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1
Jęruszczak, Maria. "Plant communities of stubble-fielde in the Lublin region. P.llI. Plant communities of rich and humid sites." Acta Agrobotanica 43, no. 1-2 (2013): 155–72. http://dx.doi.org/10.5586/aa.1990.013.
Анотація:
Two plant communities have been distinguished on the fertile and humid solis in the Lublin region. I. <i>Oxalido-Chenopodietum polyspermi</i> Siss. 1942 (especially on the alluvial soils developed from loams, clays and silts); 2. <i>Rorippa sylvestris-Oxalis stricta</i> (on the loess, silts of water origin and alluvial soils developed from loamy sands). Each of the two types of communities was divided into two variants differing in floristic composition, which reflected the diversity of trophical, hydrological and pH conditions these soils.
2
Galitskova, Yulia M. "Contamination of Soils and Sub-Soils at Construction Sites." IOP Conference Series: Materials Science and Engineering 661 (November 21, 2019): 012144. http://dx.doi.org/10.1088/1757-899x/661/1/012144.
3
Radhi Jubier, Amal, and Mustafa Thabit Ail. "Agricultural exploitation and physiographic location in the availability of nutrients to the soil of Diyala Governorate." Sumer 4 8, CSS 4 (October 15, 2023): 1–9. http://dx.doi.org/10.21931/rb/css/2023.08.04.22.
Анотація:
The study area was chosen to include three physiographic sites on the Diyala River, as it is located in the village of Umm Al-Azam between longitudes 33.71785 east and latitudes 44.6185 north. There are four pedons in each A physiographic unit, two of which are in cultivated sites and the other two are in unexploited agricultural sites, so the total of the studied pedons is twelve. The results of laboratory analysis showed that the lowest content of available nitrogen for the cultivated sites was in the soils of river levees and the highest content in the soils of the river basins, while in the abandoned soil sites, it was the lowest content in the soils of the river basins and the highest content in the soils of depressions, and that the variance of the available nitrogen content in the soils of the cultivated pedons sites was moderate. The results indicated that the available phosphorous content in the sites of cultivated pedons soils ranged between 17.25 – 40.24 mg kg-1 as it was the lowest content in river levee and the highest in the depressions soils, while the available phosphorous content in the soils of the abandoned pedons sites ranged between 19.19 - 43.00 mg kg-1 as it was the lowest content in river basins and the highest content in depressions soils, while the variance of phosphorus in the cultivated soils pedons was of slight variation available. The available potassium content in the soils of the planted pedons sites ranged between 175.60 - 255.17 mg kg-1 , as it was the lowest content in the river levee and the highest in the soils of the river basins. The available potassium content in the soils of the abandoned pedons sites ranged between 170.64 - 257.45 mg kg-1 , where the lowest content of the available potassium was in the river levee soils, and the highest was in the depressions soils. Also, the variance of the available potassium in the pedons' soils was very little. As for the effect of the interaction between agricultural exploitation and physiographic sites and horizons in the characteristics of the study area, the results of the statistical analysis indicated that all study indicators represented by sites, type of use, horizons and their interactions did not have a significant effect of increasing nitrogen in the soil of the study area, as well as phosphorous and potassium. Keywords: N, P, K, nutrients, physiographic location, agricultural exploitation.
4
Abed, Abdulkareem H. "Estimation of Dispersion Phenomena for Selected Sites in Babylon Governorate." Journal of University of Babylon for Engineering Sciences 26, no. 7 (July 3, 2018): 95–111. http://dx.doi.org/10.29196/jubes.v26i7.1491.
Анотація:
This investigation is conducted to estimate the dispersion phenomena for selected sites in Babylon governorate (ALkheder – Almossiab, ALsadda, ALbunafaa, ALhashmia,).
The main aim of this investigation is to study dispersion phenomena, and identification and classification of soils to (high, intermediate, and non-dispersion) depending on special test methods in dispersion phenomena. The experimental tests that were done; indexes, physical, and chemical tests to natural soils and special tests were done to the identification and classification of dispersion soils.
The results of crumb test showed weak dispersion (Grade 2) for AL sadda soil, but the soils of ((ALkhezer – Almossaab, AL.bunafaa, AL.hashmia) showed intermediate dispersion (Grade 3).
