THE EXTRACTION OF EXCHANGEABLE CATIONS FROM SOILS

1965 ◽  
Vol 45 (3) ◽  
pp. 311-322 ◽  
Author(s):  
J. S. Clark
Keyword(s):  
Soil Ph ◽  
Experimental Error ◽  
Colorimetric Method ◽  
Soil Samples ◽  
Exchangeable Cations ◽  
Base Saturation ◽  
Ion Concentrations ◽  
Ph Values ◽  
Exchangeable Al ◽  
Wyoming Bentonite

A study was made of techniques for the measurement of soil pH and corrected lime potential and for the extraction of exchangeable cations from soils. The experiments showed that in order to obtain stable and reliable pH values and ion concentrations it was necessary to equilibrate the soil samples in CaCl2 (0.005 to 0.02 M) for 4 to 5 days. After the soil was washed twice with water, the exchangeable cations were extracted from the equilibrated samples by shaking for 16 to 24 hours with 100 ml 2 N NaCl for 0.5 to 2.5 meq of exchangeable cations. In order to obtain reliable values for exchangeable Al with the soils studied, it was necessary to use a colorimetric method instead of titration with NaOH. When these precautions were observed the relation between corrected lime potential and percent base saturation for a number of soils agreed within reasonable experimental error with the theoretical one obtained for Wyoming bentonite.

scholarly journals A survey of the pH status and related fertility factors of sugarcane fields of Puerto Rico

1969 ◽  
Vol 75 (3) ◽  
pp. 213-222 ◽  
Author(s):  
Antonio Vélez-Ramos ◽  
Miguel A. Muñoz
Keyword(s):  
Puerto Rico ◽  
Soil Ph ◽  
Field Survey ◽  
Soil Samples ◽  
Base Saturation ◽  
Soil Factors ◽  
Ph Values ◽  
Exchangeable Al ◽  
Sugarcane Yield ◽  
Production Areas

A field survey was initiated in the main sugarcane production areas of Puerto Rico to determine the pH status of sugarcane soils and those specific soil factors that influence growth and development, such as exchangeable cations, percentage base saturation (% BS) and lime requirement. Soil samples from Coloso, Plata, Arecibo, Humacao, Yabucoa and Eureka areas were analyzed for pH, available P, Fe and Mn; exchangeable K, Ca, Mg and Al; percentage base saturation and lime requirements. Soil pH ranged from as low as 3.2 to a high of 8.1. Sixty-eight percent of the soil samples analyzed showed pH values below 5.5. The lowest soil pH values were observed in the Eureka area and the highest in Arecibo, whereas in the Coloso, Plata, Humacao and Yabucoa areas pH values were intermediate with readings between 4 and 5 as an average. Eighty percent of the soil samples from Plata, 40.0% of those from Eureka and 40.5% of those from Coloso had pH values below 4.5. All soil samples collected in Humacao and Yabucoa (except one) showed pH values below 5.5. No definite trend was observed when sugarcane yield per acre and soil pH for the Yabucoa-Humacao area were compared. In general, P and K were low in all regions sampled, whereas Ca and Mg values were higher in the Coloso than in the Yabucoa-Humacao regions. Soils from the Coloso region showed higher levels of exchangeable Al and higher percentages of Al saturation than soils from the Yabucoa-Humacao region. This fact, together with a lower % BS should aggravate acidity problems in the Coloso region. Percentage base saturation was good at the higher pH readings.

scholarly journals Clay dispersion and loss in Oxisol treated with different concentrations of limestone

2017 ◽  
Vol 38 (6) ◽  
pp. 3907 ◽  
Author(s):  
Wesley Machado ◽  
Thadeu Rodrigues de Melo ◽  
João Tavares Filho
Keyword(s):  
Soil Ph ◽  
Dispersion Analysis ◽  
Test Tube ◽  
Soil Samples ◽  
Base Saturation ◽  
Clay Dispersion ◽  
Clay Concentration ◽  
Significant Change

The addition of limestone to the soil may cause clay dispersion and loss. In this study, we aimed to estimate clay dispersion and loss in Oxisol incubated with different concentrations of limestone. To this end, soil samples were collected from a depth of 0.0-0.20 m, treated with limestone at a concentration of 1.46 Mg ha-1 or 2.73 Mg ha-1 to raise base saturation to 60% and 70%, respectively, and incubated for 12 months under greenhouse conditions. Clay dispersion analysis was conducted monthly using the test tube method. The results showed that clay dispersion increased with soil pH and time after limestone application. However, no significant change in clay concentration was identified in the control (no limestone application). At 60% base saturation, clay loss was first observed to be significantly higher than that of the control at 4 months after application and reached a maximum at 9 months after application. At 70% base saturation, clay loss was also first observed to be significantly higher than that of the control at 4 months after application and reached a maximum at 6 months after application. Overall, our data revealed that clay dispersion due to limestone application was approximately 16 g kg-1 over a period of 12 months and increased with the increasing concentrations of Ca and Mg.

