Cent CaCO3 Research Articles

Mapping of macronutrient status in soils of Gaganbawda tehsil of Kolhapur district using GPS-GIS technique

The present study entitiled “GPS-GIS based soil fertility maps of Gaganbawda tehsil of Kolhapur district (M.S.)” was conducted during year 2016-2017, by using Global Positioning System (GPS) and Geographical Information System (GIS). Soil samples were analysed for pH, EC,OC, Per cent CaCO3 equivalent, available macronutrients N,P,K,S, Exchangeable Calcium, magnesium and sodium. The availability of macronutrient and their relationship with soil properties were studied. The soil pH varied from 4.86 to 6.94 with a mean value 5.77 and indicated that strongly acidic to slightly acidic in reaction. The EC of soil varied from 0.10 to 0.32 dSm-1 (mean value 0.15) and indicated that 100 per cent soils were noraml in nature. The per cen CaCO3 equivalent content and organic carbon content ranged from0.37 to 2.25 and 0.58 to 1.80 per cent with a mean value 1.37 per cent and 1.20 per cent respectively. The soils of Gaganbawda tehsil were baerely calcareous to moderatly calcerous and moderate to very high in organic carbon content. The available macronutrients N, P, K and S ranged from 161.50 to 385.72 kg ha-1, 4.48 to 14.33 kg ha-1, 100.80 to 380.80 kg ha-1 and 10.82 to 24.15 mg kg-1 respectively. Soils were low to moderate in available nitrogen, very low to moderate in available in phosphrous, moderate to very high in available potassium and moderate to high in available sulphur. The exchangeble calcium, magnesium and sodium ranged from 2.20 to 10.40 [Cmol(p+) kg-1], 0.30 to 7.10 [cmol(p+)kg-1] and 0.10 to 0.52 [cmol(p+)kg-1]. Exchangeable calcium and magnesium were 100% deficient. Organic carbon showed positive significant correlation with available K and negative significant corrleation with sulphur. CaCO3 showed positive significant correlation with potassium, calcium and magnesium.

The influence of normal stress and sliding velocity on the frictional behaviour of calcite at room temperature: insights from laboratory experiments and microstructural observations

Abstract The presence of calcite in and near faults, as the dominant material, cement, or vein fill, indicates that the mechanical behaviour of carbonate-dominated material likely plays an important role in shallow- and mid-crustal faulting. To better understand the behaviour of calcite, under loading conditions relevant to earthquake nucleation, we sheared powdered gouge of Carrara Marble, >98 per cent CaCO3, at constant normal stresses between 1 and 100 MPa under water-saturated conditions at room temperature. We performed slide-hold-slide tests, 1–3000 s, to measure the amount of static frictional strengthening and creep relaxation, and velocity-stepping tests, 0.1–1000 μm s–1, to evaluate frictional stability. We observe that the rates of frictional strengthening and creep relaxation decrease with increasing normal stress and diverge as shear velocity is increased from 1 to 3000 μm s–1 during slide-hold-slide experiments. We also observe complex frictional stability behaviour that depends on both normal stress and shearing velocity. At normal stresses less than 20 MPa, we observe predominantly velocity-neutral friction behaviour. Above 20 MPa, we observe strong velocity-strengthening frictional behaviour at low velocities, which then evolves towards velocity-weakening friction behaviour at high velocities. Microstructural analyses of recovered samples highlight a variety of deformation mechanisms including grain size reduction and localization, folding of calcite grains and fluid-assisted diffusion mass transfer processes promoting the development of calcite nanograins in the highly deformed portions of the experimental fault. Our combined analyses indicate that calcite fault gouge transitions from brittle to semi-brittle behaviour at high normal stress and slow sliding velocities. This transition has important implications for earthquake nucleation and propagation on faults in carbonate-dominated lithologies.