The results of the double hydrometer test showed that ALkheder – Al.mossaab, and ALbunafaa were of intermediate dispersion soils, and for AL.hashmia, and AL sadda soils were non – dispersive.
The results of slacking test indicated that (ALkheder - Almossaab, ALbunafeej) were dispersive soils and (AL.hashmia, ALsadda soils) were non– dispersive.
While the results of soluble salts in pore water test indicated that all soils were non–dispersive but with different ratios according to its position in zone B of the classification chart.
5
Lang, Friederike, and Martin Kaupenjohann. "Molybdenum at German Norway spruce sites: contents and mobility." Canadian Journal of Forest Research 30, no. 7 (July 1, 2000): 1034–40. http://dx.doi.org/10.1139/x00-022.
Анотація:
Molybdenum plays an important role in the nitrogen turnover of ecosystems. However, very little is known about Mo availability in forest soils. We measured the oxalate-extractable Mo concentrations of acid forest soils, the Mo, nitrate, phosphate, and sulfate fluxes from the organic forest floor into the mineral soil using resin tubes and the Mo concentrations of the tree needles at 28 different Norway spruce (Picea abies (L.) Karst.) sites in southern Germany. The supply of oxalate-extractable Mo varied from 51 to 3400 g·ha-1, with the lowest values occurring in sandstone-derived soils (370 ± 212 g·ha-1; mean ± SD). Molybdenum concentrations of current-year needles were in the range of 5 to 48 ng·g-1. The Mo needle concentrations and oxalate-extractable Mo of soils did not correlate. However, Mo fluxes (6-60 g·ha-1·a-1) from the organic forest floor into the mineral soils were correlated to needle concentrations and to the NO3 fluxes. We conclude that Mo turnover within forest ecosystems is governed by Mo plant availability of mineral soils as well as by plant Mo uptake. In addition, Mo cycling strongly affects Mo distribution within soil profiles and Mo fluxes out of the organic layer.
6
Jones, David T., Homathevi Rahman, David E. Bignell, and Anggoro H. Prasetyo. "Forests on ultramafic-derived soils in Borneo have very depauperate termite assemblages." Journal of Tropical Ecology 26, no. 1 (December 8, 2009): 103–14. http://dx.doi.org/10.1017/s0266467409990356.
Анотація:
Abstract:Previous studies in Sundaland (Borneo, Sumatra, Java and Peninsular Malaysia) have shown that termite assemblages in natural forests have a characteristic structure. These typical forest assemblages contain many soil-feeding species. However, this study investigated four natural forest sites in Borneo with depauperate termite assemblages, and compared their soils with soils from four other sites that have typical termite assemblages. In contrast to the typical assemblages, the four depauperate assemblages all have low species density (<35%), low relative abundance (<30%), a virtual absence of soil-feeders, significantly fewer wood-feeders, and a near-absence of species of Rhinotermitidae, Amitermes-group, Termes-group, Pericapritermes-group and Oriensubulitermes-group. The depauperate sites are on ultramafic-derived soils and have significantly higher concentrations of calcium, magnesium, nickel, chromium, cobalt, copper and zinc compared with the non-ultramafic soils at sites with typical assemblages. In addition, soil pH at the depauperate sites is significantly higher (>pH 5.4) compared with soils at the typical sites (which are all below pH 4.7). Possible mechanisms to explain the depauperate termite assemblages on ultramafic soils include metal toxicity, high pH disrupting gut physiology, and microbial interactions with metals.
7
ZENG, Yunmin, Li'ao WANG, Tengtun XU, Xue SONG, and Yanze YANG. "Performance of an intermediate soil cover for landfill sites." Earth and Environmental Science Transactions of the Royal Society of Edinburgh 109, no. 3-4 (September 2018): 429–36. http://dx.doi.org/10.1017/s175569101800052x.