REACTIONS OF IRON HYDROUS OXIDE WITH WYOMING BENTONITE

1968 ◽  
Vol 48 (2) ◽  
pp. 173-183 ◽  
Author(s):  
J. S. Clark ◽  
W. E. Nichol
Keyword(s):  
Exchange Capacity ◽  
Oxide System ◽  
Low Ph ◽  
Exchangeable Cations ◽  
Hydrous Oxide ◽  
Excess Iron ◽  
Ph Values ◽  
Hydrous Oxides ◽  
Fe Complexes ◽  
Wyoming Bentonite

Iron hydrous oxides were precipitated in Wyoming bentonite suspensions. With these preparations, close agreement was obtained between experimental corrected lime-potential and base saturation values and the titration curve calculated for the Wyoming bentonite-Fe hydrous oxide system, if (a) the exchangeable cations were extracted with NaNO3, (b) titration was used to determine the sum of trivalent ions extracted and (c) Fe and Al were considered to be equivalent exchangeable cations. The sum of cations extracted with NaNO3, therefore, was used as a measure of the effective cation exchange capacity (CEC) of the clay preparations containing excess iron oxides.The effective CEC's were low after short reaction intervals, but increased rapidly with time and were approaching the original CEC of the clay. The extent to which the CEC may have been reduced initially could not be determined because charged polynuclear hydroxy Fe complexes were present on the exchange complex. The fact that these complexes disappeared by 2 weeks and that the CEC values were approaching the original value clearly show that the Fe hydrous oxide clay complexes were not stable. Because of this and the low pH values at which the complexes were formed, the existence of Fe hydrous oxide-clay complexes in most natural soils was considered unlikely.

scholarly journals Response of Corn to Acidity Factors in Eight Tropical Soils

1969 ◽  
Vol 58 (1) ◽  
pp. 59-77
Author(s):  
Fernando Abruña ◽  
Raúl Pérez-Escolar ◽  
José Vicente-Chandler ◽  
Robert W. Pearson ◽  
Servando Silva
Keyword(s):  
Soil Ph ◽  
Ammonium Acetate ◽  
Aluminum Content ◽  
Calcium Content ◽  
Tropical Soils ◽  
Base Saturation ◽  
Base Content ◽  
Ph Values ◽  
Exchangeable Aluminum ◽  
Close Relationship

The effect of soil acidity factors was determined on yields and foliar composition of corn grown on Ultisols and Oxisols typical of the Humid Tropics. Soil pH values increased from about 3.8 with a base saturation of around 20 percent to about pH 5 with a base saturation of around 70 percent based on cation exchange capacities determined with neutral ammonium acetate. The low pH values in relation to exchangeable base contents are explained by the presence of free salts. The level of aluminum saturation of the soil based on exchange capacities as determined with ammonium acetate decreased from 40-percent at about pH 3.9 to 0 at about pH 5.2. The Ultisols had a high content of exchangeable aluminum when acid but the more weathered Oxisols contained little aluminum. A very close relationship exists between exchangeable base (Ca + Mg) and aluminum values based on total exchange capacities determined either with ammonium acetate at pH 7.0 or by the sum of cations at a given pH permitting conversion of one value to another. Corn responded strongly to liming particularly on the Ultisols which had high exchangeable aluminum content when acid. Calcium content of the corn leaves increased with soil base content and with yields but foliar composition was not otherwise affected by liming. Corn yields increased with pH to about 5.2 at which pH level these soils contained essentially no exchangeable aluminum, with exchangeable base content as determined with ammonium acetate to about the 70-percent saturation level, and with decreasing exchangeable aluminum in the soil to essentially 0. Soil pH, exchangeable base, and exchangeable aluminum content were effective criteria for liming these soils.

Selective isolation and distribution ofActinobisporastrains in soil

2000 ◽  
Vol 46 (8) ◽  
pp. 708-715 ◽  
Author(s):  
Shin-ichi Suzuki ◽  
Toru Okuda ◽  
Saburo Komatsubara
Keyword(s):  
Heat Treatment ◽  
Soil Ph ◽  
Soil Samples ◽  
Selective Isolation ◽  
Enrichment Method ◽  
Dry Heat ◽  
Ph Values ◽  
The World ◽  
Neutral Soil ◽  
Dry Heat Treatment

