scholarly journals Forms of newly retained phosphorus in mineral soils

1964 ◽  
Vol 36 (1) ◽  
pp. 65-76
Author(s):  
Armi Kaila
Keyword(s):  
Organic Carbon ◽  
Sorption Capacity ◽  
Soluble Fraction ◽  
Fine Sand ◽  
Clay Soils ◽  
Soluble Phosphate ◽  
Mean Values ◽  
Phosphate Sorption ◽  
Soluble Phosphorus ◽  
Mineral Soils

The distribution of soluble phosphate in various fractions of soil phosphorus was studied by treating 1 g-samples of 180 mineral soils with 50 ml of a KH2PO4- solution containing P 5 mg/l for 24 hours, and carrying out the fractionation by the method of CHANG and JACKSON after the solution was removed and the moist samples had stood for 3 days at room temperature. The amount of retained phosphorus in the different fractions was computed by taking the difference between the treated and check samples. In the 70 samples of clay soils, the mean proportion of the retained phosphorus was 57 per cent of the 250 mg/kg applied, in the 62 samples of the sand and fine sand soils the corresponding part was 45 per cent, and in the 48 samples of loam and silt soils it was 44 per cent. The higher retention in the clay soils was mainly due to a higher retention in the alkali-soluble fraction. The net increase in the fluoride-soluble forms was of the same order in these three soil groups. On the average, more than 95 per cent of the sorbed phosphorus was found in the fluoride-soluble and alkali-soluble fractions. In one third of the samples a low net increase in the acid soluble fraction was detected, but this may be partly due to changes in the solubility of the native phosphorus in the treated samples. Owing to the fairly large variation, the tendency to somewhat higher mean values for the sorption in the subsoils compared with those of the topsoils was not statistically significant. The ratio between the sorbed amounts of fluoride-soluble and alkali soluble forms was higher in the sand and fine sand soils than in the clay soils. Only in 15 samples, most of them Litorina-soils, the net increase in the alkali-soluble forms was higher than in the fluoride-soluble fraction. Probably, because an equilibrium in the phosphorus conditions was not yet reached at the end of the treatment, the attempt failed to find any clear connection between the distribution of the sorbed phosphorus and such soil properties as pH, the contents of acid oxalate soluble aluminium and iron, organic carbon, the phosphate sorption capacity and the degree of phosphate saturation. Only in the subsoil samples, 76 per cent of the variation in the net increase in the fluoride-soluble fraction could be explained by the variation on the content of oxalate-soluble aluminium, and in the topsoil samples the oxalate-soluble iron and pH determined 61 per cent of the variation in the net increase in the alkali-soluble phosphorus. The ratio of oxalate-soluble aluminium to iron was more closely correlated with the ratio between the total amounts of fluoride-soluble and alkali-soluble phosphorus than with the ratio between the corresponding sorbed amounts. In the topsoils, it explained 70 per cent of the variation in the former. The distribution of the retained phosphorus did not depend on the soil pH, its content of organic carbon, or its degree of phosphate saturation but there was some tendency to a higher accumulation of alkali-soluble phosphorus compared with the fluoride-soluble forms with an increase in the phosphate sorption capacity of the soil.

scholarly journals Dependence of the phosphate sorption capacity on the aluminium and iron in Finnish soils

1963 ◽  
Vol 35 (4) ◽  
pp. 165-177
Author(s):  
Armi Kaila
Keyword(s):  
Organic Carbon ◽  
Sorption Capacity ◽  
Soil Ph ◽  
Ammonium Oxalate ◽  
Correlation Coefficients ◽  
Fine Sand ◽  
Clay Soils ◽  
Phosphate Sorption ◽  
Soluble Iron ◽  
Soil Groups