Effects of CaCO3 whisker on the sliding wear behaviour of poly(etheretherketone) under water-lubricated condition

Polyetheretherketone (PEEK) composite specimens filled in 0–30 wt% content of CaCO3 whisker were prepared by compression moulding. Tribological testing of composites was carried out on an MM200 block-on-ring apparatus in water lubricated wear mode against carbon steel. The morphologies of wear traces were observed by scanning electron microscopy (SEM). The effects of CaCO3 whisker on the mechanical and tribological properties of composites were investigated. It was revealed that the inclusion of CaCO3 whisker significantly improved the wear resistance and reduced the friction coefficient of PEEK composites under water-lubricated condition. With an increase in CaCO3 whisker contents, the friction coefficient decreased and showed minima for 15 per cent CaCO3 inclusion. The specific wear rate of composites showed minima as 2.04×10−6 mm3/N m for 20 per cent CaCO3 inclusion as 5.2 per cent of that for pure PEEK, followed by a slow increase for further CaCO3 whisker addition. In terms of friction applications under water lubrication, when the tribological and mechanical properties were combined, the optimal content of CaCO3 whisker in the filled PEEK should be recommended as 15–20 per cent. The SEM observation of the wear traces indicated that CaCO3 whisker contributed to increase the load-carrying capacity and abate the scuffing and adhesion of filled composites, which conformed to the better wear resistance of CaCO3/PEEK composites than pure PEEK. No transfer film could be observed on the counterface of the mating ring under water-lubricated condition. It is confirmed that the transfer film is not the main reason for the enhancement of wear resistance of the composites in water lubrication.

Thermomechanical properties and tribological behaviour of CaCO3 whisker-reinforced polyetheretherketone composites

The thermal expansion properties, dynamic mechanical properties, and related tribological properties of polyetheretherketone (PEEK) composites filled with 0–25 wt.% content of calcium carbonate (CaCO3) whisker were investigated. The composite specimens were prepared by compression moulding. Thermomechanical analysis (TMA) was performed to determine linear coefficients of thermal expansion (CTE). Dynamic mechanical thermo-analysis (DMTA) was employed within the temperature range of 25–300 °C. Tribological testing of composites in dry wear mode against a carbon steel ring was carried out on a MM200 block-on-ring apparatus. All specimens show a large change in CTE at glass transition temperature ( Tg), but CTEs of CaCO3/PEEK composites at temperatures below and above Tg are much lower than pure PEEK. For 25 per cent CaCO3/PEEK the average CTE in the temperature range of 25–120 °C is about half lower than PEEK. CaCO3 whisker shows a significant effect on the dynamic stiffness at low and high temperatures. The increase of whisker content contributes to a rise to the storage modulus. CaCO3-whisker-filled PEEK composites exhibit considerably lower friction coefficient and wear rate than pure PEEK. With an increase in CaCO3 whisker contents, coefficient of friction of PEEK composites continuously decreases, while the specific wear rate shows minima for 15 per cent CaCO3 whisker inclusion with an approximate seven times improvement in comparison with PEEK. The improved tribological performance of CaCO3/PEEK composites is ascribable to the reinforcing effectiveness of CaCO3 whisker, which contributes to increase the thermal stability, stiffness, and load-carrying capacity of PEEK composites in terms of counteracting the effects of thermal softening and adhesion during the friction process.

Impacts of Bauxite Sediment Inputs on a Carbonate-Dominated Embayment, Discovery Bay, Jamaica

Sub-tidal, reef-lagoon surficial sediment samples from Discovery Bay, north Jamaica were analysed in order to quantify the impacts of anthropogenic bauxite inputs on trace metal (Fe, Zn, Mn) levels and sediment characteristics. Contaminant levels exhibit marked spatial variations, but are highest across central and southern parts of the bay and primarily reflect wind blown inputs, modified by subsequent suspended sediment transport. Highest contaminant levels (Fe—13,701 ppm, Mn—237 ppm, Zn—74 ppm) occur immediately adjacent to, and just north-east of, a bauxite loading terminal in the south-west of the bay. Sites of high sediment contamination are negatively correlated with per cent CaCO3 content, indicating the diluting effect of bauxite on the carbonate substrate. At high contamination sites CaCO3 levels are reduced to 63.7% and are in the range of 75–80% across much of the central and southern area of the bay. Magnetic susceptibility level measurements are positively correlated with iron and negatively correlated with CaCO3 content, and indicate the potential for using magnetic susceptibility measurements in metal contaminant tracing studies in carbonate environments. Whilst metal contamination levels are low compared with many clastic-dominated systems, and are currently at levels unlikely to impact the reef biota, the data indicate both the progressive contamination of this previously carbonate-dominated lagoon environment, and the potential for such terrestrial inputs to impact upon sediment characteristics in such restricted settings.

