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1
Cichota, R., I. Vogeler, N. S. Bolan e B. E. Clothier. "Cation influence on sulfate leaching in allophanic soils". Soil Research 45, n. 1 (2007): 49. http://dx.doi.org/10.1071/sr06070.
Testo completoAbstract (sommario):
We have examined the influence of the ionic composition of the soil solution on the movement of sulfate and calcium in 2 New Zealand soils with differing allophane content. For this study, we have carried out a series of miscible displacement experiments using repacked and intact soil columns, in which sulfate was applied in the presence of either calcium or potassium as the accompanying cation. Our results showed that sulfate leaching was significantly retarded in the soil with higher allophane content when applied with calcium. On the other hand, no effects were observed for all studied soils when potassium was used as the accompanying cation. In addition, in soils with high allophane content, calcium also had its retention increased when sulfate was present. The increase in sulfate adsorption was accompanied by corresponding increase in calcium adsorption. These findings evidenced the presence of co-adsorption, or ion-pair adsorption (IPA), in allophane-containing soils. The extent of this adsorption is dependent on the soil pH, the accompanying cation, and the allophane content of the soil.
2
Rogóż, Antoni, e Monika Tabak. "Contents of selected macroelements in soils, potatoes and fodder beets at variable soil reaction / Zawartość wybranych makroelementów w glebach oraz w ziemniakach i burakach pastewnych przy zmiennym odczynie gleby". Soil Science Annual 66, n. 1 (1 marzo 2015): 3–9. http://dx.doi.org/10.1515/ssa-2015-0012.
Testo completoAbstract (sommario):
Abstract The aim of the research was to determine the concentration of selected macroelements in soil and in root crops (potatoes and fodder beets) at a variable soil reaction. The changes in pH values in the studied soils influenced the content of these elements in soluble forms determined in 0.1 mol HCl·dm-3. A statistical analysis showed a positive relationship between the soil pH value and the calcium and magnesium contents in a form close to the total form, as well as the content of soluble forms of phosphorus, calcium, and magnesium. The content of the studied macroelements, i.e. phosphorus, calcium, magnesium in the cultivated fodder beets and potatoes depended on abundance and form in which the studied elements occurred in soil, and also on specie and analyzed part of the plant. Along with the increase in pH values of the an increase in the phosphorus content and reduction of the magnesium content in the roots and above-ground parts of the beets were found. The calcium content in the roots increased along with an increase in pH of the soils, whereas direction of changes in the content of this element in the petioles and laminae of the beets was not unambiguous. A slight decrease in the content of the studied elements in the potato tubers (along with the increase in pH of the soils) was found.
3
Yildiz, Ercan, Mehmet Yaman e Ahmet Sümbül. "RELATIONSHIPS BETWEEN PHYSICAL AND CHEMICAL PROPERTIES OF SOILS AND PLANT NUTRIENT CONTENT OF LEAVES IN THE APPLE ORCHARDS". Current Trends in Natural Sciences 11, n. 21 (31 luglio 2022): 139–44. http://dx.doi.org/10.47068/ctns.2022.v11i21.016.
Testo completoAbstract (sommario):
This study was carried out in 42 orchards located in the lowland of Develi, where the apple cultivation is intense in Kayseri province. The analyses were made to determine pH, CaCO3, EC, organic matter, available phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), iron (Fe), zinc (Zn), manganese (Mn) and copper (Cu) in soil samples and nitrogen (N), P, K, Ca, Mg, Fe, Zn, Mn, Cu, and boron (B) in leaf samples. In the study, the relationships between some physical and chemical properties of the soils and the plant nutrient content of the leaves were evaluated by correlation analysis. In the study, between some physical and chemical properties of soils and the nutritional elements of soils and leaves were found important statistical relations. These relationships were mostly between soil samples rather than leaves. On the other hand, the pH and EC values of the soils showed less significant relationships with the nutrient contents of the samples according to the organic matter and CaCO3 contents of soils. It was determined that the organic matter content of the soils had a positive relationship with all the investigated elements except phosphorus. It has been determined that the relationship between the CaCO3 content and nutritional elements in the soils is statistically significant, it has a positive correlation with potassium and calcium and a negative correlation with other investigated elements. No significant relationships were found between the nutrient contents of the soils and the macro element contents of the leaves. While some important statistical relationships were determined between nutrient contents of the soils and micro element contents of the leaves, the highest correlation was determined between copper and boron contents. It was determined that the copper content of the leaves was positively related to the phosphorus, potassium and magnesium content of the soils and negatively related to the manganese content of the soils.
4
PEKCAN, Tülin, Bihter ÇOLAK ESETLİLİ, Hatice Sevim TURAN e Erol AYDOĞDU. "Determination of Nutritional Status of Northwest Anatolia (North Aegean) Olive Growing Areas". MAS Journal Of Applied Sciences 7, n. 11 (10 marzo 2022): 210–20. http://dx.doi.org/10.52520/masjaps.221.
Testo completoAbstract (sommario):
The study was carried out to determine the productivity of olive plantations in 8 different districts of The North Aegean Region. For this purpose, soil and leaf samples were taken simultaneously from 26 different olive groves. 69.23% of the investigated surface soils (0-30 cm) are sandy loam, and 57.69% of the subsurface soils (30-60 cm) are sandy loam. It was determined that more than 50% of the soils were slightly alkaline and the lime contents were low at both depths. It is seen that the organic matter contents of 11% of the surface soils and 8% of the subsurface soils are low. Nitrogen contents at both depths are in the low class 38.46%. The available phosphorus contents of 23.08% of the surface soils and 11.54% of the subsurface soils are sufficient. Available potassium and calcium contents in all surface soils are sufficient. It was determined that the potassium content in 34.61% of the subsurface soils and the calcium content in 53.84% of the subsurface soils were sufficient and very high. It was determined that the available Mg content in 61.54% of the surface soil and 57.69% of the subsurface soil, was sufficient and very high. Sodium contents were determined adequately at both depths. When the leaf macro and secondary elements were examined according to the sufficiency limit values 46.15% of N, 26.92% of Ca 3.8% of Mg, and all the P and K contents, were found to be sufficient. of the microelements, 42.31% of B, 76.92% of Fe, 46.15% of Mn and 38.46% of Zn are sufficient. Considering the results of the study, it is recommended to make fertilizer recommendation based on the results of soil and leaf analysis in parallel with the regular cultural practices in order to obtain quality and high yield in North Aegean sustainable olive cultivation.
5
Al-Tarbouli, Nameer Hamed Yassin. "Adsorption and physicochemical release of iron ions in soils with different content of Calcium Carbonate and Calcium Sulfate". Tikrit journal for agricultural sciences 22, n. 3 (30 settembre 2022): 137–47. http://dx.doi.org/10.25130/tjas.22.3.16.
Testo completoAbstract (sommario):
Three soils of different content of gypsum and lime were selected, the first soil (G1) and the second soil (G3), were obtained near the fields of the Faculty of Agriculture, Tikrit University. As for the third soil (G5), was taken from the AL- alam Village side east of Tikrit city to a depth of (0-10)cm. the proportions of gypsum were 5%, 15%, 25%, and the proportions of lime were 25%, 20%, and 10% for soils G1, G3, and G5, respectively. Ferrous sulfate was added as a source of iron ions added to the three soils in the following proportions (0,10,25,50,100,150,250,500,750) mg.L-1 The concepts of isotherm were tested by using the physicochemical Freundlich and Langmuir adsorption equations. The results of the study showed the success of both equations in describing of iron ion adsorption process for all three soils, because They achieve a high (R2) but Langmuir's equation showed a greater superiority due to its decreasing (SE). As it appears from the results of the study, the superiority of treatment (G1) over treatments (G3) and (G5) in the maximum adsorption values, binding energy, (PBCFe)(KG) and (Kd) for adsorption and release. As for the values of Labale iron, the lowest value was in treatment (G1)then it began to increase until it reached its value in treatment (G5). The (Δf) values for the three soils were positive, and that the highest value was in soil (G1), and starts declining to reach its value for soil (G5).
6
Han, Guilin, Anton Eisenhauer, Jie Zeng e Man Liu. "Calcium Biogeochemical Cycle in a Typical Karst Forest: Evidence from Calcium Isotope Compositions". Forests 12, n. 6 (25 maggio 2021): 666. http://dx.doi.org/10.3390/f12060666.
Testo completoAbstract (sommario):
In order to better constrain calcium cycling in natural soil and in soil used for agriculture, we present the δ44/40Ca values measured in rainwater, groundwater, plants, soil, and bedrock samples from a representative karst forest in SW China. The δ44/40Ca values are found to differ by ≈3.0‰ in the karst forest ecosystem. The Ca isotope compositions and Ca contents of groundwater, rainwater, and bedrock suggest that the Ca of groundwater primarily originates from rainwater and bedrock. The δ44/40Ca values of plants are lower than that of soils, indicating the preferential uptake of light Ca isotopes by plants. The distribution of δ44/40Ca values in the soil profiles (increasing with soil depth) suggests that the recycling of crop-litter abundant with lighter Ca isotope has potential effects on soil Ca isotope composition. The soil Mg/Ca content ratio probably reflects the preferential plant uptake of Ca over Mg and the difference in soil maturity. Light Ca isotopes are more abundant in mature soils than nutrient-depleted soils. The relative abundance in the light Ca isotope (40Ca) is in the following order: farmland > burnt grassland > forests > grassland > shrubland. Our results further indicate that biological fractionation in a soil–plant system is a vital factor for Ca–geochemical transformations in soil surface systems.
7
Loveland, P. J., J. Hazelden e R. G. Sturdy. "Chemical properties of salt-affected soils in north Kent and their relationship to soil instability". Journal of Agricultural Science 109, n. 1 (agosto 1987): 1–6. http://dx.doi.org/10.1017/s0021859600080904.