An attempt was made to study to what extent the capacity of the more or less acid soils in Finland to sorb phosphate may be explained on the basis of their content of aluminium and iron. The indicator of the phosphate sorption capacity was calculated on the basis of the Freundlich adsorption isotherm according to the procedure proposed by TERÄSVUORI (8). The material consisted of 390 samples from cultivated and virgin soils representing both topsoils and subsoils. The indicator of the phosphate sorption capacity, the coefficient k, varied in the present material from 40 to 1510. The mean values (with the confidence limits at the 95 per cent level) were for the 109 samples of sand and fine sand soils 290 ± 17, for the 103 samples of loam and silt soils 201 ± 24, for the 151 clay soils 308 ± 20, and for the 27 humus soils 236 ± 41. The total linear correlation coefficients between k and the soil pH, and its contents of organic carbon or clay were low or negligible in most of the soil groups. The correlation of k with the content of aluminium extracted by Tamm’s acid ammonium oxalate was fairly close in the clay soils (r = 0.84***), lower in the sand and fine sand soils (r = 0.77***), and in the loam and silt soils, and in the humus soils it was rather poor (r = 0.65*** and 0.63*** resp.). The elimination of the effect of the ammonium oxalate soluble iron decreased the correlation in the two latter groups quite markedly (to 0.32** and 0.37 resp.), while the corresponding decrease in the coefficients for the former groups was less significant (to 0.64*** and 0.75*** resp.). The elimination of the effect of the ammonium oxalate soluble aluminium, on the other hand, decreased the correlation coefficients between k and the ammonium oxalate soluble iron in the sand and fine sand soils from 0.59*** to 0.26**, in the loam and silt soils from 0.73*** to 0.54***, in the clay soils from 0.70*** to 0.51***, and in the humus soils from 0.68*** to 0.49*. The part of variation in k which could be explained on the basis of the variation in the contents of aluminium and iron was different in the different kind of soils. According to the coefficients of determination and the coefficients of multiple determination, the variance in the aluminium content determined 59 per cent of the variance in k in the sand and fine sand soils and 70 per cent in the clay soils; considering also the content of iron increased this part to 61 per cent and 78 per cent, resp. In the loam and silt soils the variation in the iron content explained 53 per cent of the variation in k, in the humus soils this percentage was 47. Considering both aluminium and iron, the proportion of the variance in k which could be explained in these two groups was increased to 60 per cent and 54 per cent, resp. Thus, in addition to the contents of ammonium oxalate soluble iron and aluminium, other factors must be found to explain the variation in the phosphate sorption capacity, particularly in other soil groups than in the clay soils. The soil pH and its content of organic carbon obviously play only a minor role among these ctors.

scholarly journals Calcium, magnesium and potassium in mineral soils from the southern half of Finland

1973 ◽  
Vol 45 (3) ◽  
pp. 254-261
Author(s):  
Armi Kaila
Keyword(s):  
Clay Content ◽  
Total Content ◽  
Fine Sand ◽  
Clay Soils ◽  
Surface Layers ◽  
Surface Soils ◽  
Exchangeable Ca ◽  
Heavy Clay ◽  
Southern Half ◽  
Mineral Soils

210 samples of mineral soils from the southern half of Finland with mainly an acid precambrian bedrock, were analysed for the total contents of Ca, Mg and K, and for the portion of these nutrients which could be exchanged by N NH4OAc (pH 7), dissolved by 0.1 N HCI at room temperature, or released by N HCI at 50° C. The total content of Ca was lowest in samples of heavy clay, 0.78±0.14 % in the surface soils and 0.92±0.10 % in the deeper layers. The mean content in the groups of other soils was at least about 1.1 %. The total content of Mg increased with an increase in the clay content (r = 0.81***). It ranged from 0.6±0.1 % in the sand and fine sand samples to 1.53±0.19 % in the heavy clay soils of the surface layers and to 1.89±0.12 % in those of the deeper layers. Also in the groups of loam and silt soils and of the coarser clay soils, respectively, the Mg content was in the deeper layers higher than in the surface soils. The total content of K also increased with the clay content (r=0.73***) from 1.7±0.1 % in the sand and fine sand soils to 2.74±0.21 % in the heavy clay soils of the surface layers and to 3.10±0.07 % in those of the deeper layers. The portion of exchangeable Ca was relatively high: in the groups of surface soils from more than one tenth to one third of the total amount. The corresponding average amounts released by even the more drastic treatment with acid were not markedly higher. Only a few per cents of total Mg were exchangeable and slightly higher amounts were dissolved by 0.1 N HCI, whereas the treatment with N HCI at 50° C released about half of the total Mg. Exchangeable K and K dissolved by 0,1 N HCI did not exceed 1 % of the total K, except slightly in the heavy clay soils; the average amounts released by N HCI ranged from 5 to 18 % of the total K. The plant availability of these nutrients was discussed.

