Factors affecting potassium release in calcareous soils of southern Iran

Experiments were conducted on 48 representative surface and subsurface soils collected from different climatic and physiographic conditions in southern Iran to assess factors affecting potassium (K) release and to find the best fitting models to describe the release kinetics of K to 0.01 m CaCl2. Mineralogical analysis showed that smectite, mica, chlorite, and palygorskite were the main clay minerals in the studied soils, whereas quartz, mica, and feldspars were abundant in the silt and sand fractions. Results indicated that cumulative K released ranged from 26.7 to 260 mg/kg (mean 176 mg/kg) for surface soils and from 37.9 to 198 mg/kg (mean 130 mg/kg) for subsurface soils. The predominant source of K in the soils appeared to be mica, because there was a significant relationship between cumulative K released and mica content. The percentage of non-exchangeable K release to CaCl2 during 1496 h was also correlated with the ratio of mica in the coarse fractions to total mica in the whole soil. Results showed that the Elovich equation adequately described the reaction rates of K release from surface and subsurface soils and suggested a heterogeneous diffusion process. We concluded that mica content and its particle size, soil depth, and some soil properties are the main factors controlling K release rate. On the other hand, we found no significant relationships between K release rate and climatic conditions, or physiographic positions.

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Kinetics of non-exchangeable potassium release in selected soil orders of southern Iran

Soil and Water Research ◽

10.17221/138/2017-swr ◽

2018 ◽

Vol 13 (No. 4) ◽

pp. 200-207

Author(s):

Zareian Gholamreza ◽

Farpoor Mohammad Hady ◽

Hejazi-Mehrizi Majid ◽

Jafari Azam

Keyword(s):

Oxalic Acid ◽

Soil Depth ◽

Clay Content ◽

Exchangeable K ◽

Southern Iran ◽

Successive Extraction ◽

Palygorskite Clay ◽

Kinetics Of ◽

K Release Rate ◽

K Release

Non-exchangeable K release can greatly influence soil K fertility. This study was carried out to study the release of non-exchangeable K from 22 surface and subsurface soils of southern Iran using successive extraction with 10 mmol/l of CaCl2 and oxalic acid in a period of 2−1368 h at 25 ± 1°C. Alfisols, Aridisols, Entisols, Inceptisols, Mollisols, and Histosols were among the studied soil orders. Illite, smectite, chlorite, vermiculite, kaolinite and palygorskite clay minerals were identified. The amount of non-exchangeable K varied from 95 to 506 mg/kg. Results showed that CaCl2 and oxalic acid released 60 and 55% of non-exchangeable K from soils, respectively. The discontinuity in slope was found when the cumulative amount of released K was plotted versus time, supporting the multi-reactive nature of K exchange sites. The cumulative K release in soils ranged from 87 to 300 mg/kg for CaCl2 and 78 to 300 mg/kg for oxalic acid which was well described by simplified Elovich and power function equations. The b constant of simplified Elovich as an index of non-exchangeable K release rate was in the range of 10 to 36 mg/kg for CaCl2 and 11 to 36 mg/kg for oxalic acid. The highest b constant was measured in Inceptisols and Alfisols, while the lowest values were found in Entisols and Histosols. In conclusion, the K release pattern was similar for both extractants and affected by clay content and type, and soil depth.

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Factors Affecting Potassium Pools Distribution in Calcareous Soils of Southern Iran

Arid Land Research and Management ◽

10.1080/15324982.2011.602177 ◽

2011 ◽

Vol 25 (4) ◽

pp. 313-327 ◽

Cited By ~ 12

Author(s):

Mahdi Najafi Ghiri ◽

Ali Abtahi ◽

Hamidreza Owliaie ◽

Soheila Sadat Hashemi ◽

Hadi Koohkan

Keyword(s):

Calcareous Soils ◽

Factors Affecting ◽

Southern Iran

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Potassium release kinetics and its correlation with pinto bean (Phaseolus vulgaris) plant indices

Plant Soil and Environment ◽

10.17221/70/2012-pse ◽

2012 ◽

Vol 58 (No. 7) ◽

pp. 328-333 ◽

Cited By ~ 16

Author(s):

A.R. Hosseinpur ◽

H.R. Motaghian ◽

M.H. Salehi

Keyword(s):

