scholarly journals Aluminium and acidity in Finnish soils

1971 ◽  
Vol 43 (1) ◽  
pp. 11-19
Author(s):  
Armi Kaila

In the present study an attempt was made to study by statistical methods the proportion of Al of the exchange acidity of 298 soil samples of various kind, and to what extent the titratable nonexchangeable acidity in these soils is connected with Al, when Al soluble in Tamm’s acid oxalate was used as its indicator. Unbuffered N KCI replaced Al only from soil samples with a pH less than 5.3 in 0.01 M CaCl2 . In this part of the material, Al corresponded, on the average, to one third of the exchange acidity of mineral soil samples, and to 16 per cent of that of organic soils. The amount of Al was usually the higher the lower the soil pH, but the correlation was close only in the group of clay soils. Titratable nonexchangeable acidity was estimated as the difference of the amount of acidity neutralized at pH 8.2 and the corresponding amount of exchange acidity replaced by unbuffered KCI. In 100 clay soil samples it was, on the average, 12.0 ± 1.3 me/100 g, in 42 samples of silt and loam soils 8.8 ± 1.8 me/100 g, in 99 sandy soils 8.9 ± 1.1 me/100 g and in 57 organic soils 49.1 ± 6.8 me/100 g. There was no correlation between titratable nonexchangeable acidity and the clay content within various soil groups. In the clay soils exalate soluble Al alone explained 78.3 %, in the silt and loam soils 59.8 %, in the sandy soils 6.5 %, and in the organic soils 0.6 % of the variation in titratable nonexchangeable acidity. Taking into account the content of organic C increased the rate of explanation only to 82.1 % in clay soils, to 84.1 % in silt and loam soils, to 83,1 % in sandy soils, and to 63.7 % in the organic soils. Further, adding the soil pH increased the rate of explanation 5.8 to 9.6 per cent units in various soil groups, but considering of oxalate soluble Fe did no more distinctly increase the part of variation explained, except in the organic soils. Regression equations were calculated for the relationship of these variables. According to the partial correlation coefficients and to the β-coefficients, the relative importance of oxalate soluble Al in explaining the variation in titratable nonexchangeable acidity was in the clay soils higher than even that of organic C content, but in the other mineral soil groups it was less important than both C content and pH; in the organic soils even oxalate soluble Fe appeared to be slightly more important.

1971 ◽  
Vol 43 (3) ◽  
pp. 178-186
Author(s):  
Armi Kaila

Effective CEC of 230 mineral soil samples was estimated as sum of (Ca + Mg) and (AI + H) displaced by N KCI. The mean values as me/100 g of soil were, in the surface samples, 15.9 ± 2.0 in 46 clay soils, 8.9 ± 1.3 in 21 silt and loam soils, and 8.3 ± 1.1 in 39 sandy soils. In samples from the deeper layers the corresponding means were 16.3 ± 2.3 in 54 clay soils, 5.6 ± 0.9 in 21 silt and loam soils, and 2.5 ± 0.5 in 49 sandy soils. In surface samples of clay soils the mean effective CEC was about two thirds, in sandy soils of deeper layers about one third, and in all other groups about one half of the corresponding average potential CEC determined by neutral ammonium acetate. In the total material in which clay content ranged from 0 to 95%, organic C from 0.1 to 8.7 %, soil pH from 3.3 to 7.5, and oxalate soluble Al from 1.4 to 47.9 mmol/100 g, the »effective CEC» depended mostly on clay content: the partial correlation coefficient r = 0.90***, and the standard partial regression coefficient β = 0.84. The corresponding coefficients for the relationship between the »effective CEC» and the content of organic C were r = 0.55*** and β = 0.29, soil pH r = 0.35*** and β = 0.16, and oxalate soluble Al r = –0.13 and β = –0.06. The positive effect of liming on effective CEC, particularly, in coarser textured acid soils high in organic matter was emphasized.


1986 ◽  
Vol 58 (2) ◽  
pp. 43-46
Author(s):  
Helinä Hartikainen

The base-neutralizing capacity, BMC7 (OH- as meq kg-1 needed to raise soil pH to 7), was determined graphically from curves obtained in KOH titration (at a constant ionic strength of I = 0.1). In 84 soil samples, BMC7 amounted to 0—316 meq kg-1, being highest in the heavy clay soils and lowest in the non-clay soils. In different textural groups, BMC7 seemed most markedly to be dependent on the initial soil pH, followed by organic C or oxalate soluble Al, in the coarser clays also on clay content. The results evidence that in determination of lime requirement, attention should be paid to the capacity of soil acidity. In routine soil testing, detailed lime recommendations for various soil types are needed.


