromatic hydrocarbons, substituted benzene derivatives, and short-chain carboxylic acids are described.

Semi-interpenetrating networks (sIPN). Preparation of ion-exchange membranes, using a gaseous crosslinking reagent

In this work we have brought to the fore the preparation of semi-interpenetrating polymer network by using a crosslinking gaseous reagent. By treating the mixture of poly(vinyl alcohol) (PVA) and a polyelectrolyte (P) as poly(sodium styrene sulfonate) (PSSNa), poly(acid acrylic) (PAA) and poly(1,1-dirnethyl-3,5-dimethylenepiperidium chloride) (PDMeDMPCI) with gaseous dibromoethane, we have obtained three ion-exchange membranes which have good physico-chemical properties depending on the preparation and crosslinking conditions. From this study, an increase of exchange capacity and a decrease of the swelling ratio with crosslinking time (or crosslinking rate) was observed. The average capacity was 1.5, 0.8 and 6 mequiv/g for PVA/PSSNa, PVA/PDMeDMPCI and PVA/PAA, respectively. It depended also on the weight fraction of the crosslinkable polymer. The best results were obtained for samples containing 55% PVA and 45% P

Evaluation of Technical and Economical Benefits of a Phase Shifting Transformer on the Interconnection between France and Spain

The interconnection between France and Spain could be a good illustration of the case where environmental constraints imply that utilities are led to consider various possibilities such as FACTS or other classical devices to augment the electric power that is transported in their system while limiting the need of network development. At the beginning of 1996, the French Government decided to delay a 400 kV line construction that should link the two partners and asked for additional studies to lead to a new reinforcement solution. For this reason, EDF and REE agreed to equip the 225 kV Pragnères Biescas circuit with a 50°/310MVA Phase Shifting Transformer to improve the interconnection behavior until the commissioning of the new solution. Such reinforcement cannot be considered as a long term solution because it produces a very limited increase of exchange capacity. This device will be the first one installed on the French system.

Genistein Inhibits Na+/Ca2+Exchange Activity in Primary Rat Cortical Neuron Culture

We have examined the possible regulatory effect of tyrosine kinase activity on Ca2+transport observed in the cultured rat cortical neurons. Na+/Ca2+exchange was studied using cells cultured for various time periods. A nearly two fold increase in Ca2+uptake was seen when comparing 3 day and 9 day cultures. Western blot analysis also showed a two fold increase in Na+/Ca2+exchanger (NCX1) protein levels as cells matured in culture. To study the effect of genistein (a specific tyrosine kinase inhibitor) cells were incubated with 100μM genistein (in 1% DMSO) for 1 hour before the assay of Na+/Ca2+exchange activity. There was a significant decrease of Ca2+uptake in genistein treated neurons (control: 4.596±0.205 nmol/mg protein/15min, n=12; genistein: 1.420±0.131 nmol/mg protein/15min, n=12, mean±S.E. P<0.001). Daidzein, an inactive analog of genistein and phorbol myristate acetate (PMA), a PKC activator were without effect. The results suggest that as cells mature in culture, Na+/Ca2+exchange capacity increases, as a result of greater protein expression. Exposure to genistein inhibited Ca2+uptake suggesting that the exchanger may be modulated by tyrosine phosphorylation.

VARIATION OF SOIL CHEMICAL PROPERTIES OVER NIGERIAN SAVANNA

ABSTRACTAn analysis of relationships between selected soil chemical properties and parameters of parent material, climate and relief was undertaken for the savanna of north central Nigeria. Step by step examination of individual properties and the environmental parameters reveals numerous invariably disparate relationships often explicable in terms of local conditions. However, an analysis of covariance involving all variables shows that variations in base elements and cation exchange capacity are more strongly related to lithology than climatic or relief parameters. Soil pH and base saturation percentage, on the other hand, are influenced more by rainfall than parent material, altitude and slope position. Temperature and slope gradient are relatively unimportant in the variability of all soil properties. On the whole, the soil properties show significantly greater values over basalt, shale and alluvium than gneiss, schist and colluvium which in turn show greater values than sandstone, granite, granite gneiss, aeolian and ironpan‐rich deposits. Exchangeable cations and cation exchange capacity increase with an increase in rainfall, altitude and downslope position while pH and base saturation per cent show a decreasing trend.

Effects of the application of pig slurry on some physico-chemical and physical properties of calcareous soils

The effects of adding pig slurry to two calcareous soils containing different levels and types of clay were studied over a period of two years. Doses up to 1000 m 3 ha −1 year −1 were used and the evolution of some physico-chemical (cationic exchange capacity and pH) and physical (porosity and water holding capacity) properties was studied. The exchange capacity increased as more slurry was added when the soil had a low clay content, giving rise to a good correlation between the values for organic carbon and exchange capacity. In soils of a higher clay content, the increase in exchange capacity was not so significant. pH decreased with the addition of slurries, possibly due to the liberation of exchangeable ammonium and its subsequent nitrification.