Testo completoAbstract (sommario):
SummarySoil instability, as measured by the dispersion ratios of the reclaimed salt-marsh soils of ca. 70 km2 of north Kent, was assessed on samples taken from 0–15, 35–50 and 70–85 cm depths from sites at the intersects of a 250 m square grid or along transects. The dispersion ratios were related to other soil properties including exchangeable sodium, potassium and magnesium percentages, organic carbon content, calcium carbonate content and electrical conductivity. The dispersion ratio correlates most closely with exchangeable sodium percentage and organic carbon content; weaker correlations exist with exchangeable potassium and calcium carbonate contents. Dispersion ratios rise sharply, i.e. reflect a marked increase in soil instability, when organic carbon content is less than 2·5% and calcium carbonate content is less than 2%. Magnesium has little effect on the dispersion ratio. The soil solution salt concentration (as expressed by electrical conductivity) is too low over much of the area to promote flocculation, and hence stability, of the soil clays.
8
Neff, J. C., J. W. Harden e G. Gleixner. "Fire effects on soil organic matter content, composition, and nutrients in boreal interior Alaska". Canadian Journal of Forest Research 35, n. 9 (1 settembre 2005): 2178–87. http://dx.doi.org/10.1139/x05-154.
Testo completoAbstract (sommario):
Boreal ecosystems contain a substantial fraction of the earth's soil carbon stores and are prone to frequent and severe wildfires. In this study, we examine changes in element and organic matter stocks due to a 1999 wildfire in Alaska. One year after the wildfire, burned soils contained between 1071 and 1420 g/m2 less carbon than unburned soils. Burned soils had lower nitrogen than unburned soils, higher calcium, and nearly unchanged potassium, magnesium, and phosphorus stocks. Burned surface soils tended to have higher concentrations of noncombustible elements such as calcium, potassium, magnesium, and phosphorus compared with unburned soils. Combustion losses of carbon were mostly limited to surface dead moss and fibric horizons, with no change in the underlying mineral horizons. Burning caused significant changes in soil organic matter structure, with a 12% higher ratio of carbon to combustible organic matter in surface burned horizons compared with unburned horizons. Pyrolysis gas chromatography mass spectroscopy also shows preferential volatilization of polysaccharide-derived organic matter and enrichment of lignin- and lipid-derived compounds in surface soils. The chemistry of deeper soil layers in burned and unburned sites was similar, suggesting that immediate fire impacts were restricted to the surface soil horizon.
9
Elisa, A. A., S. Ninomiya, J. Shamshuddin e I. Roslan. "Alleviating aluminium toxicity on an acid sulphate soils in Peninsular Malaysia with application of calcium silicate". Solid Earth Discussions 7, n. 4 (19 ottobre 2015): 2903–26. http://dx.doi.org/10.5194/sed-7-2903-2015.
Testo completoAbstract (sommario):
Abstract. A study was conducted to alleviate Al toxicity of an acid sulphate soils collected from paddy cultivation area in Kedah, Peninsular Malaysia. For this purpose, the collected acid sulphate soils were treated with calcium silicate. The treated soils were incubated for 120 days in submerged condition in a glasshouse. Subsamples were collected every 30 days throughout the incubation period. Soil pH and exchangeable Al showed positive effect; soil pH increased from 2.9 to 3.5, meanwhile exchangeable Al was reduced from 4.26 to 0.82 cmolc kg−1, which was well below the critical Al toxicity level for rice growth of 2 cmolc kg−1. It was noted that the dissolution of calcium silicate (CaSiO3) supplied substantial amount of Ca2+ and H4SiO42− ions into the soil, noted with increment in Si (silicate) content from 21.21 to 40 mg kg−1 at day 30 and reduction of exchangeable Al at day 90 from 4.26 to below 2 cmolc kg−1. During the first 60 days of incubation, Si content was positively correlated with soil pH, while the exchangeable Al was negatively correlated with Si content. It is believed that the silicate anions released by calcium silicate were active in neutralizing H+ ions that governs the high acidity (pH 2.90) of the acid sulphate soils. This scenario shows positive effect of calcium silicate to reduce soil acidity, therefore creates a favourable soil condition for good rice growth during its vegetative phase (30 days). Thus, application of calcium silicate to alleviate Al toxicity of acid sulphate soils for rice cultivation is a good soil amendment.
10
Zhong, Yuqing, Guanghua Cai, Shiquan Wang, Huajin Qin, Caihong Zhang e Jiangshan Li. "Influence of Organic Content on the Mechanical Properties of Organic-Rich Soils Stabilized with CaO-GGBS Binder and PC". Water 14, n. 19 (28 settembre 2022): 3053. http://dx.doi.org/10.3390/w14193053.
Testo completoAbstract (sommario):
Organic-rich soil is a typical special soil often encountered in foundation treatment. Previous research has revealed that Portland cement (PC) not only pollutes the environment but is significantly affected by organic matter during its hydration and cementation. Although quicklime (CaO)-GGBS binder (CG) is an effective alternative to PC, its efficiency in treating organic-rich soils has not been studied. In this study, organic-rich soil was treated with two binders of CG and PC. The physical, mechanical, and chemical characteristics of the stabilized soils were tested at various organic contents, binder contents, and curing ages. The results show that the cracks in two treated soils increase with the increase in organic content and the reduction in binder content. CG-treated soils are more likely to shed big lumps after damage than PC-treated soils. The unconfined compressive strength (qu) and deformation modulus (E50) of stabilized soils increase with the increasing curing age and binder content but the decreasing organic content. The E50 of PC-treated soil is about 22~73 times qu, and the E50 of CG-treated soil shows an excellent linear relationship with qu. The moisture content of two treated soils increases as the organic content grows, but it falls as the curing age and binder content increase. The soil pH rises with the increasing organic content and binder content, but it declines with increased curing age. The strength development of organic-rich soils treated by the CG binder has an evident attenuation with the organic content. Given its possible environmental benefit, alkali (especially low calcium)-activated binder is appropriate for practical engineering with modest strength needs.
11
Adeleke, Blessing, John Kinuthia e Jonathan Oti. "Strength and Swell Performance of High-Sulphate Kaolinite Clay Soil". Sustainability 12, n. 23 (5 dicembre 2020): 10164. http://dx.doi.org/10.3390/su122310164.
Testo completoAbstract (sommario):
Expansion of soils has been found to produce significant negative economic and environmental impact on various civil engineering infrastructure. This impact is more deleterious in soils containing sulphates, when treated with calcium-based stabilizers such as Lime and/or Portland cement (PC). The reported study investigated the strength and swell characteristics of Kaolinite clay artificially induced with high levels of Gypsum (sulphate) contents after stabilization with CEM I (PC), which is a calcium-based stabilizer. An optimum stabilizer content/Gypsum dosage, aimed at investigating the maximum magnitude of expansion possible using high levels of 10, 15 and 20% Gypsum contents (4.7, 7 and 9.3 wt.% sulphate) stabilized with calcium-based content of 7, 8, 9 and 10 wt.%. This was expected to provide further understanding on the mechanisms behind high sulphate-bearing clay soils, and the impact of sulphate and calcium content on strength and swell characteristics. The research outcomes showed that the introduction of sulphate to a Kaolinite clay soil reduces the compressive strength of the stabilised product by a factor range of 6–47% at 28 days curing age, while the swell behaviour is mainly dependent on both the sulphate content and curing age. Furthermore, the observed result suggests an 8 wt.% binder content to produce maximum magnitude of expansion (swell) with a high Gypsum content of 10% by weight. This finding is of economic importance, as it is expected to serve as a benchmark for further research on the stabilized clay systems, at high sulphate levels using sustainable binder materials.
12
Mohammadi, Shima. "Employment of chemical autography method based on ion-exchange membranes for estimation of content of extracted cations within field conditions". АгроЭкоИнфо 1, n. 49 (5 febbraio 2022): 12. http://dx.doi.org/10.51419/202121112.
Testo completoAbstract (sommario):
The executed work supposed estimation of movable cations content in soils within soil of undestroyed structure in field conditions by employment of cation and ion-exchange membranes of MK-40 and MA-ЭДТА types. It is discovered that when increasing humus content and cultivation state of soddy podzolic soils the share of positively charged calcium becomes lower. At Сa Ln+/Ca Ln- from 0,7 up to 0,003; Мg from 0.22 to 0,08. So, MA-ЭДТА type membrane in comparison with MK-H membrane absorbs more calcium than Mg, Fe in comparison with Mn and especially calcium in comparison with K. Keywords: SOIL, MOVABLE CATIONS, ION-EXCHANGE MEMBRANES
13
Liu, Hailong, Jiuye Zhao, Yu Wang, Nangai Yi e Chunyi Cui. "Strength Performance and Microstructure of Calcium Sulfoaluminate Cement-Stabilized Soft Soil". Sustainability 13, n. 4 (20 febbraio 2021): 2295. http://dx.doi.org/10.3390/su13042295.
