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D. K. Pal - One of the best experts on this subject based on the ideXlab platform.
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Role of Calcium Carbonate and Palygorskite in Enriching Exchangeable Magnesium to Impair Drainage of Vertisols of Semi-Arid Western India
Clay Research, 2017Co-Authors: Swati P. Zade, P. Chandran, D. K. PalAbstract:Shrink-swell soils (Vertisols and their intergrades) as one of the major soils support high crop production in Maharashtra, Madhya Pradesh, Andhra Pradesh and northern Karnataka. Vertisols occur extensively in the states of Maharashtra, occupying 36% of the total area. Under rain-fed conditions, the yield of deep-rooted crops on Vertisols depends primarily on the amount of rainwater stored at depth in the soil profile and the extent to which this soil water is released during crop growth. Both the retention and release of soil water are governed by the nature and content of clay minerals, and also by the nature of the Exchangeable cations such as sodium and Magnesium. The hydraulic conductivity and clay dispersion of swell shrink soils as a function of Exchangeable sodium and Magnesium are two important soil properties that need to be understood in view of their concurrent pedogenic processes like clay illuviation, calcium carbonate formation and enrichment of Exchangeable sodium and Magnesium in the subsoils. Therefore, the present study was undertaken with thirteenVertisols of semi-arid tropical (SAT) western Maharashtra. Results of this study indicate the formation of pedogenic calcium carbonate (PC) triggers the chemical reaction for the concomitant enrichment of Exchangeable sodium(ESP) and Exchangeable Magnesium percentage (EMP) in the subsoils and development of Sodic Haplusterts (ESP > 5) witha low value of sHC (
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role of calcium carbonate and palygorskite in enriching Exchangeable Magnesium to impair drainage of vertisols of semi arid western india
Clay Research, 2017Co-Authors: Swati P. Zade, P. Chandran, D. K. PalAbstract:Shrink-swell soils (Vertisols and their intergrades) as one of the major soils support high crop production in Maharashtra, Madhya Pradesh, Andhra Pradesh and northern Karnataka. Vertisols occur extensively in the states of Maharashtra, occupying 36% of the total area. Under rain-fed conditions, the yield of deep-rooted crops on Vertisols depends primarily on the amount of rainwater stored at depth in the soil profile and the extent to which this soil water is released during crop growth. Both the retention and release of soil water are governed by the nature and content of clay minerals, and also by the nature of the Exchangeable cations such as sodium and Magnesium. The hydraulic conductivity and clay dispersion of swell shrink soils as a function of Exchangeable sodium and Magnesium are two important soil properties that need to be understood in view of their concurrent pedogenic processes like clay illuviation, calcium carbonate formation and enrichment of Exchangeable sodium and Magnesium in the subsoils. Therefore, the present study was undertaken with thirteenVertisols of semi-arid tropical (SAT) western Maharashtra. Results of this study indicate the formation of pedogenic calcium carbonate (PC) triggers the chemical reaction for the concomitant enrichment of Exchangeable sodium(ESP) and Exchangeable Magnesium percentage (EMP) in the subsoils and development of Sodic Haplusterts (ESP > 5) witha low value of sHC (<10 mmhr1). It was interesting to note similar low values of sHC in Typic Haplusterts endowed with palygorskite mineral. Results indicate that when the impairment of sHC in Sodic Haplusterts is primarily due to increase in ESP and EMP, the enrichment of EMP caused by the presence of palygorskite in Typic Haplusterts is equally capable of impairing the drainage (in terms of hydraulic properties) of Vertisols. This is the opposite effect from that of saturation with Ca2+ ions, which leads to blocking of small pores in the soil. This suggests that Mg2+ ions are less efficient than Ca2+ ions in flocculating soil colloids and also in creating strong plasma separation although the United States Salinity Research Laboratory grouped Ca2+ and Mg2+ together as both the ions improve soil structure. This fact assumes a great importance in the use and management of palygorskite endowed Vertisols especially when they are still classed as Typic Haplusterts, suggesting no sign of natural soil degradation in them.
Long Zhiqi - One of the best experts on this subject based on the ideXlab platform.