Magnetostratigraphy of Early Cretaceous Maiolica sections of the Southern Alps (Cismon and Pra da Stua, Italy)

The bottom part of the Cretaceous Cismon section in the Southern Alps was sampled for high-resolution magnetostratigraphy. Although the almost pure pelagic nannofossil limestones (c. 90 per cent CaCO3) of the Maiolica/Biancone Formation are extremely weakly magnetized, stepwise thermal and alternating-field demagnetization removed overprints and isolated a characteristic remanent magnetization which is interpreted as a primary magnetization. The dominant magnetic carrier mineral is magnetite; a small fraction of haematite may be present. A clear reversal pattern can be correlated unambiguously with Mesozoic polarity chrons CM10N to CM8. A less well-constrained magnetostratigraphy from the Pra da Stua section could not be directly correlated with the global polarity scale, but biostratigraphic information allows its assignment to the interval CM10-CM5. A counterclockwise rotation of 56° and a northward translation of 28° latitude for the Cismon locality since the Early Cretaceous are derived from the palaeomagnetic data, consistent with previous results from the Southern Alps. The high-resolution magnetostratigraphy of the Cismon section is used in an effort to refine the Cretaceous timescale by the combination of magnetostratigraphic and cyclostratigraphic results from the same section. The cyclostratigraphic duration estimates of chrons CM10N to CM8 are compared to their equivalents in a number of traditional timescales and found to be shorter by a factor of 1.26–2.58.

CALCIUM BORON INTERACTION IN THE SOILS GROUNDNUT

This study explains calcium-boron interactions in groundnut plants grown the RE3 treated with 0, 10, 20 and 30 per cent CaCO3 and 0, 0.5, 1.0 and 2.0 ppm boron The calcium-boron interaction of the soil were also explained by post harvest soil analysis and boron adsorption studies in the laboratory.

Genesis of marine terrace soils, Barbados, West Indies: Evidence from mineralogy and geochemistry

AbstractWell‐developed, clay‐rich soils dominated by interstratified kaolinite‐smectite are found on the uplifted coral reef terraces on the island of Barbados. The reef limestone is unlikely to have been the soil parent material however, because it is 98 per cent CaCO3 and geomorphic evidence argues against the 20 m of reef solution required to produce the soils by this process. The mineralogy of the sand, silt, and clay fractions of the soils, and trace element geochemistry, suggest that aeolian materials carried on the trade winds from Africa, volcanic ash from the island of St. Vincent, and quartz from Tertiary bedrock on the island itself are the parent materials for the soils.

The effect of lime on the response of soils to sodic conditions

SummaryThe role of CaC03 in preventing clay dispersion and losses in hydraulic conductivity (HC) of sodic soils was determined directly by mixing two lime‐free soils with 0.5 and 2.0 per cent CaCO3. Whereas the HC of the lime‐free soils dropped sharply when 0.01 n solutions of SAR 20 were displaced with distilled water, mixing the soils with powdered lime prevented both HC losses and clay dispersion. The response of a sandy soil mixed with lime was similar to that of a calcareous sandy soil. The beneficial effect ofCaC03 was not so pronounced in soils equilibrated with solutions of SAR 30. The increase in electrolyte concentration, due to CaCO3 dissolution, was suggested as the mechanism responsible for the beneficial effect of lime.

Effect of soil application of CaCO3 and Fe on dry matter yield and nutrient uptake in oats (Avena sativa)

The effects of CaCO3 and Fe on the dry matter yield and uptake of P, Ca, Mg, Fe and Mn were studied in the green-house on oats (Avena sativa) grown on light-textured soil. Dry matter yield increased by 14, 25, and 30 per cent at 2, 4 and 8 per cent CaCO3 over control in absence of iron. Application of iron upto 20 ppm also increased dry matter yield significantly over control. Both CaCO3 and iron exercised a synergistic effect on dry matter yield. Concentration and uptake of phosphorus decreased significantly with increasing level of CaCO3 and iron application. Application of CaCO3 increased concentration and uptake of calcium significantly. Concentration of calcium decreased at 5 and 20 ppm of iron in absence of added CaCO3 over control but its concentration and uptake increased with increasing amounts of iron in the presence of added CaCO3. Application of CaCO3 and iron decreased concentration and uptake of Mg. Concentration of Fe increased at 20 ppm of applied iron in absence of added CaCO3 over control but decreased in the presence of added CaCO3. Increasing amounts of CaCO3 decreased concentration and uptake of iron drastically in presence and absence of applied iron. Iron and CaCO3 decreased drastically the concentration and uptake of Mn in oats.