Testo completoAbstract (sommario):
Calcium sulfoaluminate cement (CSA) was used to stabilize a type of marine soft soil in Dalian China. Unconfined compressive strength (UCS) of CSA-stabilized soil was tested and compared to ordinary Portland cement (OPC); meanwhile the influence of amounts of gypsum in CSA and cement contents in stabilized soils on the strength of stabilized soils were investigated. X-ray diffraction (XRD) tests were employed to detect generated hydration products, and scanning electron microscopy (SEM) was conducted to analyze microstructures of CSA-stabilized soils. The results showed that UCS of CSA-stabilized soils at 1, 3, and 28 d firstly increased and then decreased with contents of gypsum increasing from 0 to 40 wt.%, and CSA-stabilized soils exhibited the highest UCS when the content of gypsum equaled 25 wt.%. When the mixing amounts of OPC and CSA were the same, CSA-stabilized soils had a significantly higher early strength (1 and 3 d) than OPC. For CSA-stabilized soil with 0 wt.% gypsum, monosulfate (AFm) was detected as a major hydration product. As for CSA-stabilized soil with certain amounts of gypsum, the intensity of ettringite (Aft) was significantly higher than that in the sample hydrating without gypsum, but a tiny peak of AFm also could be detected in the sample with 15 wt.% gypsum at 28 d. Additionally, the intensity of AFt increased with the contents of gypsum increasing from 0 to 25 wt.%. When contents of gypsum increased from 25 to 40 wt.%, the intensity of AFt tended to decrease slightly, and residual gypsum could be detected in the sample with 40 wt.% gypsum at 28 d. In the microstructure of OPC-stabilized soils, hexagonal plate-shaped calcium hydroxide (CH) constituted skeleton structures, and clusters of hydrated calcium silicates (C-S-H) gel adhered to particles of soils. In the microstructure of CSA-stabilized soils, AFt constituted skeleton structures, and the crystalline sizes of ettringite increased with contents of gypsum increasing; meanwhile, clusters of the aluminum hydroxide (AH3) phase could be observed to adhere to particles of soils and strengthen the interaction.
14
Diomandé, L. B., G. R. Soro, S. Soro e Et Yao Kouamé A. "CHEMICAL SOIL FERTILITY DIAGNOSIS FOR COTTON CROPPING IN NORTHERN COTE D'IVOIRE". International Journal of Research -GRANTHAALAYAH 9, n. 8 (31 agosto 2021): 27–34. http://dx.doi.org/10.29121/granthaalayah.v9.i8.2021.4130.
Testo completoAbstract (sommario):
The work was conducted in the north of Cote d’Ivoire, central pivot cotton production savannah area, to make the diagnosis of soil fertility for cotton cropping. Cotton cropping, the mainstay of the savannah's economy, suffered from low productivity in relation to the soils chemical properties. Prior cultivation, soils samples were collected at a depth of 0 to 30 cm, collecting 32 simple samples to generate a complete sample. The samples were sent to the soil laboratory to measure the pH unities, CEC, nitrogen, phosphorus, potassium, calcium, magnesium, sodium, iron, zinc, copper and manganese contents. In order to facilitate the interpretation of analysis results, the nutrients critical level recommended for optimum production of cotton were used. Results showed that soils had pH ranging from 4.4 to 6.4. On the other hand, the need to add nitrogen, magnesium and phosphorus to the soils and to augment the low carbon, calcium and potassium content. There is the need to search for fertilizer formulations with nitrogen, magnesium phosphorus and calcium for the Cote d'Ivoire cotton belt.
15
Clough, A., e J. O. Skjemstad. "Physical and chemical protection of soil organic carbon in three agricultural soils with different contents of calcium carbonate". Soil Research 38, n. 5 (2000): 1005. http://dx.doi.org/10.1071/sr99102.
Testo completoAbstract (sommario):
The amount of organic carbon physically protected by entrapment within aggregates and through polyvalent cation–organic matter bridging was determined on non-calcareous and calcareous soils. The composition of organic carbon in whole soils and <53 m soil fractions was determined by 13C NMR analysis. High energy photo-oxidation was carried out on <53 m fractions and results from the NMR spectra showed 17–40% of organic carbon was in a condensed aromatic form, most likely charcoal (char). The concept that organic material remaining after photo-oxidation may be physically protected within aggregates was investigated by treating soils with a mild acid prior to photo-oxidation. More organic material was protected in the calcareous than the non-calcareous soils, regardless of whether the calcium occurred naturally or was an amendment. Acid treatment indicated that the presence of exchangeable calcium reduced losses of organic material upon photo-oxidation by about 7% due to calcium bridging. These results have implications for N fertiliser recommendations based upon organic carbon content. Firstly, calcium does not impact upon degradability of organic material to an extent likely to affect N fertiliser recommendations. Secondly, standard assessment techniques overestimate active organic carbon content in soils with high char content.
16
Elisa, A. A., S. Ninomiya, J. Shamshuddin e I. Roslan. "Alleviating aluminum toxicity in an acid sulfate soil from Peninsular Malaysia by calcium silicate application". Solid Earth 7, n. 2 (9 marzo 2016): 367–74. http://dx.doi.org/10.5194/se-7-367-2016.
Testo completoAbstract (sommario):
Abstract. In response to human population increase, the utilization of acid sulfate soils for rice cultivation is one option for increasing production. The main problems associated with such soils are their low pH values and their associated high content of exchangeable Al, which could be detrimental to crop growth. The application of soil amendments is one approach for mitigating this problem, and calcium silicate is an alternative soil amendment that could be used. Therefore, the main objective of this study was to ameliorate soil acidity in rice-cropped soil. The secondary objective was to study the effects of calcium silicate amendment on soil acidity, exchangeable Al, exchangeable Ca, and Si content. The soil was treated with 0, 1, 2, and 3 Mg ha−1 of calcium silicate under submerged conditions and the soil treatments were sampled every 30 days throughout an incubation period of 120 days. Application of calcium silicate induced a positive effect on soil pH and exchangeable Al; soil pH increased from 2.9 (initial) to 3.5, while exchangeable Al was reduced from 4.26 (initial) to 0.82 cmolc kg−1. Furthermore, the exchangeable Ca and Si contents increased from 1.68 (initial) to 4.94 cmolc kg−1 and from 21.21 (initial) to 81.71 mg kg−1, respectively. Therefore, it was noted that calcium silicate was effective at alleviating Al toxicity in acid sulfate, rice-cropped soil, yielding values below the critical level of 2 cmolc kg−1. In addition, application of calcium silicate showed an ameliorative effect as it increased soil pH and supplied substantial amounts of Ca and Si.
17
Pukish, Arsen. "STUDY OF THE RESTORATION FEATURES OF SOILS THAT WERE INFLUENCED BY FORMATION WATERS". Scientific Bulletin Series D : Mining, Mineral Processing, Non-Ferrous Metallurgy, Geology and Environmental Engineering 31, n. 2 (2017): 71–76. http://dx.doi.org/10.37193/sbsd.2017.2.10.
Testo completoAbstract (sommario):
The article presents the studies results on the restoration of saline soils affected by formation waters. Soil restoration was carried out using solutions of various water-soluble salts. The author determined that treatment of saline soils with a solution of magnesium sulfate at a concentration of 0,3 mol/dm3 helps to decrease the content of chlorides, sodium, calcium, while the content of magnesium and sulfates increases, but the total content of toxic salts in the soil decreases by 60,9%.
18
FUJIMORI, Yuichi, Masaharu FUKUE, Yoshihisa KATO, Kazuo MASUBUCHI e Takuya SASAJIMA. "SEDIMENTOLOGY BASED ON CALCIUM CARBONATE CONTENT FOR ALLUVIAL SOILS". Doboku Gakkai Ronbunshuu C 63, n. 4 (2007): 1163–74. http://dx.doi.org/10.2208/jscejc.63.1163.
Testo completo
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Choi, Sun-Gyu, Sung-Sik Park, Shifan Wu e Jian Chu. "Methods for Calcium Carbonate Content Measurement of Biocemented Soils". Journal of Materials in Civil Engineering 29, n. 11 (novembre 2017): 06017015. http://dx.doi.org/10.1061/(asce)mt.1943-5533.0002064.
Testo completo
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Tonkha, O., O. Bukova, O. Pikovska, I. Fedosiy, O. Menshov e A. Shepel. "SILICON CONTENT, PHYSICAL AND CHEMICAL PROPERTIES OF SOILS OF THE KHMELNYTSKY REGION OF UKRAINE". Visnyk of Taras Shevchenko National University of Kyiv. Geology, n. 3 (90) (2020): 85–90. http://dx.doi.org/10.17721/1728-2713.90.12.
Testo completoAbstract (sommario):
Silicon plays the significant role in the growth and development of plants, their resistance to stress conditions. However, there is limited research on the content of various forms of silicon in soils, the relationship with soil cations, which is particularly relevant in the context of intensive agriculture and climate aridization in Ukraine. The purpose of the present study was to determine the content of silicon compounds of different mobility in the arable soils of the Khmelnytsky region, the spatial variation of these parameters, and to detect the dependence between the content of silicon compounds and soil particle size. The study was performed at the area of LLC "Lotivka Elit" of Shepetivka district of Khmelnitsky region in field crop rotation. We determined for soil samples: particle size distribution and content of fractions of granulometric elements of different sizes, pH of salt extraction (1,0 M KCl solution), humus content, calcium and magnesium exchangeable compounds by extraction with 1,0 M KCl solution. The results showed that the content of silicon compounds in soils depends on the particle size distribution of soil, the value of exchangeable acidity, humus content, and the composition of exchangeable cations.
21
Dai, Lei, e Xiao Xuan Deng. "The Relationship between Calcium Hydroxide Concentration in Pore Solution and the Strength of Stabilized Soils". Advanced Materials Research 989-994 (luglio 2014): 19–22. http://dx.doi.org/10.4028/www.scientific.net/amr.989-994.19.
Testo completoAbstract (sommario):
Under the same cement content, the stabilized soils, made of the soils with similar physical properties, may be significant difference in the strength. In this research, three groups of soils were selected, and the soils in each group are similar in physical properties. Strength and ions concentration in pore solution of the stabilized soils were investigated. The result reveals that calcium hydroxide (CH) concentration in pore solution of the stabilized soils might not reach to saturation due to soil consuming Ca2+and thus cause calcium silicate hydrates gels (C-S-H) and calcium aluminates hydrates gels (C-A-H) to form less. The cementitious hydrates are the main strength contributors of the stabilized soils. The Strengths of stabilized soils, the soils bearing similar physical properties, were almost identical as long as the CH concentrations in pore solution were saturated. The effect of chemical factors of soil on the strength of stabilized soil can be briefly attributed to the change of CH concentration in pore solution, and be further attributed to the influence of CH concentration on the amount of C-S-H and C-A-H formed in stabilized soils.