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Recovery of rare earth from the ion-adsorption type rare earths ore: II. Compound leaching
Hydrometallurgy, 2016Co-Authors: Xiao Yanfei, Feng Zongyu, Huang Xiaowei, Chen Yingying, Liu Xiangsheng, Wang Liangshi, Long ZhiqiAbstract:Abstract In order to coordinate the content and ratio of ion-Exchangeable calcium and ion-Exchangeable Magnesium in the soil and reduce ammonia nitrogen pollution, recovery of rare earth from the ion-adsorption type rare earths ore with Magnesium–ammonium, Magnesium–calcium and Magnesium–ammonium–calcium compound leaching agent was studied in this paper. Results showed that the leaching ability was in the order of (NH 4 ) 2 SO 4 > NH 4 Cl > MgSO 4 > MgCl 2 ≈ CaCl 2 under the same total cationic charge. The content of ion-Exchangeable Magnesium and ion-Exchangeable calcium in water washing tailings could be adjusted to be suitable for the plant growth by changing the composition of leaching agent. In the Magnesium–ammonium–calcium compound leaching system, when the mole ratio of Magnesium–ammonium–calcium was 15:25:60, 628.57 mg·kg − 1 ion-Exchangeable Magnesium and 77.77 mg·kg − 1 ion-Exchangeable calcium in water washing tailings were achieved, while the ratio of ion-Exchangeable calcium and Magnesium was 8.08. Moreover, the aluminum leaching efficiency was only 49.2% and the rare earth leaching efficiency could be above 94%. Furthermore, the soybeans could grow normally with water washing tailings in Magnesium–ammonium–calcium compound leaching system with an average plant height of 25.5 cm. The application of Magnesium–ammonium–calcium compound leaching agent could significantly reduce the ammonia nitrogen pollution, maintain the soil nutrient so as to reduce the dosage of calcium–Magnesium fertilizer, and may realize the ecological friendly leaching of the ion-adsorption type rare earths ore.
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recovery of rare earths from weathered crust elution deposited rare earth ore without ammonia nitrogen pollution i leaching with Magnesium sulfate
Hydrometallurgy, 2015Co-Authors: Xiao Yanfei, Feng Zongyu, Huang Xiaowei, Chen Yingying, Wang Liangshi, Huang Li, Long ZhiqiAbstract:Abstract The practice of in-situ leaching of weathered crust elution-deposited rare earth ore using (NH 4 ) 2 SO 4 solution has revealed serious environmental problems such as ammonia-nitrogen pollution in water body and plant growth difficulties. The present study investigated the use of Magnesium sulfate instead of (NH 4 ) 2 SO 4 as the leaching agent in the recovery of rare earth elements to solve the problem of ammonia-nitrogen pollution. It was determined that the optimum leaching condition in 298 K, a flow rate of 0.60 mL·min − 1 , and 0.20 mol·L − 1 Magnesium sulfate solution, lead to 93% of total rare earth leaching efficiency and around 50% aluminum leaching efficiency. The results suggested that the Magnesium sulfate was capable of producing identical recovery efficiency as (NH 4 ) 2 SO 4 and reducing aluminum leaching efficiency at the same time. In addition, the leaching mechanism was analyzed with different kinetic models, it was determined that the leaching kinetics of the weathered crust elution-deposited rare earth ore could be appropriately described by Pseudo-first-order model, which indicated that the film diffusion was rate-limiting for the leaching process. The apparent activation energy was calculated to be 8.90 kJ·mol − 1 . However, the content of ion-Exchangeable Magnesium in rare earth washing tailings was 560 mg per kilogram soil. This would lead to an imbalance of ion-Exchangeable calcium and ion-Exchangeable Magnesium, which would have a bad effect on the plant growth. Based on these findings, the synergic leaching with Magnesium salt and calcium salt was identified as an excellent alternative leaching agent for further studies.
Swati P. Zade - One of the best experts on this subject based on the ideXlab platform.