Effect of farm yard manure and CaCO3 on the dry matter yield and nutrient uptake by oats (Avena sativa)

A pot culture experiment was conducted in loamy sand soil to study the effect of different levels of FYM and CaCO3 on the dry matter yield and nutrients uptake by oats. Application of different levels of CaCO3 (0, 2, 4 and 8%) and FYM (0, 0.5, 1,2%) resulted in significant increase in dry matter yield of oats. But, a little decrease in dry matter yield was obtained at 4% FYM. The interaction of FYM×CaCO3 was also significant on dry matter yield of oats. There was a significant decrease in the concentration and uptake of P with increased levels of applied CaCO3. But, application of FYM resulted in a significant increase in concentration and uptake of P. A significant increase in concentration and uptake of Ca was observed with the increasing levels of CaCO3. The concentration of Ca decreased with the increased application of FYM in the presence as well as in the absence of added CaCO3. However, at 0.5 and 1.0 percent FYM with 4 per cent CaCO3 a little increase in Ca concentration was recorded. The Mg concentration in oat decreased significantly with the increasing levels of CaCO3 and FYM. The effect of CaCO3 levels was more pronounced in the absence as well as in the presence of FYM. The Mg uptake followed a different pattern. At 0 and 2% CaCO3 and application of FYM @ 1 per cent the Mg uptake increased but then it decreased with increasing levels of FYM and CaCO3 both alone as well as in the presence of each other. The concentration and uptake of Mn decreased with increasing levels of applied CaCO3. However, in the absence of CaCO3, the application of FYM increased the concentration and uptake of Mn in oats. In the presence of CaCO3, Mn concentration decreased at all levels of FYM application but at 8 per cent CaCO3 there was a slight increase in Mn concentration with 0.5, 2 and 4 percent FYM. Iron concentration and uptake was also affected adversely by increasing levels of CaCO3 but FYM application removed the harmful effect of CaCO3 to some extent.

Yield of submerged paddy and uptake of Zn, P and N as affected by liming and Zn fertilizers

The effects of CaCO3, Zn sources and levels on the yield of submerged paddy and uptake of Zn, P and N to paddy were studied in green-house at Haryana Agricultural University, Hissar. Powdered CaCO3 was mixed at 0,4 and 8 per cent and Zn was added at 0,5 and 10 ppm through ZnSO4.7H2O, ZnO and Zn EDTA separately. Dry weight at tillering and heading and grain and straw at maturity decreased significantly with 4 and 8 per cent CaCO3 in comparison to the control. Increasing Zn application increased the dry weight and grain yield. Zn EDTA gave highest yield of paddy followed by ZnSO4.7H2O and ZnO.

THE HIGH‐ AND LOW‐ENERGY PHOSPHATE ADSORBING SURFACES IN CALCAREOUS SOILS

SummaryThe two‐surface Langmuir equation was used to study P adsorption by 24 calcareous soils (pH 7.2‐7.6; 0.8‐24.2 per cent CaCO3) from the Sherborne soil series, which are derived from Jurassic limestone. High‐energy P adsorption capacities (x″m) ranged from 140–345 μg P/g and were most closely correlated with dithionite‐soluble Fe. Hydrous oxides therefore appear to provide the principal sites, even in calcareous soils, on which P is strongly adsorbed (x″m 6–51 ml/μg P). The low‐energy adsorption capacities (x″m) ranged from 400–663 μg P/g and were correlated with organic matter contents and the total surface areas of CaCO3 but not with per cent CaCO3, pH, or dithionite‐soluble Fe. Total surface areas of CaCO3 in the soils ranged from 4.0 to 8.5 m2/g soil. Low‐energy P adsorption capacities agree reasonably with values (100 pg P/m2) for the sorption of phosphate on Jurassic limestones but phosphate was bonded much less strongly by soil carbonates (k″= 0.08–0.45 ml/μg P) than by limestones (k∼10.0 ml/μg P). Low‐energy P adsorption in these soils is tentatively ascribed to adsorption on sites already occupied by organic anions (and probably also by bicarbonate and silicate ions) which lessen the bonding energy of co‐adsorbed P.