22
Kosiorek, Milena, e Mirosław Wyszkowski. "Macroelement content in plants after amendment application to cobalt-contaminated soil". Journal of Soils and Sediments 21, n. 4 (26 febbraio 2021): 1769–84. http://dx.doi.org/10.1007/s11368-021-02907-0.
Testo completoAbstract (sommario):
Abstract Aim The study was undertaken to determine the effect of amendments used in remediation of cobalt-contaminated soil on the macroelement content of all organs of spring barley (the main crop) and white mustard (the after-crop). Methods In the experiment, six blocks were selected: without amendments; with manure (bovine, granulated); clay; charcoal; zeolite; and with calcium oxide (50%). In each of the blocks, increasing doses of cobalt were applied: 0, 20, 40, 80, 160, and 320 mg kg−1 of soil. Results Cobalt-contaminated soil and amendments application had a significant effect on macroelement content of all organs of both plants. Conclusions In blocks without amendments, 80 mg Co kg−1 contributed the most increase in nitrogen, sodium, and calcium contents of both organs of spring barley. Cobalt-contaminated soil increased content of all macroelements in white mustard organs. Application of amendments to soil had strong impact on phosphorus, sodium, and calcium contents of organs of both plant species, compared to the control block (without amendments). Among the amendments, manure had the greatest effect on the content of macroelements in plants. Manure increased phosphorus, potassium, and sodium contents of all organs of both plants. The optimal content of macroelements is extremely important for the growth and development of plants, especially on soils contaminated with trace elements, including cobalt.
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Zheng, Xuefang, Bo Liu, Yujing Zhu, Jieping Wang, Haifeng Zhang e Ziran Wang. "Bacterial community diversity associated with the severity of bacterial wilt disease in tomato fields in southeast China". Canadian Journal of Microbiology 65, n. 7 (luglio 2019): 538–49. http://dx.doi.org/10.1139/cjm-2018-0637.
Testo completoAbstract (sommario):
Tomato bacterial wilt caused by Ralstonia solanacearum is a devastating plant disease. The aims of this study were to investigate the relationship among soil nutrients, rhizobacterial community, and abundance of R. solanacearum, and to gather useful information for controlling the disease. Fifteen tomato rhizosphere soils were collected from three regions, encompassing five disease grades. Then, soil physicochemical properties and rhizobacterial communities were investigated. The content of soil organic carbon (SOC), total phosphorus (TP), total potassium (TK), and exchangeable calcium was significantly higher in the healthy plant rhizosphere soils than in diseased plant rhizosphere soils (P < 0.05). The healthy soils had a relatively higher abundance of Proteobacteria and a lower abundance of Acidobacteria than the diseased soils from the same region. Redundancy analysis demonstrated that R. solanacearum abundance was positively correlated with total nitrogen content and negatively correlated with soil pH, SOC, TP, TK, and exchangeable calcium. Ralstonia solanacearum abundance correlated positively with Chloroflexi, Acidobacteria, and Planctomycetes abundance but negatively with Nitrospirae, Bacteroidetes, and Proteobacteria abundance. These results suggested that improving soil pH, applying the amount of P and K fertilizers, and controlling the dosage of N fertilizer might be an effective approach in controlling bacterial wilt disease.
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Liljestrand, H. M., e S. M. Parten. "Design of On-Site Treatment Systems in Caliche Soils". Water Science and Technology 28, n. 10 (1 novembre 1993): 83–87. http://dx.doi.org/10.2166/wst.1993.0210.
Testo completoAbstract (sommario):
Caliche soils, weathered limestone soils of high calcium carbonate content and and low organic content, are common in regions with limestone sedimentary geology and arid to semi-arid climate. Currently, there are no standards other than hydraulic soil properties for the design and construction of on-site wastewater treatment systems in caliche soils. Experimental studies were performed to investigate biological transformation rates for organic carbon to inorganic carbon and organic nitrogen to nitrate, using four different caliche soils and the range of recommended hydraulic loading rates. The experimental results indicate that oxygen demanding materials readily decay over short distances in caliche soils. Efficiency of removal for TOC was >97%. However in three of the four caliche soils, nitrate concentrations were significantly higher than the background and the control cases. The high calcium carbonate content of the caliche soils leads to solutions well buffered with respect to pH and alkalinity. Nitrification rates are very rapid in these soils which are buffered at the optimum pH range for Nitrosomonas growth. The low organic carbon content of caliche soils results in low denitrification rates. Nitrate in the effluent is the limiting pollutant in the determination of appropriate loading rates, drain field area, and land requirements. Phosphate and metal aqueous concentrations are acceptably low and are limited by solubility control in the open system equilibrium model.
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Barzegar, AR, RS Murray, GJ Churchman e P. Rengasamy. "The strength of remolded soils as affected by exchangeable cations and dispersible clay". Soil Research 32, n. 2 (1994): 185. http://dx.doi.org/10.1071/sr9940185.
Testo completoAbstract (sommario):
The tensile strengths of remoulded samples of five Australian soils with differing clay type, texture and shrink-swell potential were measured as a function of exchangeable cations (Na, Ca and Mg) and exchangeable sodium percentage (ESP). Spontaneously and mechanically dispersible clays were also determined as a function of ESP. The tensile strength changed with the nature of the exchangeable cation, clay content and amounts of spontaneously and mechanically dispersible clay. In Ca-soils, the tensile strength was highly correlated with clay content and CEC. Regression analyses of data for soils containing various amounts of exchangeable sodium showed that mechanically and spontaneously dispersible clay were individually correlated with the tensile strength of remoulded soils. However, multiple regression analyses of these data indicated that spontaneously dispersible clay alone was a major predictor of the tensile strength of remoulded sodic soils. This suggests that measurement of spontaneously dispersible clay adequately accounts for the differences in tensile strengths of dry remoulded soils as influenced by ESP values. Analysis of variance of data for all the soils with varying ESP values showed that spontaneously dispersible clay was strongly correlated with clay content. Analyses of data for individual soil type showed that spontaneously dispersible clay was highly correlated with ESP. For each soil studied, increase in ESP resulted in increase of dispersible clay and hence in tensile strength. Although tensile strength increased with ESP, the rate of change of strength with ESP was different for each soil. Soil with the highest clay content gave rise to the greatest rate of change. The effect of exchangeable magnesium on tensile strength was similar to calcium. However, in two of the soils, exchangeable magnesium, in the presence of sodium, increased the strength slightly more than calcium, confirming the ionic radius effect of these elements.
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Olego, Miguel Ángel, Mateo D. Cuesta-Lasso, Fernando Visconti Reluy, Roberto López, Alba López-Losada e Enrique Garzón-Jimeno. "Laboratory Extractions of Soil Phosphorus Do Not Reflect the Fact That Liming Increases Rye Phosphorus Content and Yield in an Acidic Soil". Plants 11, n. 21 (27 ottobre 2022): 2871. http://dx.doi.org/10.3390/plants11212871.
Testo completoAbstract (sommario):
In addition to aluminum and other heavy metal toxicities, acidic soils also feature nutrient deficits that are not easily overcome by merely adding the required amounts of mineral fertilizers. One of the most critically scarce nutrients in acidic soils is phosphorus, which reacts with aluminum and iron to form phosphates that keep soil phosphorus availability significantly low. Liming ameliorates acidic soils by increasing pH and decreasing aluminum contents; however, it also increases the amount of calcium, which can react with phosphorus to form low-solubility phosphates. In the present work, three liming materials, namely, dolomitic limestone, limestone and sugar foam, were applied on a Typic Palexerult cropped with rye. The effects of these materials on soil properties, including soil available phosphorus extracted with the Olsen and Bray-1 methods, rye phosphorus content in stems and stem and spike harvested biomasses were monitored for nine years. According to the Olsen extraction, the amount of soil available phosphorus generally decreased following liming, with limestone presenting the lowest values; however, the amount of soil available phosphorus increased according to the Bray-1 extraction, though only to a significant extent with the sugar foam from the third year onward. Regardless, the phosphorus content in rye and the relative biomass yield in both stems and spikes generally increased as a consequence of liming. Since crop uptake and growth are the ultimate tests of soil nutrient availability, the inconsistent stem phosphorus content results following the Olsen and Bray-1 extraction methods suggest a lowered efficiency of both extractants regarding crops in soils rich in both aluminum and calcium ions. This decrease can lead to important interpretation errors in the specific conditions of these limed acidic soils, so other methods should be applied and/or researched to better mimic the crop roots’ phosphorus extraction ability. Consequently, the effects of the liming of acidic soils on phosphorus availability and crop performance in the short and long term will be better understood.
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Bonomelli, Claudia, Pilar M. Gil e Bruce Schaffer. "Effect of Soil Type on Calcium Absorption and Partitioning in Young Avocado (Persea americana Mill.) Trees". Agronomy 9, n. 12 (3 dicembre 2019): 837. http://dx.doi.org/10.3390/agronomy9120837.