Release Kinetics ◽

Calcareous Soils ◽

Bean Plant ◽

Pinto Bean ◽

Successive Extraction ◽

Release Studies ◽

Function Models ◽

Kinetics Of ◽

Total Reaction Time ◽

K Release

The rate of potassium (K) release from soils is a dynamic process, and it is important to the evaluation of soil K availability to plant. The objectives of this study were to determine K release characteristics and the correlation of these parameters with bean plant indices in surface soils of 15 calcareous soils. The kinetics of K release was determined by successive extraction with 0.01 mol/L CaCl2 in a period of 2–2017 h at 25 ± 1°C. The results showed that the cumulative K&rlm; release ranged from 111 to 411 mg/kg. A plot of cumulative amount of K released showed a discontinuity in slope at 168 h. Thus, two equations were applied to segments of the total reaction time (2 to 168 and 168 to 2017 h). The amounts of K released during 2–168 and 168–2017 h ranged from 55 to 299 and 44 to 119 mg/kg, respectively. Release kinetics of K conformed fairly well to parabolic diffusion, simplified Elovich and power function models in two segments. Potassium released after 2–168 and 168–2017 h and K release rate constants were significantly correlated (P < 0.05) with bean plant indices, while correlation between K extracted by using 1 mol/L NH4OAc (ammonium acetate) and plant indices was not significant. The results of this research showed that information obtained from K release studies in laboratory and kinetics equation parameters can help to estimate the K supplying power of soils.

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Potassium Pools Distribution in Some Calcareous Soils as Affected by Climatic Conditions, Physiographic Units, and Some Physicochemical Properties in Fars Province, Southern Iran

Eurasian Soil Science ◽

10.1134/s1064229321050021 ◽

2021 ◽

Vol 54 (5) ◽

pp. 702-715

Author(s):

Abolfazl Azadia ◽

Sirous Shakeri

Keyword(s):

Physicochemical Properties ◽

Calcareous Soils ◽

Climatic Conditions ◽

Fars Province ◽

Southern Iran

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Factors affecting potassium fixation in calcareous soils of southern Iran

Archives of Agronomy and Soil Science ◽

10.1080/03650340.2010.507194 ◽

2012 ◽

Vol 58 (3) ◽

pp. 335-352 ◽

Cited By ~ 16

Author(s):

M. Najafi Ghiri ◽

Ali Abtahi

Keyword(s):

Calcareous Soils ◽

Factors Affecting ◽

Potassium Fixation ◽

Southern Iran

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Factors Affecting Micronutrient Availability in Calcareous Soils of Southern Iran

Arid Land Research and Management ◽

10.1080/15324982.2012.719570 ◽

2013 ◽

Vol 27 (3) ◽

pp. 203-215 ◽

Cited By ~ 14

Author(s):

M. Najafi-Ghiri ◽

R. Ghasemi-Fasaei ◽

E. Farrokhnejad

Keyword(s):

Calcareous Soils ◽

Factors Affecting ◽

Southern Iran ◽

Micronutrient Availability

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Effects of zeolite and vermicompost applications on potassium release from calcareous soils

Soil and Water Research ◽

10.17221/72/2012-swr ◽

2014 ◽

Vol 9 (No. 1) ◽

pp. 31-37 ◽

Cited By ~ 10

Author(s):

M. Najafi-Ghiri

Keyword(s):

Calcareous Soils ◽

Soil Samples ◽

Exchangeable K ◽

Fertility Management ◽

Significant Relationships ◽

Elovich Equation ◽

Kinetics Of ◽

Positive Effect ◽

K Release Rate ◽

K Release

Zeolite and vermicompost applications to soil may improve K fertility of soils. For this purpose, these materials were added to five representative calcareous soils collected from southern Iran. The treatments included (1) control, (2) 20 g/kg zeolite, (3) 20 g/kg vermicompost, and (4) 20 g/kg vermicompost + zeolite (1:1). The samples were incubated for 90 days, and the concentrations of soluble, exchangeable, and non-exchangeable K and K release rate to 0.01M CaCl2 during 240 min (16 successive 15 min extractions of soil samples with CaCl2 solution) were determined. Results indicated that zeolite application increased significantly the concentration of soluble and exchangeable K. Vermicompost application had a positive effect on all forms of K. Cumulative K release was also affected by vermicompost application. Comparison of experimental data to different kinetic models indicated that Elovich, power function, and parabolic diffusion models described well kinetics of K release from all soil samples to 0.01M CaCl2. The b values of Elovich equation had significant relationships with NH4OAc- and HNO3-extractable K. It is recommended that for K fertility management of calcareous soils, organic and inorganic amendments application to soils should be taken into consideration.

