scholarly journals PERFORMANCE OF LINEAR MODELS IN PREDICTING CATION EXCHANGE CAPACITY OF CALCAREOUS SOILS

2021 ◽  
Vol 52 (6) ◽  
pp. 1489-1497
Author(s):  
M. A. Fattah ◽  
K. H. Karim

Determination of soil cation exchange capacity (CEC) in lab is cumbersome, time consuming, and costly. Accordingly, this article attempted to formulate pedotransfer functions for predicting it using some soil physical and chemical properties e.g., sand (SA), silt (SI), clay (CL), organic matter (OM) and calcium carbonate (CC). This research included four steps: preparing soil database; selecting independent variables which are related to CEC value; formulating models using NCSS 12.0.2 software, and the last step is to achieve specific objective of the research which is the comparsion among models by a series of efficiency criteria: root mean square error (RMSE), Nash-Sutcliffe model efficiency coefficient (EF), average absolute percent error (AAPE), and percentage of improving model efficiency (PIME). The statistical results of the research indicated that CEC of calcareous soils could be predicted from models that have one variable (CL), two variables (CL and OM), and three variables (CL, OM, and CC) with slight decrease in the RMSE (2.95402, 2.81180, and 2.79268) respectively, and slight increase in the EF (0.887360, 0.898448, and 0.90023) respectively. While the reliable models to predict soil CEC are formulated from the fewer number of independent variables with having the lowest points of the standardized residual of CEC that greater than +2 cmolc kg-1).

Molecules ◽  
2019 ◽  
Vol 24 (16) ◽  
pp. 3015
Author(s):  
Fethi Kooli ◽  
Souad Rakass ◽  
Yan Liu ◽  
Mostafa Abboudi ◽  
Hicham Oudghiri Hassani ◽  
...  

The effect of the counteranion of hexadecyltrimethylammonium salts on the physico-chemical properties of organoclays was investigated, using a selected natural clay mineral with a cation exchange capacity of 95 meq/100 g. The uptake amount of C16 cations was dependent on the hexadecyltrimethylammonium (C16) salt solution used, the organoclay prepared from C16Br salt solution exhibited a value of 1. 05 mmole/g higher than those prepared from C16Cl and C16OH salt solutions. The basal spacing of these organoclays was in the range of 1.81 nm to 2.10 nm, indicating a similar orientation of the intercalated surfactants, and could indicated that the excess amount of surfactants, above the cation exchange capacity of 0.95 meq/g could be adsorbed on the external surface of the clay mineral sheets. These organoclays were found to be stable in neutral, acidic, and basic media. The thermal stability of these organoclays was carried out using thermogravimetric analysis and in-situ X-ray diffraction (XRD) techniques. The decomposition of the surfactant occurred at a maximum temperature of 240 °C, accompanied with a decrease of the basal spacing value close to 1.42 nm. The application of these organoclays was investigated to remove an acidic dye, eosin. The removal amount was related to the initial used concentrations, the amount of the surfactants contents, and to the preheated temperatures of the organoclays. The removal was found to be endothermic process with a maximum amount of 55 mg of eosin/g of organoclay. The value decreased to 25 mg/g, when the intercalated surfactants were decomposed. The reuse of these organoclays was limited to four regeneration recycles with a reduction of 20 to 30%. However, noticeable reduction between 35% to 50% of the initial efficiency, was achieved after the fifth cycle, depending of the used organoclays.


Author(s):  
Resman ◽  
Sahta Ginting ◽  
Muhammad Tufaila ◽  
Fransiscus Suramas Rembon ◽  
Halim

The research aimed to determine the effectiveness of compost containing humic and fulvic acids, and pure humic and fulvic acids in increasing of Ultisol soil chemical properties. The research design used a randomized block design (RBD), consisting of 10 treatments, namely K0: 0 g polybag-1, KO1: 500 g polybag-1, KO2: 500 g polybag-1, KO3: 500 g polybag-1, KO4: 500 g polybag-1, KO5: 500 g polybag-1, KO6: 500 g polybag-1, KO7: 500 g of polybags-1, H: 50 g of polybag-1, A: 500 g polybag-1. Each treatment was repeated three times and obtained 30 treatment units. The results showed that pH H2O (K0: 4.49, KO1: 5.64, KO2: 5.47, KO3: 5.43, KO4: 5.51, KO5: 5.39, KO6: 5.48, KO7: 6.17, H: 5.06, F: 5.15), total-N (%) (K0: 0.13, KO1: 0.17, KO2: 0.18, KO3: 0.30, KO4: 0.25, KO5: 0.24, KO6: 0.29, KO7: 0.36, H: 0.16, F: 0.14), organic-C (%) (K0: 1.85, KO1; 2.30, KO2: 2.24, KO3: 2.33, KO4: 2.62, KO5: 2.25, KO6: 2.27, KO7: 2.95, H: 2.32, F: 2.26) , available-P (%) (K0: 2.75, KO1: 3.24, KO2: 3.16, KO3: 3.27, KO4: 3.57, KO5: 3.31, KO6: 3.37, KO7: 3.89, H: 3.10, F: 3.12), exchangeable-Al (me100g-1) (K0: 2.51, KO1: 2.11, KO2: 2.13, KO3: 2.15, KO4: 1.88, KO5: 2.14, KO6: 2.12, KO7: 1.75, H: 2.16, F: 2.17), base saturation (%) (K0: 30.91, KO1: 63.48, KO2: 52.63, KO3: 53.76, KO4: 56.13, KO5: 54.96, KO6: 56.71, KO7: 65.53, H: 39.11, F: 42.76), cation exchange capacity (me100g-1) (K0: 12.76, KO1: 15.64, KO2: 14.86, KO3: 14.35, KO4: 14.13, KO5: 15.01, KO6: 15.50, KO7: 17.94, H: 14.19, F: 13.73). The combined compost treatment of three types of organic matter (Imperata cylindrica + Rice straw + Glincidia sepium) is more effective in increasing the pH, H2O as 37.42%, total-N as 176.92%, Organic-C as 59.46%, available-P as 41.45%, base saturation as 65.53%, cation exchange capacity as 17.94% and exchangeable -Al, Alreduction as 30.28% of ultisol soil. KEY WORDS: compost, humic acid, fulvate, soil chemical, ultisol