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Role of Calcium Carbonate and Palygorskite in Enriching Exchangeable Magnesium to Impair Drainage of Vertisols of Semi-Arid Western India
Clay Research, 2017Co-Authors: Swati P. Zade, P. Chandran, D. K. PalAbstract:Shrink-swell soils (Vertisols and their intergrades) as one of the major soils support high crop production in Maharashtra, Madhya Pradesh, Andhra Pradesh and northern Karnataka. Vertisols occur extensively in the states of Maharashtra, occupying 36% of the total area. Under rain-fed conditions, the yield of deep-rooted crops on Vertisols depends primarily on the amount of rainwater stored at depth in the soil profile and the extent to which this soil water is released during crop growth. Both the retention and release of soil water are governed by the nature and content of clay minerals, and also by the nature of the Exchangeable cations such as sodium and Magnesium. The hydraulic conductivity and clay dispersion of swell shrink soils as a function of Exchangeable sodium and Magnesium are two important soil properties that need to be understood in view of their concurrent pedogenic processes like clay illuviation, calcium carbonate formation and enrichment of Exchangeable sodium and Magnesium in the subsoils. Therefore, the present study was undertaken with thirteenVertisols of semi-arid tropical (SAT) western Maharashtra. Results of this study indicate the formation of pedogenic calcium carbonate (PC) triggers the chemical reaction for the concomitant enrichment of Exchangeable sodium(ESP) and Exchangeable Magnesium percentage (EMP) in the subsoils and development of Sodic Haplusterts (ESP > 5) witha low value of sHC (
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role of calcium carbonate and palygorskite in enriching Exchangeable Magnesium to impair drainage of vertisols of semi arid western india
Clay Research, 2017Co-Authors: Swati P. Zade, P. Chandran, D. K. PalAbstract:Shrink-swell soils (Vertisols and their intergrades) as one of the major soils support high crop production in Maharashtra, Madhya Pradesh, Andhra Pradesh and northern Karnataka. Vertisols occur extensively in the states of Maharashtra, occupying 36% of the total area. Under rain-fed conditions, the yield of deep-rooted crops on Vertisols depends primarily on the amount of rainwater stored at depth in the soil profile and the extent to which this soil water is released during crop growth. Both the retention and release of soil water are governed by the nature and content of clay minerals, and also by the nature of the Exchangeable cations such as sodium and Magnesium. The hydraulic conductivity and clay dispersion of swell shrink soils as a function of Exchangeable sodium and Magnesium are two important soil properties that need to be understood in view of their concurrent pedogenic processes like clay illuviation, calcium carbonate formation and enrichment of Exchangeable sodium and Magnesium in the subsoils. Therefore, the present study was undertaken with thirteenVertisols of semi-arid tropical (SAT) western Maharashtra. Results of this study indicate the formation of pedogenic calcium carbonate (PC) triggers the chemical reaction for the concomitant enrichment of Exchangeable sodium(ESP) and Exchangeable Magnesium percentage (EMP) in the subsoils and development of Sodic Haplusterts (ESP > 5) witha low value of sHC (<10 mmhr1). It was interesting to note similar low values of sHC in Typic Haplusterts endowed with palygorskite mineral. Results indicate that when the impairment of sHC in Sodic Haplusterts is primarily due to increase in ESP and EMP, the enrichment of EMP caused by the presence of palygorskite in Typic Haplusterts is equally capable of impairing the drainage (in terms of hydraulic properties) of Vertisols. This is the opposite effect from that of saturation with Ca2+ ions, which leads to blocking of small pores in the soil. This suggests that Mg2+ ions are less efficient than Ca2+ ions in flocculating soil colloids and also in creating strong plasma separation although the United States Salinity Research Laboratory grouped Ca2+ and Mg2+ together as both the ions improve soil structure. This fact assumes a great importance in the use and management of palygorskite endowed Vertisols especially when they are still classed as Typic Haplusterts, suggesting no sign of natural soil degradation in them.
A.j. Maclean - One of the best experts on this subject based on the ideXlab platform.
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Influence of Additions of Lime to Soils on the Availability of Potassium and Other Cations for Alfalfa1
Canadian Journal of Agricultural Science, 2016Co-Authors: A.j. MacleanAbstract:In a greenhouse experiment comprising six soils, varying in reaction from about pH 5 5 to 6 0, addition of calcium hydroxide had no appreciable effect on Exchangeable potassium but resulted in a slight reduction in water-soluble potassium in some of the soils. With successive increases in the pH of the soils and associated increases in Exchangeable and water-soluble calcium, there was an appreciable reduction in Exchangeable Magnesium. The potassium and Magnesium contents of alfalfa grown on the soils tended to decrease with liming, whereas the calcium content increased Increase in yield resulting from addition of potassium fertilizer was usually accompanied by a decrease in the sum of cations in the plants Cropping resulted in a marked reduction in the Exchangeable potassium The decline in Exchangeable potassium in the clay soils accounted for a smaller proportion of the potassium removed by the crop than did the decline in the sandy soils.
Yves Rayssiguier - One of the best experts on this subject based on the ideXlab platform.
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Exchangeable Magnesium pool masses in spontaneously hypertensive rats.