Анотація:
ABSTRACTThis study aimed to improve the performance of an intermediate covering of soils in landfill sites by using agents such as calcined lime, sawdust and polyacrylamide (PAM). Compressive strength, permeability and water-holding capacity of modified soils were measured, and the effects of regulating pH and pollutant removal in leachate were also investigated in a leaching experiment. The results indicate that three modifying agents could improve the compressive strength of an intermediate soil cover. The permeability of lime-treated soil increased as the amount of lime increased, while that of sawdust- and PAM-modified soil declined. Results from a leaching experiment show that lime- and sawdust-modified soils could improve leachate quality. The pH value of leachate from 5% lime-modified soils was 7.78, which is suitable for the metabolism of anaerobic microorganisms. The removal efficiencies of chemical oxygen demand, total organic carbon, total nitrogen and volatile fatty acids in leachate permeating lime- and sawdust-modified intermediate cover was improved so that the pollution load of leachate was reduced. The water-holding capacities for 20% sawdust and 0.5% PAM-modified soils were 65.19% and 43.52%, respectively, which helps to maintain the optimum water content of landfill. The water-holding capacity of PAM-modified samples declined in alkaline soil. It is concluded that the combination of 5% sawdust, 5% lime and 90% soil would be optimal for an intermediate covering layer.
8
McANDREW, D. W., and S. S. MALHI. "LONG-TERM EFFECT OF DEEP PLOWING SOLONETZIC SOIL ON CHEMICAL CHARACTERISTICS AND CROP YIELD." Canadian Journal of Soil Science 70, no. 4 (November 1, 1990): 565–70. http://dx.doi.org/10.4141/cjss90-059.
Анотація:
Deep plowing (DP) has been investigated as a possible ameliorative procedure for Solonetzic soils, but the long-term effects of DP on soil properties are not known. Soil sampling to determine the long-lasting effects of DP on some soil chemical properties and crop yields was conducted at four sites with Solonetzic soils in east-central Alberta. The soils had been deep plowed 11–29 yr prior to sampling. Compared to adjacent unplowed (check) treatments, DP resulted in significant improvements in soil chemical properties at most of the sites. The sodium adsorption ratio (SAR) of the AB horizon (12- or 15- to 30-cm depth) was lower after DP at all four sites. Extractable and soluble Ca increased in the Ap horizon (0–12 cm) of DP soils, whereas extractable Na decreased in the Ap or AB horizons at three sites. The pH of the Ap horizon increased from acidic to neutral at three sites, while EC of the Ap horizon decreased at two sites. Crop yield increased due to DP at the three sites where yields were measured. The results indicate a long-term amelioration of Solonetzic soils by DP. Key words: Amelioration, deep plowing, deep tillage, sodic soil
9
Al-Kawam, Fatima Q., and Raid A. Mahmood. "The Effect of Geotechnical Factors in Road of Basrah, Southern Iraq." Iraqi Geological Journal 55, no. 1C (March 31, 2022): 157–69. http://dx.doi.org/10.46717/igj.55.1c.12ms-2022-03-31.
Анотація:
Most Basrah roads are conducted to a major failure in their layers and bases, which appears in the form of cracking, crushing, landing, as well as massive holes. The influence of geotechnical factors on the performance of Basrah roads has been studied. Sixteen sites were selected for sampling, which are Al-Medaina, West Qurna, Al-Hartha, Al-Dir, Shatt Al-Arab, Al-Tuwaisa, Hayy-Al-Hussein, Al-Shuaiba, Al-Maqal, Al-Gazara, Abu-Al-Khaseeb, Al-Ashar, Umm Qasser, Al-Zubair Petrochemical factory, and Al-Faw. The soil properties were studied up to 3 meters of depth at each location to find out the effect of geotechnical properties on roads. Laboratory tests were carried out on the samples, which included grain size analysis, Atterberg limits, gypsum content, total soluble salts, swelling potential, organic content, and standard penetration test. The results presented that the percentage of gypsum exceeded the allowable limit in the standard specifications at the sites (S7, S8, S13, S14, S16). Also, the percentage of total soluble salts exceeded the allowable limit in the standard specifications at the sites (S5, S8, S16). The results showed that the soils in S1, S2, S3, S4, S7, S11 have medium swelling potential, which requires treating before building roads on them. The results also showed that the percentage of organic materials exceeded the permissible limit in the standards specifications at the sites S1, S2, S3, S4, S5, S9, S10, S11, S12, S15. The results also showed that the cohesive soils in the first meter of the sites (S2, S5, S11), the second meter of the sites (S2, S7, S12) and the third meter of the sites (S5, S9, S10, S11, S12) are medium stiff soils, which requires treating before building roads on them. While the non-cohesive soils at the two sites (S8, S13) are medium dense soils, in two sites (S14, S16) are loose sandy soils in the first meter, while the second meter in sites (S8, S13, S14, S16) are medium dense soils, and the third meter at the site (S14) is medium dense soils.