The effect of granule size of compound fertilizers on barley crops grown in calcareous soils

The effect of variations in the granule size of compound fertilizers on dry matter, grain yield and nutrient uptake of barley was evaluated in three field experiments on the calcareous soil (> 80 per cent CaCO3) of southern Yorke Peninsula, South Australia. This soil has a high capacity to fix applied phosphorus and manganese. The fertilizers contained superphosphate, manganous and cupric sulphates, and, in two experiments, elemental sulphur as well. The fertilizers were banded with the seed. In all experiments, small fertilizer granules with diameters less than 2.1 mm produced greater grain 5elds than the larger granules. In two of the three experiments, a commercial-sized fertilizer (< 4.8 mm diam.) produced yields similar to those of the small granules. In two of the experiments, plant dry weight, phosphorus and manganese uptake was also significantly increased with decreasing granule size, particularly during rapid plant growth from mid-tillering to late stem extension. This response was more pronounced where the phosphate application rate was suboptimal. In the third experiment, conducted in a year of above average rainfall, the responses were variable and usually not significant. From measurements of granule distribution we suggest that the greater plant response to small granules is due to the better distribution of fertilizer within the soil. This appears to increase contact between plant roots and fertilizer and hence increases the nutrient uptake by the crop.

On the determination of soil carbon

Determinations of organic carbon on 12 carbonate-free terra rossa soil samples from Cyprus with the Walkley-Black method and the Allison reference method showed degree of carbon recovery with the Walkley-Black method ranging between 69.5 and 79.0 per cent. Determinations of organic carbon on 15 carbonaceous (21–28 per cent CaCO3) alluvial soil samples with the method of Allison gave erratic results apparently because the carbonate could not be quantitatively removed prior to organic-C determination.

Correction of manganese deficiency in barley crops on calcareous soils. 1. Manganous sulphate applied at sowing and as foliar sprays

Barley was grown in six field experiments from 1963 to 1969 on calcareous (>80 per cent CaCO3) soils of southern Yorke Peninsula, South Australia. Manganous sulphate was applied to the soil at sowing at 0 to 16 kg ha-1 Mn and to the plants as foliar sprays (1.3 - 1.8 kg ha-1 Mn per application). The effects on shoot and root growth, and manganese uptake in the shoots were measured during the season, and grain yields were determined. Application of manganous sulphate to the soil at sowing increased shoot and root growth and the manganese content of the shoots, and progressively delayed the appearance of manganese deficiency symptoms. However, all crops showed symptoms by the time of stem extension irrespective of the amount of manganese applied to the soil. The maximum grain yield response to soil application was obtained with 6 kg ha-1 Mn. Foliar application of manganous sulphate delayed the appearance of deficiency symptoms and increased grain yield in three of the experiments. Two or three sprays were more effective than a single spray, particularly where no manganese was applied to the soil at sowing. A combination of both soil and foliar application of manganous sulphate (6 kg ha-1Mn added to the soil at sowing and two or three foliar sprays) produced the highest grain yields and usually prevented the occurrence of deficiency symptoms.

Growth and carcase quality of lambs fed concentrate rations in a feedlot

Two feedlot experiments were conducted during 1967 and 1968 using crossbred lambs and concentrate rations. In experiment 1, in 1967, seven rations at three crude protein levels (approximately 15, 21, and 29 per cent) and with various constituents were fed to lambs selected at 50 lb bodyweight. Three rations were in both the pelleted and the dry mash form. Growth rate, efficiency of feed conversion, and carcase quality were measured. After an initial period of twelve days, when all lambs lost weight, lambs on the pelleted diets grew faster than those on the mash diets, but there were no differences due to protein level or to the various constituents in the diets. In experiment 2, in 1968, three pelleted diets were compared, two at low and high crude protein from experiment 1 (17 and 31 per cent), and the third at 19 per cent. Four treatments were included within each diet to overcome the initial period of weight loss : a. diet alone, b. diet and 30 per cent hay decreasing to none after 12 days, c. diet with 3 per cent calcium carbonate included throughout the experiment, d. diet with 3 per cent CaCO3 included, plus hay for the first 12 days. Hay overcame the initial weight loss and low rumen pH, but subsequently the lambs fed the lowest protein diet with 3 per cent CaCO3 grew faster and were the most efficient. Dry matter digestibility and nitrogen retention were also compared in a metabolism trial for the three diets in experiment 2.