Metabolism: clinical and experimental, 2003Co-Authors: Christine Feillet-coudray, Yves Rayssiguier, Elyett Gueux, Claudine Lab, Charles CoudrayAbstract:We explored Magnesium (Mg) metabolism by determination of Exchangeable Mg pool masses and Mg kinetic parameters using stable Mg isotopes in spontaneously hypertensive rats (SHRs). Classical intracellular and extracellular Mg status biomarkers were also measured. Male SHRs and their male Wistar Kyoto (WKY) controls were fed a semipurified diet containing Mg 550 mg /kg for 2 weeks. Each rat received then an intravenous injection of 1.37 mg (25)Mg. The plasma (25)Mg disappearance curve over the next 7 days was used to measure the mass and fractional transport rate of 3 rapidly exchanging Mg metabolic pools, M1, M2, and M3. In the SHRs, plasma and erythrocyte Mg levels and urinary Mg excretion were not modified compared with their control WKYs, but tibia Mg level was significantly lower in the SHRs. Pool M3, the deep tissue pool, was significantly lower in SHRs compared with WKYs, but pools M1 and M2, the extracellular Mg pools, were statistically similar. The fractional transport rate of Mg from M1 to M2 and from M2 to M1 in the SHRs was higher than in the controls. The half-life of M1 was significantly decreased in SHRs compared with WKYs. In conclusion, this work demonstrates a decrease in intracellular Mg stores in SHRs compared with WKYs and disturbance of Mg exchanges in extracellular Mg, confirming a Mg metabolism disturbance in spontaneously hypertensive rats. Further work is now needed to elucidate the origin of the Mg depletion in SHRs and to explore Mg pools in hypertensive patients.
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Exchangeable Magnesium pool masses in healthy women: effects of Magnesium supplementation
The American journal of clinical nutrition, 2002Co-Authors: Christine Feillet-coudray, Charles Coudray, Jean Claude Tressol, Denise Pépin, Andrzej Mazur, Steven A. Abrams, Yves RayssiguierAbstract:BACKGROUND Studying Magnesium pools in the body with use of stable isotopes may be helpful for evaluating Magnesium status. Data on the evaluation of Magnesium pools in humans are scarce. OBJECTIVE We undertook this study to evaluate the effects of a Magnesium supplementation program on the size of the Exchangeable body pools of Magnesium and on classic indexes of Magnesium status in healthy women with normal Magnesium status. DESIGN Ten healthy women participated in a kinetic study with Magnesium stable isotopes before and after 8 wk of Magnesium supplementation. Each woman received 3 supplements containing 5.08 mmol (122 mg) elemental Mg/d (366 mg/d). Before and at the end of the supplementation period, each woman received an intravenous injection of 1.67 mmol (40 mg) (25)Mg, and the plasma Magnesium disappearance curve was followed for the next 7 d. Two methods were used to analyze the Exchangeable pools of Magnesium: 1) formal multicompartmental modeling and 2) a simplified estimation of the total mass of the rapidly Exchangeable Magnesium pool (EMgP). RESULTS In these healthy women, Exchangeable Magnesium pools represented 11-12% of total body Magnesium on the basis of multicompartmental analysis. The simplified estimation of EMgP overestimated the size of the Exchangeable Magnesium pools by approximately 45-50%. Eight weeks of Magnesium supplementation did not significantly modify the size of the Exchangeable Magnesium pools, whereas urinary Magnesium excretion was significantly higher after 8 wk of supplementation. CONCLUSION Women with no clinical evidence of Magnesium deficiency may not respond to short-term supplementation with increases in the mass of the Exchangeable Magnesium body pool or in Magnesium turnover rates.
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Exchangeable Magnesium Pool Masses Reflect the Magnesium Status of Rats
The Journal of nutrition, 2000Co-Authors: Christine Feillet-coudray, Charles Coudray, Andrzej Mazur, Steven A. Abrams, Elyett Gueux, Fabienne Brûlé, Yves RayssiguierAbstract:A sensitive and valid marker to assess Magnesium (Mg) status in humans is not available. The kinetically determined Exchangeable pool masses have been used for other minerals, such as zinc and selenium, as markers of whole-body mineral status. To evaluate the validity of this relationship for Mg, we measured the Exchangeable pools of Mg in rats over a range of Magnesium dietary intakes. Rats weighing ∼170 g were fed a control diet (500 mg Mg/kg), a marginally Mg-deficient diet (200 mg/kg) or a severely Mg-deficient diet (60 mg Mg/kg) for 2 wk. Subsequently, rats were administered an intravenous injection of 25 Mg, and the plasma 25 Mg disappearance curve was followed for the next 7 d. The following two methods were employed to analyze the Exchangeable pools of Mg: 1) formal compartmental modeling and 2) a simplified determination of the total mass of the rapidly Exchangeable Mg pool (EMgP). The mass of the three Exchangeable pools (two extracellular pools and one intracellular pool) determined by compartmental analysis decreased in proportion to dietary Mg intake. EMgP, the combined pools of Mg that exchange with the plasma Mg within 48 h, decreased significantly as dietary Mg was lowered. It was positively correlated with conventional markers of Mg status (total Mg in plasma, erythrocyte and tibia Mg levels). Compartmental analysis assesses Mg Exchangeable pools more accurately, but determination of EMgP is simpler and faster. Our findings demonstrate that the Exchangeable pools of Mg constitute a good marker of Mg status in rats. J. Nutr. 130: 2306-2311, 2000.