2021 ◽  
Vol 70 (1) ◽  
pp. 13-26
Author(s):  
Miodrag Tolimir ◽  
Branka Kresović ◽  
Borivoj Pejić ◽  
Katarina Gajić ◽  
Angelina Tapanarova ◽  
...  

The impact of long-term (> 100 yr) irrigation on soil chemical properties was studied on eight plots in the Beli Drim river valley in Kosovo and Metohija near Klina, Serbia. For these studies, soil samples from shallow profiles were collected from only one or two depth zones of the Ah horizon; and from moderately deep and deep profiles, from two to three depth zones for the purpose of comparing irrigated field and non-irrigated meadow lands. Water from the Beli Drim River and surface gravity systems (irrigation furrows or border strip irrigation) were used for irrigation. Chemical variables included determination of pH-H2O, content of CaCO3, content of humus, hydrolytic acidity, sum of basic cations, cation exchange capacity, and base saturation. On irrigated soils, the results of chemical analysis showed on average a small increase in pH-H2O (0.07 pH units), as well as a significant decrease in humus content (2.00-4.75%), sum of basic cations (4.98-12.98%) and cation exchange capacity (12.8%) compared to the non-irrigated land of the study area. Long-term irrigation had no effect on hydrolytic acidity and base saturation in the Ah horizon of the investigated lands. Namely, the mentioned variations in the chemical properties of the investigated soils show that slight processes of reduction in the humus content and reduction of the content of base cations occured. Data on the chemical properties of the investigated soils indicate that the destructive processes of reduction in the humus content and leaching of base cations must be controlled in order to achieve a stable sustainable system of high productivity and prevent their further deterioration.


2014 ◽  
Vol 21 (3) ◽  
pp. 487-498 ◽  
Author(s):  
Dawid Jaremko ◽  
Dorota Kalembasa

Abstract The object of this study was to compare the results obtained with four methods of determination of cation exchange capacity (CEC) and sum of exchangeable cations (Ca, Mg, K) in soils. One of these methods is Kappen’s method and the others methods are based on different extracting reagents: sodium acetate (pH = 8.2), barium chloride and hexaamminecobalt(III) chloride. Values measured with barium ions and hexaamminecobalt(III) ions as index cations are very comparable and these two methods can be considered as equivalent. Kappen’s method gives overestimated results, especially for acid soils reach in organic matter and very calcareous soils. Sodium acetate, buffering the pH of the extracting solution, causes increase of numbers of negatively charged sites and particularly those bonded to organic matter and for this reason values obtained with this method are overestimated. Nevertheless, it is possible to correct this error for a given soil sample by regression equation considering pH of soil, clay and organic carbon content.


2019 ◽  
Vol 4 (3) ◽  
pp. 131
Author(s):  
Ratna Taher ◽  
Makruf Nurudin ◽  
Eko Hanudin

Understanding the nature of the soil is very important to know the potential and the proper management of the soil. This study aimed to determine the differences in morphological, physical, and chemical properties of the soils developing from gabbro, phylitte and chert parent materials. The soil profile was made to represent each parent rock of gabbro, phyllite and chert located on the upper and middle slopes with pine-dominated vegetation and mixed gardens. Observation in the field is a professional description to observe soil morphology. Soil samples were taken at each horizon to analyze soil physical properties (bulk density, particle density, and texture), soil chemical properties (pH, exchanged cations, cation exchange capacity, available P, organic C, and total N). Texture analysis results showed that clay content of the soil developing from parent rock of Gabro 1 is the highest, followed by the soil clay content from  Chert 1, Phyllite 1, Chert 2, Phyllite 2, and Gabbro 2, respectively. The order of soil acidity level (pH) is Gabbro 2 > Gabbro 1> Chert 1 ~ Chert 2 > Phyllite 1 ~ Phyllite 2. Meanwhile, the order of the cation exchange capacity is Gabbro 1> Gabbro 2> Phyllite 1> Chert 1> Phyllite 2> Chert 2, and the order of the base saturation is Chert 2> Gabbro 2> Chert 1> Phyllite 2 > Phyllite1> Gabbro 1.


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