Simultaneous flow of water and solutes through geological membranes—I. Experimental investigation

The relative retardation by geological membranes of cations and anions generally present in subsurface waters was investigated using a high pressure and high temperature ‘filtration cell’. The solutions were forced through different clays and a disaggregated shale subjected to compaction pressures up to 9500 psi and to temperatures from 20 to 70°C. The overall efficiences measured increased with increase of exchange capacity of the material used and with decrease in concentration of the input solution. The efficiency of a given membrane increased with increasing compaction pressure but decreased slightly at higher temperatures for solutions of the same ionic concentration. The results further show that geological membranes are specific for different dissolved species. The retardation sequences varied depending on the material used and on experimental conditions. The sequences for monovalent and divalent cations at laboratory temperatures were generally as follows: Li < Na < NH 3 < K < Rb < Cs Mg < Ca < Sr < Ba. The sequences for anions at room temperature were variable, but at 70°C, the sequence was: HCO 3 < I < B < SO 4 < Cl < Br. Monovalent cations contrary to some field data were generally retarded with respect to divalent cations. The differences in the filtration ratios among the divalent cations were smaller than those between the monovalent cations. The passage rate of B, HCO 3, I and NH 3 was greatly increased at 70°C.

Retention of Dissolved Constituents of Waste by Geologic Membranes: ABSTRACT

Clays and shales serve as semipermeable membranes, retarding by varying degrees the passage of the dissolved species with respect to water. The relative retardation by geologic membranes of cations and anions generally present in waste solutions was investigated using a high temperature filtration cell. The solutions were forced with varying hydraulic gradients through different clays and a disaggregated shale subjected to compaction pressures up to 10,000 psi and to temperatures from 20 to 90°C. The efficiencies measured increased with increase of exchange capacity of the material used and with decrease in concentration of the input solution. The efficiency of a given membrane increased with increasing compaction pressure, but decreased at higher temperatures and higher hydraulic gradients for solutions of the same ionic concentration. The results further show that geologic membranes are specific in that the degree of retardation is different in different dissolved species. The retardation sequences obtained varied depending on the material used and on experimental conditions. The retardation sequences for monovalent and divalent cations were generally as follows: Li 3 Mg The retardation sequences for anions at room temperature were variable, but at higher temperatures the sequence was: HCO34 Monovalent cations generally were retarded with respect to divalent cations at the higher hydraulic gradients. This trend, however, was reversed at the lower hydraulic gradients. Extrapolation of the results to average hydraulic gradients encountered in subsurface formations indicates agreement with data obtained from field investigations which show that divalent cations generally are retarded with respect to monovalent cations. End_of_Article - Last_Page 1598------------

Fertility and productivity of a podzolic soil as influenced by subterranean clover (Trifolium subterraneum L.) and superphosphate.

A survey was made of the influence of the use of superphosphate and subterranean clover (Trifolium subterraneum L.) on podzolic soils formed on granodiorite in the Crookwell district of New South Wales (average rainfall, 32.7 in. per annum). Forty-four paddocks were sampled; they varied from untreated native pasture to paddocks which had been for 26 years continuously under clover and which had received a total of 13 cwt of superphosphate per acre. In all instances there had been no cultivation during treatment, and the land use mas uniformly one of sheep raising, principally for wool but with some emphasis on fat lamb production on highly improved pastures. Criteria used in this study were the changes in yield and botanical composition of the pasture, changes or trends in the chemical composition of the 0-4 in. depth of soil, and the yield of oats produced by each of the soils in pot culture with varying superimposed applications of phosphorus, sulphur, and nitrogen. The native pasture species disappear under the competition by subterranean clover, which gives a fourfold increase in the yield of pasture. Within the limits of experimental error, the phosphorus and sulphur applied as superphosphate, even that applied many years previously, can be accounted for in the surface 4 in. of soil. Losses by removal in wool and carcases are small. The added phosphorus is present in approximately equal amounts as organic phosphorus and readily extractable inorganic phosphorus. The applied sulphur appears to become a part of the organic complex. Eighty-five pounds of nitrogen has been added in the surface 4 in. of soil by rhizobial activity for each hundredweight of superphosphate applied per acre. Initially the most acute deficiencies affecting plant growth on these soils are those of phosphorus and nitrogen, with a less pronounced deficiency of sulphur. After a period of several years of superphosphate and clover, each of these deficiencies is much reduced, the order of the intensity of deficiencies then being nitrogen, sulphur, and phosphorus. Soil pH falls with superphosphate application at the rate of about 0.06 units per hundredweight of fertilizer per acre, but may reach an equilibrium value at about 5.1. This could be due to the increase in exchange capacity of the soil as a result of the increase in organic matter. A field experiment on two sites also indicated the increase in fertility under subterranean clover pasture and demonstrated the capacity of the improved soils to produce a satisfactory field crop of oats.