10
Mori Alvez, Cristina, Carlos Perdomo Varela, Pablo González Barrios, Andrea Bentos Guimaraes, and Amabelia del Pino Machado. "Lupine Cultivation Affects Soil’s P Availability and Nutrient Uptake in Four Contrasting Soils." Agronomy 14, no. 2 (February 18, 2024): 389. http://dx.doi.org/10.3390/agronomy14020389.
Анотація:
A substantial amount of phosphorus (P) in the soil is not readily available for plant uptake. Certain species may enhance P availability from poorly soluble P forms. This study focused on improving our comprehension of the effect of two lupine species (L. albus and L. angustifolius) on soil’s P mobilization and its link with soil acidity variations, comparing the response of the lupine species in terms of plant traits (i.e., aboveground biomass and nutrient uptake) with that of oats (Avena strigosa L.) in four contrasting soils (i.e., available P in soil, soil acidity, soil fertility, and texture). The phosphorus solubilization capacity was assessed on variations of P availability (PBray1) at four points in time, comparing soils with lupine to oat-containing soils and their baseline values. Compared to soils containing oats, at harvest, lupine soils had significantly increased PBray1 concentrations; the maximum average increment was around 5.3 mg kg−1, with L. albus in Sites 1 and 2, which presented higher organic matter (OM) contents than the other two sites. Lupine-induced soil acidification did not fully explain that P increase. Oats exhibited the highest increase in shoot dry weight in response to soil’s P availability, while lupine was the least affected. Nevertheless, L. albus showed similar or higher nutrient uptake than oats across all soils. The manganese (Mn) concentration was high in both lupine species’ shoot biomass; however, within each lupine species, across all soil types tested, these legumes had different Mn accumulation levels depending on the soil acidity. Lupinus albus had a higher ability to mobilize non-labile P in the light-textured soil with a high OM content, achieving comparable and higher plant P status than oats and providing N through biological N fixation (BNF), positioning it as a suitable crop for diversifying Uruguay’s agricultural crop rotation systems.
11
Vilkova, V. V., K. S. Кazeev, V. V. Shabunina, and S. I. Kolesnikov. "ENZYMATIC ACTIVITY OF POST-PYROGENIC SOILS OFTHE UTRISH RESERVE." Bulletin of the State Nikitsky Botanical Gardens 1, no. 138 (May 14, 2021): 71–77. http://dx.doi.org/10.36305/0513-1634-2021-138-71-77.
Анотація:
Southem Federal University, Academy ofBiology and Biotechnology, Rostov-on-Don, Russia. А study of the enzyme activity of soils in two sites of the Abraus Peninsula in the coastal part of the Utrish reserve was conducted. Sites differ in the period of post-fire recovery. The long-term significant influence of fires on the enzyme activity (catalase, invertase, peroxidase, urease) of brown subtropical soils (Chromic Cambisols) is shown. The activity of various enzymes of soils is reduced compared to the soils of the control sites. The degree of inactivation of enzymes depends on the type of enzyme and the time of post-pyrogenic recovery of ecosystems.
12
Dörr, Nicole, Bruno Glaser, and Steffen Kolb. "Methanotrophic Communities in Brazilian Ferralsols from Naturally Forested, Afforested, and Agricultural Sites." Applied and Environmental Microbiology 76, no. 4 (December 28, 2009): 1307–10. http://dx.doi.org/10.1128/aem.02282-09.
Анотація:
ABSTRACT Conversion of forests to farmland permanently lowers atmospheric methane consumption due to unresolved reasons. Alphaproteobacterial methanotrophs were predominant in forested soils and gammaproteobacterial species were predominant in farmland soils of subtropical ferralsols in Brazil. The capability of atmospheric methane consumption was obliterated in farmland soils, suggesting a shift from oligotrophic to copiotrophic species.
13
Golchin, A., P. Clarke, JM Oades, and JO Skjemstad. "The effects of cultivation on the composition of organic-matter and structural stability of soils." Soil Research 33, no. 6 (1995): 975. http://dx.doi.org/10.1071/sr9950975.