Effect of liming on the fate of applied superphosphate phosphorus in some mineral soils

The effect of liming on the distribution of superphosphate phosphorus in various fractions of soil phosphorus was studied. Samples of four mineral soils (pH 3.9 to 5.1) were incubated at room temperature for eight months with 0, 0.5, or 1.0 per cent CaCO3, and with 0.40 per cent superphosphate or without any phosphate application. Liming increased the soil pH-values to pH 6.1—7.3. Samples were analyzed for inorganic phosphorus by the fractionation method of CHANG and JACKSON. Results obtained after an incubation period of four months showed that, both in the fertilized and unfertilized samples, liming had increased the fluoride soluble, acid soluble and easily soluble fractions, but it had decreased the alkali soluble phosphorus. These effects were generally the more distinct, the higher the application of CaCO3 had been. During the prolonged incubation, the alkali soluble fraction tended to increase at the expense of the fluoride soluble phosphorus. The differences in the phosphorus content of various fractions in the respective fertilized and unfertilized samples showed that the »superphosphate phosphorus» was mainly recovered as the fluoride soluble and alkali soluble forms, the relative amount of the latter being the lower the heavier the liming had been. Yet, even at about pH 7, from one fifth to one fourth of the applied phosphorus appeared to be sorbed by iron compounds and ocurred in the alkali soluble fraction. The sum of the proportions of easily soluble and fluoride soluble phosphorus increased with liming. The small parts of fertilizer phosphorus recovered in the acid soluble form did not depend on the rate of liming. Thus, even at pH 7, no significant turning of superphosphate phosphorus in difficultly soluble apatite like secondary calcium phosphates could be detected. The effect of liming on the availability of the fertilizer phosphorus and on the phosphate retention pattern of the soil, was discussed.

Effect of liming on the mobilization of soil phosphorus

The effect of liming on the soil phosphorus fractions was studied under the laboratory conditions. 28 samples of mineral soils (pH in 0.01 M CaCl2 suspension 4.0 to 6.0) were incubated with 1 per cent CaCO3 or without lime for six months at about 18—20°C. In an other experiment, six samples (pH from 3.3 to 4.3) were incubated with 0, 0.5, 1, or 2 per cent CaCO3 also for six months. At the end of the incubation period the soil pH in the limed samples of the first experiment ranged from pH 5.9 to pH 7.5, in the second experiment the highest application kept the soil pH at 6.5 to 7.0. In the air-dried samples the content of organic phosphorus and the fractions of inorganic phosphorus were determined, and the increases or decreases due to the incubation and liming were calculated. Incubation without lime brought about decrease in the organic phosphorus content of several samples, and the presence of lime tended to intensify this effect, although only in a few cases the decrease due to liming was statistically significant. Liming also tended to increase the accumulation of NH4F-soluble inorganic phosphorus. The acid-soluble fraction was often increased in the limed samples but not in the unlimed ones. The alkali-soluble fraction was decreased in most soils in the limed samples, while it increased in some of the unlimed ones. In the second experiment the incubation caused marked decrease in the alkali-soluble phosphorus without a corresponding increase in the other phosphorus fractions determined in the subsoil samples. It was concluded that in these experiments the relatively heavy liming in the first place affected the distribution of inorganic phosphorus increasing the NH4F-soluble and acid-soluble forms at the expense of the alkali-soluble fraction. The effect on the mineralization of organic phosphorus seemed to be in most soils of minor importance.

Effect of incubation and liming on the phosphorus fractions in soil

Samples from two field trials were incubated at 20°C for seven months with or without an addition of 1 per cent CaCO3. Both the samples of loam soil and silt soil originated from the surface inch of plots treated with no phosphate, superphosphate or hyperphosphate, resp. It was found that liming did not in any case increase the amount of organic phosphorus mineralized during the incubation. Its effect was observed in the distribution of this phosphorus in the various fractions of inorganic phosphorus. In the distinctly acid samples which were incubated without lime the mineralized phosphorus seemed to accumulate as the ammonium fluoride-soluble and alkali-soluble forms, while in the neutral samples incubated with lime an increase only in the former fraction was detected. When the samples from the hyperphosphate plots were incubated without lime, apparently some apatite of the fertilizer was dissolved and sorbed as the ammonium fluoride soluble or alkali-soluble forms. No decrease in the acid-soluble fraction of these samples incubated with lime did occur.