2013 ◽  
Vol 59 (1) ◽  
pp. 38-43
Author(s):  
Jana Bútorová

Abstract According to national and international laboratory methods, the density of soil samples is determined by pycnometer in heated samples crushed by ultrasound. In mineral soils, the elementary unit of density is represented by a mineral grain of quartz, granite, andesite, etc. On the other hand, in organic soils, the elementary unit is represented by a leaf (or just a part of it), needles, stems and roots. Heating of the mineral grain causes its release from the soil aggregate. Organic parts of the soil are losing air vacuoles by heat treatment while in the same time, carbohydrates, proteins, oils and resins create new chemicals which are heavier than water. That is a reason why density determination of litter subhorizons in forest soils needs to have different rules in comparison with mineral soil samples. Samples with more than 50 volume per cent of organic matter are not treated by heat and do not decompose. In case of high mineral soil content, mineral parts are removed from the sample and their density is determined. The final density is based on mathematically processed data.


1985 ◽  
Vol 57 (4) ◽  
pp. 279-283
Author(s):  
Helinä Hartikainen

The acid-neutralizing capacity (ANC) was determined graphically from curves obtained in HCI titration (at a constant ionic strength I = 0.1) and was expressed as a quantity of acid (meq kg-1) needed to reduce the soil pH to 3.8. The relationship between ANC3.8 g and soil characteristics was studied statistically. In 84 soil samples, ANC3.8 ranged from 12 to 184 meq kg-1. The average ANC3.8 was highest in the heavy clay soils and lowest in the non-clay soils, but the differences between the various textural soil groups were not significant. In all soil groups the initial pHCaCl2 was relatively the most important factor explaining the variation in ANC3.8. Organic C was also a significant variable; this was considered to indicate the importance of cation exchange reactions of organic matter in acid-buffering. With the exception of heavy clay soils, oxalate-soluble Al significantly explained the variation in ANC3.8, suggesting that dissolution of Al hydroxides acted as a sink for H+ ions and contributed to the neutralizing capacity at the reference pH of 3.8.


2007 ◽  
Vol 37 (6) ◽  
pp. 1118-1133 ◽  
Author(s):  
Rock Ouimet ◽  
Sylvie Tremblay ◽  
Catherine Périé ◽  
Guy Prégent

We assessed the organic C stocks and inferred their changes in vegetation biomass, forest floor, and soil using a 50 year chronosequence of red pine ( Pinus resinosa Ait.) plantations established on postagricultural fields in southern Quebec, Canada. The data come from soil and tree field surveys carried out in the 1970s in 348 sites. Organic C concentrations were usually measured in three major mineral soil horizons; for the remaining soil horizons, they were estimated using pedotransfer functions. The effect of soil order, drainage, and texture was analysed. Over 22 years, organic C accumulation rates (Mg C·ha–1·year–1) were 1.66 ± 0.03 in vegetation biomass, 0.56 ± 0.07 in forest floor, 0.86 ± 0.47 in loamy soils (0–100 cm), and  –0.18 ± 0.24 in sandy soils (0–100 cm). The greater rate of C accumulation in loamy soils was due to the contribution of the 30–100 cm subsoil layer. The overall net accumulation of organic C in these plantation ecosystems was estimated to 51.4 ± 4.8 Mg C·ha–1 at 22 years. Soils of these plantations acted as a C sink in the first two decades, particularly in loamy soils compared with sandy soils, with no major differences among soil order or drainage.


1981 ◽  
Vol 61 (4) ◽  
pp. 577-579 ◽  
Author(s):  
W. VAN LIEROP

Regression equations were derived for converting pH values of organic soils determined by five procedures. Data were obtained by measuring the pH of 30 soils using the following volumetric ratios and solutions: 1:1, soil to water; 1:2 and 1:4, soil to 0.01M CaCl2; and 1:2 and 1:4 soil to 1N KCl. Average pH values measured in 0.01M CaCl2 and 1N KCl were 0.44 and 0.70 pH units lower than those measured in water (pH 5.21). Converting data by merely adding or subtracting the average difference between methods was not as accurate as using appropriate regression equations. These equations are provided in the text and indicated that differences between soil pH values measured by different procedures increased as soil pH increased. Similar pH values were found with the 1:2 and 1:4 soil to 0.1M CaCl2 solution ratios, though a small dilution effect was observed when 1N KCl was used at these ratios.


1963 ◽  
Vol 35 (4) ◽  
pp. 165-177
Author(s):  
Armi Kaila

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.