scholarly journals Exchangeable cations in Finnish soils

1965 ◽  
Vol 37 (2) ◽  
pp. 148-161
Author(s):  
Ulla Marttila
Keyword(s):  
Fine Sand ◽  
Exchange Capacity ◽  
Exchangeable Cations ◽  
Base Saturation ◽  
Clay Soils ◽  
Organic Soils ◽  
Surface Layers ◽  
Mean Values ◽  
Calcium Magnesium ◽  
The Mean

An attempt was made to study the cation exchange capacity, the percentage base saturation and the amounts of the most common cations in the different types and depths of the Finnish soils on the basis of a material of 100 soil samples from various parts of the country. The exchangeable cations were leached from the soil with neutral 1N ammonium acetate. Calcium, magnesium, potassium, sodium and hydrogen were determined and the exchange capacity was calculated as the sum of all these cations. In the different soil types the mean values of the CEC were the following: organic soils 92.1 me per 100 g of soil, non-Litorina clays 28.9 », Litorina clays 27.9 », loam and silt soils 16.9 », sand and fine sand soils 14.5 ». The highest values of the percentage base saturation, on an average 85 % were obtained in the Glacial clay soils and the lowest ones in the organic soils, 34%, and in the Litorina clay soils, 36 %. BS % was generally greater in the deeper than in the surface layers. The contents of clay (

scholarly journals Basic exchangeable cations in Finnish mineral soils

1972 ◽  
Vol 44 (3) ◽  
pp. 164-170
Author(s):  
Armi Kaila
Keyword(s):  
Clay Content ◽  
Fine Sand ◽  
Degree Of Saturation ◽  
Clay Soils ◽  
Exchangeable Ca ◽  
Significant Difference ◽  
Heavy Clay ◽  
The Mean ◽  
Mineral Soils ◽  
Plough Layer

The content of exchangeable Ca, Mg, K and Na replaced by neutral ammonium acetate was determined in 470 samples of mineral soils from various parts of Finland, except from Lapland. The amount of all these cations tended to increase with an increase in the clay content, but variation within each textural class was large, and the ranges usually overlapped those of the other classes. The higher acidity of virgin surface soils was connected with a lower average degree of saturation by Ca as compared with the corresponding textural classes of cultivated soils. No significant difference in the respective contents of other cations was detected. The samples of various textural groups from deeper layers were usually poorer in exchangeable Ca and K than the corresponding groups of plough layer. The mean content of exchangeable Mg was equal or even higher in the samples from deeper layers than in the samples from plough layer, except in the group of sand soils. The percentage of Mg of the effective CEC increased, as an average, from 9 in the sand and fine sand soils of plough layer to 30 in the heavy clay soils; in the heavy clay soils from deeper layers its mean value was 38 ± 4 %. In the samples of plough layer, the mean ratio of Ca to Mg in sand and fine sand soils was about 9, in silt and loam soils about 6, in the coarser clay soils about 4, and in heavy clay about 2.

scholarly journals Sulphate sorption by Finnish mineral soils

1987 ◽  
Vol 59 (1) ◽  
pp. 41-46
Author(s):  
Markku Yli-Halla
Keyword(s):  
Soil Properties ◽  
Soil Ph ◽  
Negative Correlation ◽  
Ammonium Acetate ◽  
Phosphorus Fertilization ◽  
Phosphate Sorption ◽  
Soluble Phosphorus ◽  
Soil Component ◽  
Phosphorus Status ◽  
Mineral Soils