Testo completoAbstract (sommario):
A two-year study was conducted to determine how soil texture affects calcium (Ca) absorption and partitioning in potted ‘Hass’ avocado trees. Trees were planted in 200 L pots in one of four soil types: clay (C), clay loam (CL), sandy loam (SL) or sand (S). Prior to planting, Ca content in each soil was in the normal range of availability, although the Ca concentration was highest in C soil. After two years of tree development, dry weights of shoots and roots were significantly higher in the SL and S soils than in C soil. Trees in the C soil had higher wood dry weight than trees in SL or S soils. The Ca contents (absolute quantities, not concentrations) in the roots, shoots and whole tree were significantly lower in the C soil than in the SL or S soils. The K/Ca ratio of trees in the C soil (K/Ca = 1.5) was significantly higher than that in the other soil types. Stem water potential was significantly lower for trees in the C soil compared to the other soils. These results indicate that Ca absorption and partitioning in young avocado trees varies with soil texture, probably associated with soil effects on root growth and/or plant water status.
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Humeniuk, H. B., V. O. Khomenchuk, N. G. Zinkovska e N. V. Moskalyuk. "ПОРІВНЯЛЬНА ХАРАКТЕРИСТИКА ВМІСТУ КАЛЬЦІЮ ТА СТУПЕНЯ КИСЛОТНОСТІ У ҐРУНТАХ ТЕРНОПІЛЬСЬКОЇ ОБЛАСТІ". Scientific Issue Ternopil Volodymyr Hnatiuk National Pedagogical University. Series: Biology 78, n. 4 (4 giugno 2020): 41–49. http://dx.doi.org/10.25128/2078-2357.19.4.7.
Testo completoAbstract (sommario):
The soils of Ukraine have been well studied, however this did not prevent them from the intensive degradation processes. About a third of the arable land is eroded, about 20% of organic matter is lost, almost all the arable land in the subsoil is compacted, the nutrient forms of mobile phosphorus and especially calcium are significantly reduced, calcium, occupying the bulk of the cation exchange capacity of the soil, serves as a regulator. Calcium is a coagulator of soil colloids, protects them from destruction and removal to the lower horizons of the profile; promotes the formation and preservation of humus and its stable compounds; creates proper physical conditions, plays a crucial role in structure formation; binds moving forms of compounds of aluminum, iron, manganese, which adversely affect the cultural vegetation. Calcium is also a direct nutrient of plants and soil microorganisms and plays an exclusive mobilizing role in soil, increasing the content of basic nutrients available to plants, primarily phosphorus.
In the work we carried out chemical assessment of soils of Kozova, Zboriv Shumsk, Pidhaytsi and Berezhany districts of Ternopil region. We also studied the acidity, content of exchangeable calcium and natural factors that determine the peculiarities of agricultural natural resource use and influence. Correlation relationships between the studied values are established.
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Ihsan Ramadhan, Payizan, e Lazkeen Ahmed Merween Mehmedany. "Zinc Adsorption in Different Calcareous Soils". Journal Of Duhok University 23, n. 2 (14 dicembre 2020): 118–30. http://dx.doi.org/10.26682/ajuod.2020.23.2.15.
Testo completoAbstract (sommario):
Zinc adsorption was studied for ten selective representative soils according the difference amount of clay content, calcium carbonate and organic matter in Duhok governorate, Iraqi-Kurdistan region included (Kanimasi-1&2, Batofa, Zakho, Assih, Semeel, Khanke, Faydi, Zawita and Bamarny locations). Samples were air dried and sieved through a 2-mm sieve to study the physical and chemical characteristics of the soils, forms of zinc and it’s adsorption. Results showed the soluble, DTPA extractable zinc (available), CaCl2 extractable zinc (exchangeable) and total zinc ranged between (0.29 – 0.94), (0.88 – 1.64), (1.71 – 2.05), and (12.25 – 56.15) mg kg-1 respectively. Negative significant correlation found between soluble zinc with pH, also negative significant correlation found between DTPA extractable zinc with exchangeable potassium, bicarbonate and available phosphorus but positive significant correlation found between CaCl2 extractable zinc with pH, total–Zn negatively affected with pH and positively with HCO3 and sand. Results demonstrated that by increasing added zinc concentration to studied soil zinc will be adsorbed zinc adsorbed greatly at temperature 25°C and 48°C. In general total zinc adsorbed at 25C° in six concentrations was less than zinc adsorbed at 48C°. At temperatures 25°C and 48°C the high total amount of zinc adsorbed found in the soil of Zawita and Zakho respectively, but the lower total zinc adsorbed observed in soil of Batofa and Kani masi-2. The quantity of adsorption affected positively by presence of clay, calcium carbonate, active calcium carbonate and cation exchange capacity and negatively affected by the ion concentration of bicarbonate, calcium, potassium, organic matter and sand content.
30
E.S., Koybakova, Mustafayev M.G. e Amanbaeva B.Sh. "Technological methods of improvement of degraded soils under the sowing of legumes and groat cultures of the South Kazakhstan". Ekologiya i stroitelstvo 2 (2016): 22–27. http://dx.doi.org/10.35688/2413-8452-2016-02-004.
Testo completoAbstract (sommario):
Kazakhstan currently faced with a serious deterioration in the state of natural resources and the environment in all the most important environmental indicators. Almost a third of the agricultural land is now degraded or is seriously threatened, and more than 10 million hectares of potentially arable land in the past has been abandoned. The article presents the results of research to improve the well-being of reclamation of soils of southern Kazakhstan. The studies were conducted in the field and in the lysimeters, with laying of experiments on the introduction of phosphogypsum and deep loosening. The results showed that the most promising is the option with the introduction of 5...7 t/ha of phosphogypsum and deep loosening in which the reduced alkalinity of soils, it improves soil alkalinity magnesium that is reduced magnesium content in the soil, increases the content of non-toxic salts and productivity of legumes. Soil application of phosphogypsum at the rate of 5 t/ha increase the calcium cations in the rooting zone of soils. On one of the variants of the experience as a result of using phosphogypsum norm 5 t/ha calcium content increased on 4.67 times. On option, where they grow soybeans, the calcium content amounted to 0.046 %. The introduction of phosphogypsum reduces the alkalinity of soils and reduces the amount of magnesium and increases the content of non-toxic salts СаЅО4, increases the yield of leguminous and cereal crops. Soybean yield in the control variant was 11.27 kg/ha. Soil application of phosphogypsum at the rate of 5 t/ha increased its yield is 31.4% compared to the control variant, the variant with deep loosening – 15.1 %. In the variant where the soil amended phosphogypsum and the deep tillage, soybean yields by 34.1 % higher than the control variant. Therefore, the proposed techniques improve the soil of magnesium solontsovaya the South of Kazakhstan are promising.
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Alleoni, Luís Reynaldo Ferracciú, Otávio Antonio de Camargo e José Maria Aires Silva Valadares. "CORRELATIONS BETWEEN HOT CALCIUM CHLORIDE-EXTRACTED BORON AND CHEMICAL AND PHYSICAL ATTRIBUTES OF SOME BRAZILIAN SOILS". Scientia Agricola 56, n. 2 (1999): 295–300. http://dx.doi.org/10.1590/s0103-90161999000200006.
Testo completoAbstract (sommario):
Relationship between soluble boron extracted with a hot CaCl2 0.01 mol L-1 solution and pH; organic carbon; exchangeable cations; cation exchange capacity (CEC); base saturation; total, free and amorphous iron and aluminum oxide contents; clay content; and specific surface area were performed for surface and subsurface samples of five soils. The soils were a Rhodic Hapludox, an Arenic Paleudalf and three Typic Hapludox, all representative soils of the State of São Paulo, Brazil. To quantify the relations between soluble boron and the different soil characteristics, simple linear correlations and multiple regressions, using a stepwise regression program, were performed. Hot-CaCl2 extractable boron (HCB) was significantly correlated with clay content (r = 0.69*), specific surface area (r = 0.68*), CEC (r = 0.63*) and total aluminum oxides (r = 0.70*) in all five soils. In addition, there was a correlation between HCB and organic carbon (r = 0.75*) in the four Oxisols. The correlation coefficient between the product (carbon x clay) and soluble boron contents was also highly significant (r = 0.78**). Multiple regression analysis showed that total aluminum oxide, as well as exchangeable calcium and aluminum, were correlated with HCB, explaining 85% of the variation. The product (carbon x clay) took into account the effect of textural gradient and showed high positive correlation with hot-CaCl2 0.01 mol L-1extractable boron.
32
Jakovljevic, Miodrag, Nikola Kostic e Svetlana Antic-Mladenovic. "The availability of base elements (Ca, Mg, Na, K) in some important soil types in Serbia". Zbornik Matice srpske za prirodne nauke, n. 104 (2003): 11–21. http://dx.doi.org/10.2298/zmspn0304011j.
Testo completoAbstract (sommario):
In this paper results are presented of agrochemical and mineralogical analyses of 14 types of important soils in Serbia (Vojvodina and Central Serbia) and total content and availability of base alkali elements (Ca, Mg Na, K) are determined. Total element content was as follows: Ca 2.22%; K 1.77%; Na 0.85% and Mg 0.61%. Total content of alkali metals in the soils investigated and their variations within and between the soil types, is in very good/close correlation with contents of primary and secondary minerals as well as their rates of weathering. Taking in account the average availabilities the most abundant is calcium with 947 mg/100 g, whilst the averages of the other elements (Mg, K and Na) are quite similar and are about of 40 mg/100 g of soil. The results obtained have shown that the soils investigated are well to moderate provided with K, Ca and Mg and that their deficit could not be expected in plant nutrition, apart for some plants/cultures in the case of magnesium due to occasionally higher Ca/Mg and K/Mg ratios.
33
Hossen, MAM, SA Lira, MY Mia e AKMM Rahman. "Soil Nutrient Status of Brahmaputra Floodplain Area in Tangail Sadar Upazila for Agricultural Uses". Journal of Environmental Science and Natural Resources 8, n. 2 (29 febbraio 2016): 11–14. http://dx.doi.org/10.3329/jesnr.v8i2.26856.