1974 ◽  
Vol 54 (4) ◽  
pp. 379-385 ◽  
Author(s):  
T. G. ALEXANDER ◽  
J. A. ROBERTSON

Soil samples from virgin profiles of Solonetzic and geographically associated Chernozemic series along with Ap horizons of Solonetzic and Chernozemic soils were taken. Soil pH, organic C, oxalate-extractable Al and Fe, inorganic P forms, organic and total P, and extractable P by NH4F + H3SO4 and NaHCO3 methods were determined. On the average, Solonetzic sola had higher contents of oxalate-extractable Al and Fe, Fe-P, and lower levels of Ca-P than do their associated Chernozemic sola. There was not a clear difference in Al-P contents between the sola of the two Orders. Ap samples from Solonetzic soils had twice the amount of NH4F + H2SO4- and NaHCO3-extractable P found in the Chernozemic ones. The higher levels of extractable P in the Solonetzic than in the Chernozemic Ap samples could be explained by the higher contents of Al-P and Fe-P in the former. The high acidity in the upper sola of Solonetzic soils, indicative of intense weathering conditions, apparently has resulted in relatively high contents of oxalate-extractable Al and Fe, and these probably account for the higher levels of Al-P and Fe-P and lower levels of Ca-P in the Solonetzic than in the Chernozemic soils.


1965 ◽  
Vol 37 (1) ◽  
pp. 51-60
Author(s):  
Ritva Ryti

In the present paper the routine determination of soil pH in the laboratory was studied using a material of 15 soil samples of various kind and in addition, two larger soil groups, consisting of 80 and 406 samples respectively. In comparing the pH values determined in water and in 0.01 M CaCl2 suspensions, the latter proved to be almost independent of the soil/liquid ratio between 1: 2.5 and 1: 10, that markedly affected the pHH2O values. The change with time from the pH values measured after the first hour showed less variation in CaCl2 suspensions than in water suspensions; the constancy observed in pHCaCl2 values indicating that a relatively short equilibration period of 1—2 hours would be sufficient. To sum up these results, the use of 0.01 M CaCl2 would mean easy and accurate measurements well suited to mass pH determinations. A linear relationship and a highly significant positive correlation was found between pHH2O and pHCaCl2 values in a material of 406 soil samples. The difference between the two values, which largely depends on the soils’ own salt content, ranged from 0 to 1.1 pH units, with the mean difference of 0.49. Therefore, the suggested use of a constant correction factor to bring the pHCaCl2 values to the level of the pH measured in water, is not recommendable. The main advantage of using 0.01 M CaCl2 would be the concealing of differences in salt content of a soil. The use of pHCaCl2 values would also offer new ways for getting more information about a soil’s exchange capacities, as it provides the center point for TERÄSVUORI’s (13) soil curve.


2021 ◽  
Vol 7 (1) ◽  
pp. 12-20
Author(s):  
Asif Ahmed Ratul ◽  
Tahsina Sharmin Hoque ◽  
Md Rafiqul Islam ◽  
Md Anamul Hoque

Soil reaction is an important issue that adversely affects soil fertility and crop productivity. Twenty five representative soil samples from farmers’ fields of Ramchandrakura, Bishgiripar, Andharupara and Nayabil villages of Nalitabari upazila under Sherpur district (AEZ 22-Northern and Eastern Piedmont Plains) and twenty soil samples from farmers’ fields of Bakta, Nishchintopur, Boril and Kaladaho villages of Fulbaria upazila under Mymensingh district (AEZ 28-Madhupur Tract) were collected and analyzed to study the physico-chemical properties of acid soils. Among 45 samples, 13 were sandy loam, 17 were silt loam, 10 were loam, 2 were clay loam and 3 were loamy sand in texture. Soil pH was very strongly acidic to strongly acidic. The soil pH of AEZ 22 varied from 3.81 to 4.78 and that of AEZ 28 varied from 3.96 to 5.11. The organic C of Nalitabari soil varied from 0.50 to 1.35% and that of Fulbaria soils ranged from 0.50 to 1.27% showing low to medium status. The status of nutrient elements viz. N, P, K and S in most of the samples was very low or very low to medium. Total N contents of AEZ 22 varied from 0.06 to 0.14% and that of AEZ 28 varied from 0.07 to 0.16%. Available P in soils of AEZ 22 varied from 3.25 to 26.45 ppm and that in soils of AEZ 28 ranged from 2.45 to 16.62 ppm. Exchangeable K in AEZ 22 soils varied from 15.13 to 92.41 ppm and that in AEZ 28 soils varied from 16.09 to 98.41 ppm. Available S in AEZ 22 soils varied from 1.68 to 33.70 ppm and that in AEZ 28 soils from 3.95 to 27.52 ppm. Therefore, these acid soils should be amended with liming materials and fertilized with inorganic fertilizers and organic manures for successful crop production. Asian J. Med. Biol. Res. March 2021, 7(1): 12-20


Sign in / Sign up

Export Citation Format

Share Document