Sulphate sorption by 38 Finnish cultivated mineral soils was determined and its correlation with soil properties was studied. Sulphate sorption was correlated with soil pH (r =—0.46**) and with phosphate sorption (r =0.69***). With increasing soil pH, sulphate sorption decreased in relation to phosphate sorption. Phosphorus status was decisive in explaining the sulphate sorption of the soils. Even if both anions are sorbed by the same soil component (amorphous Al compounds), the sites are not available for sulphate if they are already occupied by phosphate. Sulphate sorption was negligible in soils very rich in easily soluble phosphorus. This was reflected in a close negative correlation between sulphate sorption and acid ammonium acetate (pH 4.65) extractable phosphorus (r =—0.70***). During the last few decades, phosphorus fertilization has increased the amount of easily soluble phosphorus in Finnish fields, which obviously has decreased the capacity of the soils to retain sulphate.

scholarly journals Fractions of inorganic phosphorus in Finnish mineral soils

1964 ◽  
Vol 36 (1) ◽  
pp. 1-13 ◽  
Author(s):  
Armi Kaila
Keyword(s):  
Organic Phosphorus ◽  
Ammonium Oxalate ◽  
Fine Sand ◽  
Inorganic Phosphorus ◽  
Phosphorus Fraction ◽  
Surface Samples ◽  
Low Degree ◽  
Soluble Phosphorus ◽  
The Difference ◽  
Mineral Soils

Inorganic phosphorus in 363 samples of Finnish mineral soils was fractionated by the procedure of CHANG and JACKSON. The average content of total inorganic phosphorus determined as the difference of the total phosphorus and organic phosphorus tended to increase from sand to clay soils. The sand and fine sand soils appeared to be richer in fluoride-soluble phosphorus but poorer in acid-soluble phosphorus than the other groups of soils. The part of phosphorus extracted by alkali seemed to be almost independent on the soil texture. In about 60 per cent of the samples the acid-soluble phosphorus was the dominant inorganic phosphorus fraction, in spite of the often high acidity of the soil. This, in connection with the rather low content of reductant soluble phosphorus, was taken to indicate the relatively low degree of weathering in these soils. The higher contents of fluoride-soluble and alkali-soluble phosphorus in the surface samples of the cultivated soils as compared with the corresponding kind of virgin soils or soils from the deeper layers may be mainly attributed to the application of phosphorus fertilizers and to a somewhat higher degree of weathering. The soil pH did not seem to play any important role among the factors related to the distribution of inorganic phosphorus into various fractions in the present material. This was particularly true in the cultivated surface soils. It is likely, that in our soils the variation in the contents of active iron and aluminium will to a higher degree than pH explain the variation in the fractions of alkali-soluble and fuoride-soluble phosphorus. The relatively high content of the latter fraction in the sand and fine sand soils as compared with the soils of the finer texture could be related to the higher ratio of ammonium oxalate soluble aluminium to iron in the former soils.

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

1967 ◽  
Vol 39 (1) ◽  
pp. 5-13 ◽  
Author(s):  
Armi Kaila
Keyword(s):  
Soluble Fraction ◽  
Calcium Phosphates ◽  
Soil Phosphorus ◽  
Inorganic Phosphorus ◽  
Soluble Form ◽  
Prolonged Incubation ◽  
Phosphate Retention ◽  
Soluble Phosphorus ◽  
Mineral Soils ◽  
Small Parts

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.

The distribution of phosphorus in forest and savannah soils of the Gold Coast and its agricultural significance

1957 ◽  
Vol 49 (2) ◽  
pp. 141-159 ◽  
Author(s):  
P. H. Nye ◽  
M. H. Bertheux
Keyword(s):  
Organic Carbon ◽  
Total Phosphorus ◽  
Organic Phosphorus ◽  
Gold Coast ◽  
Residual Fraction ◽  
Soluble Phosphate ◽  
Composite Surface ◽  
Surface Samples ◽  
The World ◽  
Soluble Phosphorus