Testo completoAbstract (sommario):
Soil samples from high land, medium high land, medium low land and low land of Brahmaputra Floodplain area showed that pH of the soils were slightly acidic; organic matter (OM) content was medium; total nitrogen (N), available potassium (K) and boron (B) content were low; available phosphorus (P) content was very low; available sulfur (S) and calcium (Ca) content were medium to very high; magnesium (Mg) and zinc (Zn) content were low to optimum; copper (Cu), manganese (Mn) and iron (Fe) content were very high suggesting the fact that soils of this area is moderately suitable for agricultural uses.J. Environ. Sci. & Natural Resources, 8(2): 11-14 2015
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Navarro-Pedreño, Jose, María Almendro-Candel, Ignacio Gómez Lucas, Manuel Jordán Vidal, Jaume Bech Borras e Antonis Zorpas. "Trace Metal Content and Availability of Essential Metals in Agricultural Soils of Alicante (Spain)". Sustainability 10, n. 12 (1 dicembre 2018): 4534. http://dx.doi.org/10.3390/su10124534.
Testo completoAbstract (sommario):
This article analysed the presence of trace metals (essential elements and pollutants) and soil properties in rural abandoned soils of a Mediterranean region. The soil properties determined were texture, pH, equivalent calcium carbonate, soil organic matter, availability of micronutrients (Fe, Mn, Cu, and Zn), and acid microwave digestion extraction to measure the trace metals considered as main pollutants (Cu, Zn, Cd, Cr, Ni, and Pb). Descriptive statistics and correlations were used to determine the relations among these parameters. pH, soil organic carbon (SOC), and clay were the main properties that controlled the availability of essential metals. pH was the main factor related to these metals in these calcareous soils. However, SOC, which can be incremented by adding organic fertilizers for soil rehabilitation as a sustainable practice, played an important role. Mean values of the metal composition in soils (Cu, Zn, Cd, Cr, Ni, and Pb) obtained in this study were similar to values reported for other areas in the Mediterranean basin.
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Hasanov, R. G., G. S. Hasanov e V. K. Valiev. "NEUTRALIZATION OF PHENOL-CONTAMINATED SOILS". Chemical Problems 20, n. 2 (2022): 154–63. http://dx.doi.org/10.32737/2221-8688-2022-2-154-163.
Testo completoAbstract (sommario):
To eliminate the consequences of accidental spill of phenol, the results of neutralization of soils contaminated with phenol are presented. As for the analysis of soils by the geological-lithological section it was found that in areas of phenol contamination the soil has a surface soil-plant layer with a thickness of about 0.5m, then there is a heavy clay layer with a thickness of up to 7.0 m and finally a sand layer saturated with groundwater is observed. It revealed that according to physical and mechanical properties, the solid mineral phase of the soil corresponds to a hard plastic and semi-solid consistency of clays. It showed that the filtration of water through the bottom and walls on the area of the former burial of the tank is complicated because of closer to zero water permeability of soil strata due to clay rock. Mineralogical and chemical composition of soils contaminated with phenol is determined. An environmentally safe method of neutralizing phenol-containing soils is developed with a neutralizing composition based on quicklime and bentonite which simplifies the neutralization method of soils contaminated with phenol. Environmental safety was observed in the absence of phenol in water extracts from soils and the in treatment process permissible for the environment рН. Essence of proposed method lies in chemical inactivation of phenol based on its transformation into slow-moving water-insoluble compound - calcium phenolate. Decontamination product of phenol-containing soil is the smallest capsules comprising soil particles and immobilized phenol in the form of calcium phenolate. Material of the capsule represented by calcium hydroxide is neutralized over time by bentonite and СО2 from air resulting in the formation of hydrophobic silicate and calcium carbonate which gives capsules high strength properties. The research into the neutralized phenol containing soil for phenol in water extracts showed that the proposed method is simple, ecologically safe, causes no recontamination of environment with pollutants and provides the phenol content in soils within MAC.
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Klenov, Boris M., e Mikhail V. Yakutin. "CALCIUM IN SOIL HUMUS OF WEST-SIBERIAN TRANSECT". Interexpo GEO-Siberia 4, n. 2 (8 luglio 2020): 64–70. http://dx.doi.org/10.33764/2618-981x-2020-4-2-64-70.
Testo completoAbstract (sommario):
The paper analyzes the behavior of one of the main components of humus (humic acids - calcium system) depending on the participation of calcium in the biological cycle of substances. The role of calcium in the formation of ecological stability of humic systems is shown, which largely determines the environmentally sustainable agriculture. It is shown that the changeable calcium amounts to no more than a half of its total content in humus horizon of automorphic zonal soils. Within the limits of the transect, the participation of calcium in binding of humic and fulvic acids is distributed according to their content in humus composition. Additional assessment of exchangeable calcium content to be determined by nontraditional method showed the same geographic regularity of its distribution in the soils of the transect as in the case of distribution of the main characteristics of humus.
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Bahloul, Ouassila, Hocine Ziani e Samir Benmoussa. "Impact of Calcium Chloride on the Microstructure of a Collapsible Soil". Annales de Chimie - Science des Matériaux 46, n. 4 (31 agosto 2022): 201–6. http://dx.doi.org/10.18280/acsm.460405.
Testo completoAbstract (sommario):
The study of the collapse of soils under the effect of flooding is a major problem in soil mechanics. Most of the work done on the treatment of these soils has been devoted to the use of binders of hydraulic or organic types. However, little work has been devoted to the use of salt calcium chloride in collapsible soil treatments. The purpose of this study is to evaluate the effect salt calcium chloride on a reconstituted collapsible soil in the laboratory, at different levels of water content, compaction energy and concentration of the saline solution. The results obtained showed a significant reduction in the potential for soil deformation and an illustration and a noticeable interaction between the soil particles and the saline solution resulting in a denser material.
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Jaworska, Hanna, Agata Bartkowiak e Szymon Różański. "The influence of anthropogenically increased pH on the content and the mobility of nickel in arable soils in the surroundings of “Małogoszcz” cement plant". Soil Science Annual 64, n. 1 (1 giugno 2013): 14–18. http://dx.doi.org/10.2478/ssa-2013-0003.
Testo completoAbstract (sommario):
Abstract The aim of the conducted research was the evaluation of the influence of increased pH on the content and mobility of nickel in arable soils in the surroundings of Małogoszcz Cement Plant. The physico-chemical properties of the investigated soils were determined by the methods commonly used in soil laboratories. The total content of Ni was determined after mineralization in the mixture of HF and HClO4 acids, and the content of forms available for plants, after the extraction with DTPA solution, using ASA method. The investigated soils are characterized as loamy sands or sands (PTG 2008). These soils have the content of C-organic in the range of 10.3.24.2 g·kg-1 in the surface horizons and 8.3.20.3 g·kg-1 in the subsurface horizons. The pH values allow to classify these soils as alkaline. In all of the investigated soils calcium carbonate occurs. The values of total content of nickel were in the range of 1.47.2.82 mg·kg-1 in surface horizons and 1.80.2.45 mg·kg-1 in subsurface horizons, which allows to classify these soils as soil with natural nickel content. The content of Ni-DTPA were in the range of 0.06.0.26 mg·kg.1. The sequential analysis of the obtained results indicates on significant statistically positive correlation between the total content of Ni and C-organic, which has the value of 0.648143 and between the content of Ni-DTPA and the content of fraction with Ø<0.002 mm, with the value of 0.581113 on p=0.05.
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Gersztyn, Leszek, Anna Karczewska e Bernard Gałka. "Influence of pH on the solubility of arsenic in heavily contaminated soils / Wpływ pH na rozpuszczalność arsenu w glebach silnie zanieczyszczonych". Ochrona Srodowiska i Zasobów Naturalnych 24, n. 3 (1 settembre 2013): 7–11. http://dx.doi.org/10.2478/oszn-2013-0031.
Testo completoAbstract (sommario):
Abstract The aim of this study was to determine the impact of pH on arsenic solubility in soils heavily contaminated by the former arsenic industry. For the purpose of the study, three soil samples were collected from the area affected by ore processing in Złoty Stok. Soils differed in initial pH, calcium carbonate content, organic matter content and total arsenic concentration. The amounts of arsenic released from soils at various pH were measured using extraction tests, where soil samples were shaken with various doses of HCl and NaOH in the presence of 0.01 mol • dm−3 CaCl2 as the background solution. Arsenic solubility in soils was considerably low at neutral or slightly acidic pH and increased considerably in both strongly acidic and alkaline conditions. The importance of these effects for environmental risk was discussed.
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Ahmed, Niaz, Umama Habib, Uzma Younis, Inam Irshad, Subhan Danish, Ashfaq Ahmad Rahi e Tariq Muhammad Munir. "Growth, chlorophyll content and productivity responses of maize to magnesium sulphate application in calcareous soil". Open Agriculture 5, n. 1 (9 dicembre 2020): 792–800. http://dx.doi.org/10.1515/opag-2020-0023.
Testo completoAbstract (sommario):
AbstractMagnesium (Mg) is an essential plant macronutrient responsible for modulating many physiological or biochemical processes such as photosynthetic activity, amino acid synthesis and nucleotide metabolism. Agricultural soils with a more-than-adequate availability of calcium (Ca) have inherent Mg deficiency, potentially resulting in overall reduced soil productivity and crop yield potential. We conducted a field experiment to investigate the optimum soil application of Mg to increase crop growth and productivity under calcareous soil conditions. In addition to recommended soil application of mineral fertilizers, we applied the following four levels of Mg to the soil in the form of anhydrous MgSO4: control, 4 kg Mg ha−1 (Mg4), 8 kg Mg ha−1 (Mg8) and 16 kg Mg ha−1 (Mg16). Results showed that Mg16 application enhanced the plant height (21%), number of grains (18%), 1,000 grains weight (20%), grain yield (20%) and biological yield (9%) over control (p ≤ 0.05). Chlorophyll a, chlorophyll b and total chlorophyll were generally higher at the Mg8 and Mg16 levels than at the control level. Contrasting to increases in growth traits, the concentration of K significantly decreased in grains, leaves and shoots of maize along the soil’s Mg gradient (p ≤ 0.05). We suggest that Mg16 overcomes the deficiency of soil Mg and can increase the crop yield traits in calcareous soils. More investigations of the effect of soil Mg on various crops grown in calcareous soils may add to our knowledge related to the stressing impact of soil Mg on plant K concentration.