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113 ESTIMATING SOIL. POTASSIUM SUPPLY TO MEET PROCESSING TOMATO REQUIREMENTS

HortScience ◽

10.21273/hortsci.29.5.444d ◽

1994 ◽

Vol 29 (5) ◽

pp. 444d-444

Author(s):

T. K. Hartz

Keyword(s):

Release Rate ◽

Application Timing ◽

Exchangeable K ◽

Processing Tomato ◽

K Deficiency ◽

Potassium Supply ◽

Fixation Capacity ◽

Highly Correlated ◽

K Release Rate ◽

K Release

A 1993 survey of 50 commercial processing tomato fields in California revealed widespread potassium deficiency, as determined by tissue K levels below existing sufficiency standards and the occurrence of vine necrosis consistent with K deficiency. Soils from these fields were analyzed for exchangeable K by ammonium acetate extraction, and for K release rate by a 7 day incubation procedure (1:10 soil:. 01 M CaCl2 at 25°). Soil K release rate was more highly correlated with tissue K at midseason than was exchangeable K. These soils were further examined for K fixation capacity. Three g soil was blended with 3 ml 10 meq K as KNO3, allowed to dry, incubated for 7 days in a 1:10 soil: H2O solution, then extracted in 1 N NH4Cl; added K not recovered was considered fixed. Percent K fixation ranged from 0 to 82%. These data suggest that the inconsistent response of processing tomato to K application in numerous California trials may be related to a) the reliance on extractable K analysis to characterize soil K supply and b) no consideration of soil K fixation capacity in determining K application timing and method.

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ROLE OF ADDED PHOSPHOGYPSUM AND HUMIC ACIDS IN THE KINETIC RELEASE OF SALT FROM SALT AFFECTED SOIL (SALINE – SODIC)

Anbar Journal of Agricultural Sciences ◽

10.32649/ajas/2020/2 ◽

2020 ◽

pp. 15-27

Keyword(s):

Electrical Conductivity ◽

Humic Acids ◽

Release Rate ◽

Release Kinetics ◽

Sodium Adsorption Ratio ◽

Salt Affected Soil ◽

Two Factors ◽

Dissolved Ions ◽

Kinetic Release

In order to study the effect of phosphogypsum and humic acids in the kinetic release of salt from salt-affected soil, a laboratory experiment was conducted in which columns made from solid polyethylene were 60.0 cm high and 7.1 cm in diameter. The columns were filled with soil so that the depth of the soil was 30 cm inside the column, the experiment included two factors, the first factor was phosphogypsum and was added at levels 0, 5, 10 and 15 tons ha-1 and the second-factor humic acids were added at levels 0, 50, 100 and 150 kg ha-1 by mixing them with the first 5 cm of column soil and one repeater per treatment. The continuous leaching method was used by using an electrolytic well water 2.72 dS m-1. Collect the leachate daily and continue the leaching process until the arrival of the electrical conductivity of the filtration of leaching up to 3-5 dS m-1. The electrical conductivity and the concentration of positive dissolved ions (Ca, Mg, Na) were estimated in leachate and the sodium adsorption ratio (SAR) was calculated. The results showed that the best equation for describing release kinetics of the salts and sodium adsorption ratio in soil over time is the diffusion equation. Increasing the level of addition of phosphogypsum and humic acids increased the constant release velocity (K) of salts and the sodium adsorption ratio. The interaction between phosphogypsum and humic acids was also affected by the constant release velocity of salts and the sodium adsorption ratio. The constant release velocity (K) of the salts and the sodium adsorption ratio at any level of addition of phosphogypsum increased with the addition of humic acids. The highest salts release rate was 216.57 in PG3HA3, while the lowest rate was 149.48 in PG0HA0. The highest release rate of sodium adsorption ratio was 206.09 in PG3HA3, while the lowest rate was 117.23 in PG0HA0.

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