The amount of phosphorus in composite surface samples and profile samples from a range of agriculturally important soils in the forest and savannah regions of the Gold Coast has been determined. The total phosphorus in each sample has been divided into an acid-soluble, an inorganic alkali-soluble, an organic and a residual fraction. On the surface samples these fractions, together with the soil pH, organic carbon and Bray ‘quick-test’ available phosphorus, have been related to superphosphate responses in the savannah region. The following conclusions have been reached:Surface samplesThe total phosphorus in the soils is low by comparison with other parts of the world, but its distribution among the soil fractions is normal for slightly acid soils.Soils developed over basic rocks have more total phosphorus, and a lower proportion of acid-soluble phosphorus than soils over quartzose rocks.Forest soils have more total phosphorus and more phosphorus in each of the fractions than savannah soils.The organic phosphorus content is closely related to the organic carbon content. The C/P ratio averages 233 in forest and 247 in savannah, and this is considerably higher than the world average. The N/P ratio of 21·6 in forest and 19·5 in savannah is similarly high.The C/P ratio, unlike the C/N ratio, is not reduced when long-rested savannah soils are cropped.Soluble phosphate applied in permanent fertilizer trials is found in the acid-soluble, the alkali-soluble and organic fractions. In comparison with the amounts of those fractions already present, the acidsoluble fraction increases most and the organic fraction least.Profile samplesIn thoroughly leached soils the acid-soluble phosphate decreases sharply, and the alkali-soluble inorganic phosphate rather more slowly with depth. In the forest total phosphorus is greatest in the surface, but in the savannah there is no consistent change with depth. The incompletely leached profiles differ in showing a sharp rise in the acid-soluble phosphorus and the total phosphorus in the subsoil. The level of organic phosphorus falls less than expected down the profile, and the C/P ratio, like the C/N ratio, decreases in the subsoil.

EFFICIENCY OF PHOSPHATIC FERTILIZERS OF VARYING WATER-SOLUBILITY

1961 ◽  
Vol 41 (1) ◽  
pp. 68-80 ◽  
Author(s):  
J. Hagin ◽  
J. Berkovits
Keyword(s):  
Rock Phosphate ◽  
Water Solubility ◽  
Soluble Fraction ◽  
Water Soluble ◽  
Soluble Phosphate ◽  
Phosphate Availability ◽  
Soluble Phosphorus ◽  
Phosphatic Fertilizers

Three fertilizers containing various amounts of citrate- and water-soluble phosphates were compared with superphosphate and rock phosphate in field and greenhouse experiments.Yield curves and equations were calculated and drawn and, from these, availability coefficients were calculated.The phosphate availability of the fertilizers was reduced as the relative amount of water-soluble phosphate they contained was reduced. However, in fertilizers that contained a relatively large amount of water-soluble phosphorus, the citrate-soluble fraction was partly available.

scholarly journals Sorption capacity of phosphate in mineral soils: II Dependence of sorption capacity on soil properties

1990 ◽  
Vol 62 (1) ◽  
pp. 9-15
Author(s):  
Raina Niskanen
Keyword(s):  
Soil Properties ◽  
Sorption Capacity ◽  
Mineral Soil ◽  
Clay Content ◽  
Organic C ◽  
Phosphate Sorption ◽  
P Sorption ◽  
P Sorption Capacity ◽  
Mineral Soils ◽  
Extractable Al

The dependence of the indicator of phosphate sorption capacity on extractable Al and Fe and other soil properties was studied in a material consisting of 102 mineral soil samples. The sum of P adsorbed on soil during two days from a solution containing P 5 mmol/l and P extracted by 0.02 M EDTA (pH 5.3) as an estimate of the initial P content in the soil was used as the indicator of P sorption capacity. In clay and silt soils (n = 51), the Al and Fe extracted by 0.05 M oxalate (pH 2.9) together with the organic C content explained 85 %, the Al and Fe extracted by 0.05 M K4P2O7 (pH 10) together with the clay content 87 %, the Al and Fe extracted by 0.02 M EDTA (pH 5.3) 91 %, and the Al extracted by 1 M CH3COONH4 (pH 4.8) together with the organic C and clay contents 78 % of the variation of the indicator of phosphate sorption capacity. In coarse soils (n = 51), the variation of the indicator was explained well only by oxalate-extractable metals, which together with soil pH and clay content explained 80 % of the variation. Extractable Al was generally the most important explainer of variation. The results suggest that forms of extractable Al and Fe explaining the variation of the indicator of P sorption capacity in clay and silt soils are partially different from those in coarse soils.

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