41
Pochernyaeva, E. P., V. O. Okata, O. V. Kotovych e V. M. Yakovenko. "Influence of irrigated mineralized waters on properties of ordinary chernozem in the conditions of Prysamaria Dniprovske". Ecology and Noospherology 31, n. 2 (25 ottobre 2020): 93–98. http://dx.doi.org/10.15421/032015.
Testo completoAbstract (sommario):
Irrigation of lands in arid climates helps to solve the problem of water deficit of soils in order to increase their fertility. However, under the influence of mineralized waters used for irrigation, there is a degradation of chemical, physico-chemical, water-physical and physical properties of soils. Soil monitoring is one of the effective mechanisms that allowsassessing the current state of soils and predicting the negative consequences of economic activity in the future. The area where the research was conducted is in the zone of insufficient moisture where there is an annual deficit of water balance of soils. Irrigation in the studied areas began in the mid-70s of the last century and lasted until 1992. The waters of the Samara River were used for this purpose. The total mineralization of water during the growing season reaches 3515 mg/dm3. It is possible to estimate the degree of transformation of soils that have been under the influence of irrigation waters for a long time in relation to the indicators of virgin soils. The zonal soils of the research area are CalcicChernozems. The analysis of macromorphological indicators showed that irrigation soils differ from the reference ones by the thickness of the organogenic horizon, density and structure. The results of the analysis of the aqueous extract of the reference soils show the absence of salinization with water-soluble salts. Their content varies in the range from 0.051 to 0.078 %. A maximum of one salt is observed in the soil profile, namely in the transitional horizon at a depth of 45–63 cm. Below this depth, the content of water-soluble salts progressively decreases. The total content and distribution of water-soluble salts in the soil profile of irrigated soils has some differences from the reference soils. In the upper part of the humus horizon, the total amount of water-soluble salts is smaller, which can be attributed to the effects of machining and better aeration, as well as the intensive removal of their vegetation. Below these horizons, the amount of water-soluble salts progressively increases and reaches a maximum in the soil-forming rock. The nature of the distribution in the soil profile and the total amount of salts isnot typical for Calcic Chernozems and ismore similar to those of Gleyic Calcic Chernozems. The maximum amount of water-soluble salts is concentrated in the parent rock. Their percentage indicates the absence of salinity in both studied soils. But guided by the method of calculating the content of toxic water-soluble salts in the soil, in the reference soils, this figure reaches 0.21 t/ha in a meter layer of soil, and in irrigation 0.42 t/ha. The results of studies of physicochemical parameters show that a higher content of metabolic calcium is characteristic of the reference soils, and its distribution in the soils along the profile of both options is relatively similar. In contrast, the distribution of exchangeable magnesium in the soil profile varies greatly, especially in the reference soils. In irrigated soils, the ratio of exchangeable calcium to magnesium is more stable and varies in the range from 4.2 to 7.9, which may be the result of prolonged irrigation. According to the obtained physicochemical parameters, irrigation soils have weak salinity in the lower part of the transition horizon. This indicator, together with the ratio of exchangeable calcium to magnesium, indicates eluvial-illuvial processes that for some time contributed to the redistribution in the soil profile of both water-soluble salts and exchangeable cations. Evaluation of the degree of salinity of soils showed the absence of salinization in the reference soils, as well as in the upper part of the humus horizons of irrigated soils. Given the buffering of irrigated soils, weak salinity is present only in the upper part of the transition horizon.
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Sadykhova, M. "Physical and Chemical Indicators of Meadow Brown Soils". Bulletin of Science and Practice 7, n. 7 (15 luglio 2021): 39–42. http://dx.doi.org/10.33619/2414-2948/68/05.
Testo completoAbstract (sommario):
The research has established that the carbonate content of meadow brown soils in the upper and lower horizons varies between 1–9–11%. Where in, the calcium content reaches 85–90%. The content of physical day and silt fraction is 42–75% and 24–36% respectively and is concentrated mainly in the middle part of the profile.
43
Jiménez-Ballesta, Raimundo, Sandra Bravo, José Angel Amorós, Caridad Pérez-de los Reyes, Jesús García-Pradas e Francisco J. García-Navarro. "Understanding the Quality of Local Vineyard Soils in Distinct Viticultural Areas: A Case Study in Alcubillas (La Mancha, Central Spain)". Agriculture 10, n. 3 (6 marzo 2020): 66. http://dx.doi.org/10.3390/agriculture10030066.
Testo completoAbstract (sommario):
The essential features of the soils of a pilot zone in La Mancha (Central Spain), namely the Alcubillas municipability, have been characterized. The soil properties that may contribute to a better understanding of the impact of soil on grape production have also, been evaluated. For this, several soil profiles have been described and analyzed and the profiles have been mapped. The soils are mainly Entisols, Inceptisols and Alfisols, with their evolution controlled by the action of a xerophytic Mediterranean climate. Most of these soils have a loamy clay texture, with medium clay contents and sufficient nutrient contents (despite the low content in organic matter 1.39% and 1.04%, and the high concentrations of calcium carbonate 23.7% and 26.9% in the surface and subsurface horizons, respectively). Drainage problems were not observed and it can therefore be stated that the Alcubillas vineyards are based on a ‘terroir’ term for the production of high quality grapes. In general, the soils are not subjected to treatments to control possible diseases or pests and we have therefore postulated that the soils represent the ideal scenario to establish a distinctive zone and for the increasingly valued ecological and natural viticulture.
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Jia, Yanlong, Tangfu Xiao, Jialong Sun, Zengping Ning, Enzong Xiao, Xiaolong Lan e Yuxiao Chen. "Calcium Enhances Thallium Uptake in Green Cabbage (Brassica oleracea var. capitata L.)". International Journal of Environmental Research and Public Health 20, n. 1 (20 dicembre 2022): 4. http://dx.doi.org/10.3390/ijerph20010004.
Testo completoAbstract (sommario):
Thallium (Tl) is a nonessential and toxic trace metal that is detrimental to plants, but it can be highly up-taken in green cabbage (Brassica oleracea L. var. capitata L.). It has been proven that there is a significant positive correlation between Tl and Calcium (Ca) contents in plants. However, whether Ca presents a similar role for alleviating Tl toxicity in plants remains unclear, and little is known in terms of evidence for both Ca-enhanced uptake of Tl from soils to green cabbage and associated geochemical processes. In this study, we investigated the influence of Ca in soils on Tl uptake in green cabbage and the associated geochemical process. The pot experiments were conducted in 12 mg/kg Tl(I) and 8 mg/kg Tl(III) treatments with various Ca dosages. The results showed that Ca in soils could significantly enhance Tl uptake in green cabbage, increasing 210% in content over the control group. The soluble concentrations of Tl were largely increased by 210% and 150%, respectively, in 3.0 g/kg Ca treatment, compared with the corresponding treatment without Ca addition. This was attributed to the geochemical process in which the enhanced soluble Ca probably replaces Tl held on the soil particles, releasing more soluble Tl into the soil solution. More interestingly, the bioconcentration factor of the leaves and whole plant for the 2.0, 2.5, 3.0 g/kg Ca dosage group were greatly higher than for the non-Ca treatment, which could reach 207%, implying the addition of Ca can improve the ability of green cabbage to transfer Tl from the stems to the leaves. Furthermore, the pH values dropped with the increasing Ca concentration treatment, and the lower pH in soils also increased Tl mobilization, which resulted in Tl accumulation in green cabbage. Therefore, this work not only informs the improvement of agricultural safety management practices for the farming of crops in Tl-polluted and high-Ca-content areas, but also provides technical support for the exploitation of Ca-assisted phytoextraction technology.
45
Kowalska, Joanna, Bartłomiej Kajdas e Tomasz Zaleski. "Variability of morphological, physical and chemical properties of soils derived from carbonate-rich parent material in the Pieniny Mountains (south Poland)". Soil Science Annual 68, n. 1 (28 marzo 2017): 27–38. http://dx.doi.org/10.1515/ssa-2017-0004.
Testo completoAbstract (sommario):
Abstract Carbonate-rich soils are characterized by great diversity in content of carbonate and non-carbonate mineral substances in soil substrate which largely influences soil properties. The study presents the analysis results of four soil profiles located at the area of Pieniny National Park. The aim of this study was to characterize and classify the soils developed from the mixture of carbonate and carbonate-rich rock material, formerly classified as pararendzinas. It was achieved by determination of morphological, physical, and chemical properties, as well as mineralogical composition of selected carbonate-rich soils occurring in the Polish part of the Pieniny Mts. Soils were classified as typical chernozemic rendzina (P1), typical eutrophic brown soils (P2, P4), as well as typical pararendzina (P3) according to Polish Soil Classification (2011). The parent material of studied soils P1, P2 and P4 were slope covers, with a dominant share of sandstone and minor share of limestone, whereas soil P3 was formed from variegated shale cut with multiple calcite veins. Soils were characterized by stable aggregate structure: crumby, angular blocky and subangular blocky. They were medium or strong skeletal, mostly with loam texture with great share of silt fraction. CaCO3 content in genetic horizons ranged from 0.0 to 703.0 g·kg-1. The reaction of studied soils was from weakly acidic to alkaline. Analysed soils were characterized by very high base saturation. Among determined exchangeable cations, Ca2+ ions had the biggest share in all analysed profile. High base saturation, as well as high content of calcium carbonate was accompanied by content of organic matter and percentage content of clay fraction. Taking into consideration determined chemical and physical properties, it can be found that investigated soils were influenced by not only the in-situ weathering material but also by rock material which have been transported and deposited as a result of slope processes. Furthermore, the lack or lower content of CaCO3 in surface and middle part of analysed soil profiles was most likely a result of the impoverishment of rock material during the transport on the slope.