A simplified enrichment method for selective isolation of Actinobispora strains from soil is described. Actinobispora spores were tolerant to dry-heat treatment at 110°C for 15 min. Actinobispora was more resistant to 1 µg/mL leucomycin, 1 µg/mL novobiocin, and 0.5 µg/mL tunicamycin than Streptomyces dominant in soil, which prevents selective isolation of Actinobispora. Percentages of Actinobispora colonies on the isolation plate were increased by addition of antibiotics and dry-heat treatment of the soil samples. By combining the techniques described above, this genus was isolated from 105 out of 574 soil samples (18% of the samples tested). It was recovered from the soil samples with pH values ranging 5.0 to 8.9, and 78% of strains were isolated from neutral soil (pH 6.0-8.0). A number of Actinobispora strains were isolated from various soils around the world. Actinobispora strains are widely distributed in the world at relatively high frequency.Key words: Actinobispora, gellan gum, selective isolation, actinomycete, distribution.

scholarly journals Reduction of exchangeable calcium and magnesium in soil with increasing pH

2001 ◽  
Vol 44 (2) ◽  
pp. 149-153 ◽  
Author(s):  
Mário Miyazawa ◽  
Marcos A. Pavan ◽  
Cláudio O. Ziglio ◽  
Júlio C. Franchini
Keyword(s):  
Chemical Reactions ◽  
Soil Ph ◽  
Laboratory Study ◽  
Soil Samples ◽  
Exchangeable Calcium ◽  
Exchangeable Ca ◽  
Exchangeable Al ◽  
Naoh Solution ◽  
Synthetic Solution ◽  
Calcium And Magnesium

A laboratory study was conducted with soil samples and synthetic solutions to investigate possible mechanisms related with reduction in KCl exchangeable Ca and Mg with increasing pH. Increasing soil pH over 5.3 with CaCO3 added to the soil and with NaOH solution added to soil/KCl suspension increased adsorptions of Ca and Mg. The reduction of Mg was greater than Ca and was related to the concentration of soil exchangeable Al. The decreases of soluble Ca and Mg following addition of Al in synthetic solution were at pH > 7.5. The isomorphic coprecipitation reaction with Al compounds may be the most possible mechanism responsible for the decrease of exchangeable Ca and Mg with increasing pH. Possible chemical reactions are presented.

Accumulation and distribution of toxic and potentially toxic elements in potato on different types of soil

2020 ◽  
Author(s):  
Jelena Popović-Djordjević ◽  
Zoran Broćić ◽  
Mirjana Kresović ◽  
Jelena Mutić
Keyword(s):  
Trace Elements ◽  
Soil Ph ◽  
Toxic Elements ◽  
Potato Production ◽  
Soil Samples ◽  
The Other ◽  
Emission Spectrometry ◽  
The Core ◽  
Ph Values ◽  
Other Hand

<p>Potato is currently the third most significant crop culture in the world, with the production of over 388 million tons in 2016. This crop is present on the tables of Serbian consumers throughout the year because of the tradition and its affordable price. Serbia has relatively good climatic conditions for potato production, which are defined by the temperature regime and the amount and frequency of precipitation. The nutritive value of the potato is mainly attributed to the chemical composition of the tuber. The element composition of tubers depends on many factors, such as: genotype, developmental phase of the plant, agroecological conditions, chemical properties of soil, fertilization and irrigation. On the other hand, geochemical origin of trace elements in the soil, the intensive agriculture production, use of contaminated soil and irrigation water may increase their toxic levels in tubers.</p><p> Potato tubers of five varieties were produced on commercial farms at two locations in Western Serbia (Guča and Sjenica), with favorable agroecological conditions for potato production. Tuber samples of studied varieties from each location were collected at the end of growing seasons at the stage of physiological maturity. Soil samples were collected from several sites at each production location at the depth of 0–30 cm. Basic agrochemical properties of the soil samples were determined. Content of toxic (As, Cd, Pb) and potentially toxic (Al, Ba, Ni, V) elements in fresh tubers (peel and core) and soil samples was established by inductively coupled plasma–optical emission spectrometry (ICP–OES). Bioaccumulation factor (BAF) of each studied element, as the ratio between its content in the peel and in the core of the tuber and the soil, was calculated.</p><p> According to pH values, 4.77 and 6.80, soils were clasified as very acidic (Guča location) and slightly acidic (Sjenica location), respectively. Content of studied trace elements in soils, with the exception of Ni, was within the allowable limits. Tuber peel of all studied varieties grown on both soil types was characterized with the higher content of Cd, Al, Ba and Ni, compared to the relevant core. Consenquently, the higher values of BAF were observed in the peel of tubers. Average values of BAF for the studied elements in the peel for both soil pH values 4.77 and 6.80 (Guča and Sjenica, respectively) were in the following order: Cd>Ba>Pb>As>Ni>Al=V. On the other hand, average BAF values for the core of the tuber samples were in a slightly different order, depending on the soil pH; Cd>Pb>As>Ba>Ni>Al=V (pH 4.77) and Cd>Pb>As>Ba=Ni>V (pH 6.80). The highest/lowest BAFs were calculated for Cd (0.339) in the peel and Al (0.0002) in the core, respectively. Content of As and Cd did not exeed the maximum allowed concentrations set by the national and European Union regulations, but it should be pointed out that Cd content was close to the upper limit. Also, it was noticed that the content of Pb exceeded the safe limit set for these elements according to both regulations.</p><p>Keywords: potato tuber, soil, toxic elements, ICP</p><p>Acknowledgement: This work was supported by the Ministry of Education, Science and Technological Development of the Republic of Serbia (Research grant No. 46009).</p>