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Brennan, R. F., M. D. A. Bolland e R. W. Bell. "Increased risk of zinc deficiency in wheat on soils limed to correct soil acidity". Soil Research 43, n. 5 (2005): 647. http://dx.doi.org/10.1071/sr04162.
Testo completoAbstract (sommario):
Addition of lime to ameliorate soil acidity has been observed to induce zinc (Zn) deficiency for wheat in sandy soils of south-western Australia, reducing grain yields. The implications of widespread use of lime to treat acid soils for the residual value of Zn in these soils are not known. In a glasshouse experiment, using a Zn-deficient sand from south-western Australia, 3 levels of finely powdered calcium carbonate were added and incubated in moist soil for 6 weeks at 22°C to produce three different pH values (1 : 5 soil : 0.01 m CaCl2): 4.9 (original soil not treated with calcium carbonate), 5.8, and 7.4. Five amounts of Zn, as solutions of Zn sulfate, were then incubated in moist soil for 0, 30, 60, 120, and 180 days before sowing spring wheat (Triticum aestivum L.). The residual value of the applied Zn was determined using yield of dried shoots, Zn content in dried shoots, and soil test Zn (DTPA extraction). This was done by calculating the effectiveness of the incubated Zn for all 3 soils relative to the effectiveness of Zn applied just before sowing wheat (0 day incubation, freshly applied Zn) for the soil not treated with calcium carbonate. As measured using yield of dried shoots, Zn content of dried shoots, or soil test Zn, the residual value of the incubated Zn decreased with increasing soil pH and with increasing period of incubation of Zn with moist soil before sowing wheat. The critical Zn concentration, associated with 90% of the total yield of dried wheat shoots, was (mg Zn/kg) 13 in the youngest mature growth (apex and youngest emerged leaf), and 20 for rest of dried shoots. These values were similar to current critical values for unlimed soils. The relationship between yield of dried shoots and DTPA soil test Zn was similar for unlimed and limed soils, so similar critical soil test Zn was applicable on the sandy soil regardless of soil pH. Critical DTPA soil test Zn, the soil test Zn that was related to 90% of the maximum yield of dried shoots, was 0.14 mg Zn/mg soil. To combat the increased risk of Zn deficiency on soils limed to ameliorate soil acidity, fertiliser Zn needs to be re-applied to the soil when soil and plant tests indicate a high likelihood of deficiency.
47
Krzyżaniak, M., e J. Lemanowicz. "Enzymatic activity of the Kuyavia Mollic Gleysols (Poland) against their chemical properties ". Plant, Soil and Environment 59, No. 8 (31 luglio 2013): 359–65. http://dx.doi.org/10.17221/211/2013-pse.
Testo completoAbstract (sommario):
The research results have shown that the enzyme pH index (0.49–0.83) confirmed the neutral or alkaline nature of the soils. Neither the changes in the content of available phosphorus nor in the activity of dehydrogenases, catalase, alkaline and acid phosphatase in soil were due to the factors triggering soil salinity; they were a result of the naturally high content of carbon of organic compounds, which was statistically verified with the analysis of correlation between the parameters. There were recorded highly significant values of the coefficients of correlation between the content of available phosphorus in soil and the activity of alkaline (r = 0.96; P < 0.05) and acid phosphatase (r = 0.91; P < 0.05) as well as dehydrogenase (r = 0.90; P < 0.05). To sum up, one can state that Mollic Gleysols in Inowrocław are the soils undergoing seasonal salinity; however, a high content of ions responsible for salinity is balanced with a high content of organic carbon, humus, phosphorus and calcium directly affecting the fertility of the soils analyzed. The activity of the enzymes depended on the natural content of carbon of organic compounds and not on the factors affecting the soil salinity, which points to the potential of such tests for soil environment monitoring.
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Bernini, Thiago Andrade, Marcos Gervasio Pereira, Lúcia Helena Cunha dos Anjos, Daniel Vidal Perez, Ademir Fontana, Sebastião Barreiros Calderano e Paulo Guilherme Salvador Wadt. "Quantification of aluminium in soil of the Solimões Formation, Acre State, Brazil". Revista Brasileira de Ciência do Solo 37, n. 6 (dicembre 2013): 1587–98. http://dx.doi.org/10.1590/s0100-06832013000600015.
Testo completoAbstract (sommario):
The variety of soils in the State of Acre is wide and their chemical profiles are still not fully understood. The nature of the material of origin of these soils is indicated by the high aluminium (Al) content, commonly associated with high calcium (Ca) and magnesium (Mg) contents. The study objective was to use different methods to quantify Al in soils from toposequences formed from material of a sedimentary nature originating from the Solimões Formation, in Acre, Brazil. Trenches were opened at three distinct points in the landscape: shoulder, backslope and footslope positions. Soil samples were collected for physical, chemical, mineralogical analyses. The Al content was quantified using different methods. High Al contents were found in most of these horizons, associated with high Ca and Mg levels, representing the predominant cations in the sum of exchangeable bases. The mineralogy indicates that the soils are still in a low weathering phase, with the presence of significant quantities of 2:1 minerals. Similar Al contents were determined by the methods of NaOH titration, xylenol orange spectrometry and inductively coupled plasma optical emission spectrometry. However, no consistent data were obtained by the pyrocatechol violet method. Extraction with KCl overestimated the exchangeable Al content due to its ability to extract the non-exchangeable Al present in the smectite interlayers. It was observed that high Al contents are related to the instability of the hydroxyl-Al smectite interlayers.
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Wu, Dazhi, Zilong Zhang, Keyu Chen e Linling Xia. "Experimental Investigation and Mechanism of Fly Ash/Slag-Based Geopolymer-Stabilized Soft Soil". Applied Sciences 12, n. 15 (25 luglio 2022): 7438. http://dx.doi.org/10.3390/app12157438.
Testo completoAbstract (sommario):
In response to the high carbon emissions and energy consumption of traditional cement curing agents, in this paper, we propose a fly ash/slag-based geopolymer as an alternative to cement for stabilizing soft soils. In this study, the effects of the activator modulus, activator, and slag content on the geopolymer-stabilized clay were investigated by unconfined compressive strength (UCS) tests on Hangzhou soft soils, and the water stability and resistance to wet–dry cycles of the geopolymer-stabilized soils were studied. The changes in the microstructure and mineral phases were investigated using X-ray diffraction and scanning electron microscopy, respectively, and the inner evolution of the properties of the stabilized soft soil under different conditions was clarified. The test results revealed that the UCS of the geopolymer-stabilized soft soils increased and then decreased as the content and modulus of the alkali activator increased. The optimum mix proportion of geopolymer-stabilized soil required a modulus of the alkali activator of 0.6, a content of the alkali activator of 6%, and a slag-to-fly ash ratio of 1:1. Its 28-day UCS of the test specimens reached 2 MPa. When the content of the geopolymer was 25%, the water stability coefficient reached 87.53%, and the strength was still 1.6 MPa after eight wet–dry cycles. Based on the microscopic analysis, the cementing substances in the geopolymer-stabilized clay were calcium silicate hydrate (C-S-H) and sodium aluminosilicate hydrate (N-A-S-H), which made the soil’s structure denser through bonding and filling effects.
50
Zhu, Wanyi, Mengnan Yuan, Fanmin He, Yang Zhao, Zhiyang Xiao, Qian Wang, Fanyou Meng e Qiang Tang. "Effects of Hydroxypropyl Methylcellulose (HPMC) on the Reinforcement of Sand by Microbial-Induced Calcium Carbonate Precipitation (MICP)". Applied Sciences 12, n. 11 (25 maggio 2022): 5360. http://dx.doi.org/10.3390/app12115360.
Testo completoAbstract (sommario):
Microbial-induced calcium carbonate precipitation (MICP) is a new technology used for reinforcing soils through microbial mineralization. However, the existing MICP treatment technology is more suiTable for deeper soils due to its high permeability. In this study, HPMC, a cohesive material combined with Sporosarcina pasteurii-induced calcium carbonate precipitation was used to improve the surface layer of the soil. It was also tested in different contents of bacterial solutions and cementation solutions and with a different number of MICP treatments, and was analyzed and discussed by measuring the surface layer strength, calcium carbonate content generated in the crust, rainfall erosion resistance, wind erosion resistance, and ammonia retention rate of the specimens. The microstructure of the samples was investigated by XRD and SEM. It was shown that the addition of HPMC and increasing the number of MICP treatments were effective in the increase in the calcium carbonate content in the surface crust, but had no effect on the total amount of induced calcium carbonate. The combination of HPMC addition and MICP technology can effectively reduce rainwater scour loss and wind erosion loss, and increase its rainfall erosion resistance and wind erosion resistance. Rainfall losses were reduced by up to 30% in specimens treated with HPMC for MICP technology. When the wind speed was 12 m/s, the maximum mass loss rate of the specimens treated with HPMC for MICP was only 0.828%. The addition of HPMC can effectively improve the ammonia absorption rate and reduce the release of ammonia in the process of MICP technology, which is of great significance for environmental protection. The microstructure showed that the addition of HPMC and the increase in the number of treatments using MICP technology can make the surface structure of the specimens more compact, and the calcium carbonate can more effectively fill the pores and cement the soil particles, while the addition of HPMC may not change the calcium carbonate crystal type.