WATER-SOLUBLE AND EXCHANGEABLE ALUMINUM IN ACID SOILS AS AFFECTED BY LIMING AND FERTILIZATION

1967 ◽  
Vol 47 (3) ◽  
pp. 203-210 ◽  
Author(s):  
L. B. MacLeod ◽  
L. P. Jackson
Keyword(s):  
Soil Ph ◽  
Surface Soil ◽  
Acid Soils ◽  
Water Soluble ◽  
Ph Values ◽  
Exchangeable Al ◽  
Exchangeable Aluminum ◽  
High Fertilization ◽  
Surface Soil Ph ◽  
Representative Samples

The concentration of water-soluble and exchangeable aluminum was determined in the 0–15-, 15–23-, 23–30- and 30–45-cm depths of a Podzol limed to provide surface soil pH values ranging from 4.5 to 7.2. Both soluble and exchangeable Al decreased with increasing soil pH. Soluble Al ranged from 5.7 ppm at pH 4.4 with high fertilization to 0.3 ppm at pH 6.5 with similar fertilization. Increasing the rate of fertilization at pH 4.5 raised the soluble Al from 2.6 to 5.7 ppm. Fertilization still doubled the soluble Al in soil at pH 5.1 but had little effect as the pH was raised further to 5.8 and 6.5. Soluble Al in the subsoil samples was less than in surface soil samples at the same pH, while with exchangeable Al, the concentration was greater in the subsoil than in the surface soil samples.There was not a direct relationship between pH and soluble Al, although the highest soluble Al concentrations occurred at lowest soil pH levels. Analyses of 30 representative samples of surface soil taken from farmers' fields showed that the soluble Al concentration at pH 4.0 ranged from 3.5 to 4.8 ppm, while at a pH of 5.0 it ranged from 0.2 to 2.8 ppm. The concentrations of soluble Al in many of these soils exceeded the levels previously shown by nutrient solution experiments to severely restrict growth of legumes and some varieties of barley.

CONTRIBUTION OF EXCHANGEABLE ALUMINUM TO CATION EXCHANGE CAPACITY AT LOW pH

1987 ◽  
Vol 67 (1) ◽  
pp. 175-185 ◽  
Author(s):  
MARTIN DUQUETTE ◽  
WILLIAM H. HENDERSHOT
Keyword(s):  
Cation Exchange ◽  
Soil Ph ◽  
Cation Exchange Capacity ◽  
Exchange Capacity ◽  
Low Ph ◽  
Soil Samples ◽  
Maximum Amount ◽  
Exchangeable Al ◽  
Exchangeable Aluminum ◽  
Ph Dependent

The cation and anion exchange capacities (CEC and AEC) as functions of pH were measured for 12 soil samples from various parts of Quebec. In addition to the index cation Ca, Al was measured in the replacing solutions in order to evaluate the contribution of Al to pH-dependent CEC at low pH. Although all of the soils possessed some pH-dependent CEC, the soils with the steepest rise in CEC with pH were those with the largest accumulation of sesquioxides. The effective CEC, measured at the soil pH, ranged from 2.4 to 37.2 cmol(+) kg−1 while the CEC at pH 7 minus the CEC at pH3 varied from 4.4 to 39.9 cmol(+) kg−1. The maximum amount of exchangeable Al was found to correlate very highly with the amount of amorphous inorganic Al in the samples. The inclusion of exchangeable Al in the calculation did not significantly reduce the amount of pH-dependent CEC measured for the soils. Key words: Effective CEC, permanent charge, pH-dependent CEC

scholarly journals On the determination of soil pH

1965 ◽  
Vol 37 (1) ◽  
pp. 51-60
Author(s):  
Ritva Ryti
Keyword(s):  
Soil Ph ◽  
Salt Content ◽  
Soil Samples ◽  
Liquid Ratio ◽  
Ph Values ◽  
Water Suspensions ◽  
The Mean ◽  
The Difference ◽  
Soil Groups

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.

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