Анотація:
Soil samples were obtained from the surface horizons of five untilled sites and adjacent sites under short- and long-term cultivation. The soil samples were fractionated based on density and organic materials were concentrated in various fractions which enabled comparative chemical composition of the organic materials in cultivated and uncultivated sites by solid-state C-13 CP/MAS NMR spectroscopy. Changes in the nature of organic carbon with cultivation were different in different soils and resulted from variations in the chemistry of carbon inputs to the soils and a greater extent of decomposition of organic materials in cultivated soils. Differences in the chemical composition of organic carbon between cultivated and uncultivated soils resided mostly in organic materials occluded within aggregates, whereas the chemistry of organic matter associated with clay particles showed only small changes. The results indicate a faster decomposition of O-alkyl C in the cultivated soils. Wet aggregate stability, mechanically dispersible clay and modulus of rupture tests were used to assess the effects of cultivation on structural stability of soils. In four of five soils, the virgin sites and sites which had been under long-term pasture had a greater aggregate stability than the cultivated sites. Neither total organic matter nor total O-alkyl C content was closely correlated with aggregate stability, suggesting that only a part of soil carbon or carbohydrate is involved in aggregate stability. The fractions of carbon and O-alkyl C present in the form of particulate organic matter occluded within aggregates were better correlated with aggregate stability (r = 0.86** and 0.88**, respectively). Cultivation was not the dominant factor influencing water-dispersible clay across the range of soil types used in this study. The amount of dispersible clay was a function of total clay content and the percentage of clay dispersed was controlled by factors such as clay mineralogy, CaCO3 and organic matter content of soils. The tendency of different soils for hard-setting and crusting, as a result of structural collapse, was reflected in the modulus of rupture (MOR). The cultivated sites had significantly higher MOR than their non-tilled counterparts. The soils studied had different MOR due to differences in their physical and chemical properties.
14
Blair, B. L., R. C. Magarey, J. I. Bull, and E. J. Johnson. "Biological studies of soils in paired old and new land sites growing sugarcane." Australian Journal of Experimental Agriculture 37, no. 4 (1997): 451. http://dx.doi.org/10.1071/ea96137.
Анотація:
Summary. The growth of sugarcane in soils from land monocultured with sugarcane, and from land which had either never been cropped with sugarcane, or just recently cropped, was compared under glasshouse conditions. In general, cane growth in new land soils was greater than in monocultured soil (shoot growth 7.4%, root growth 21.4%). Responses to soil pasteurisation were investigated in some soils and were greater in monocultured soils suggesting that root growth constraints were larger in the monocultured soil (210% response in monocultured soils v. 64% in new land soils). Assays for sugarcane root pathogens suggested that Pachymetra chaunorhiza was a major contributor to the old/new land growth responses, but it is unlikely that Pythium spp. were factors in the growth differences. Monitoring of other groups of organisms in soil from one site suggested that sugarcane monoculture may affect populations in the broader biological community.
15
Dachung, Grace, Agida Ernest Ogoda, and David Oriabure Ekhuemelo. "EFFECT OF SAWDUST ON SOIL NUTRIENTS STATUS IN ICHAKOBE, IBILLA IN OJU LOCAL GOVERNMENT AREA OF BENUE STATE." FUDMA JOURNAL OF SCIENCES 6, no. 3 (June 24, 2022): 105–12. http://dx.doi.org/10.33003/fjs-2022-0603-940.
Анотація:
The effect of sawdust on soil nutrients in Oju Local Government Area of Benue State was examined. Three composite soil samples of 500 g were collected each from sawdust dumpsites and adjacent normal sites in Ichakobe Ibilla using a soil auger and stored in a polyethene bag. Soil samples were air-dried and sieved. Physical, chemical and microbial characteristics soil samples were determined according to standard methods. Data were analyzed using analysis of variance (ANOVA) and a follow-up test done using Duncan Multiple Range for any significant difference. The soil colour from normal sites were reddish, reddish-yellow and brownish red while they were ash, brownish and yellowish-brown in soils from sawdust dumpsites. Pseudomonas aurogenous, and Baccilus sp were common to normal and sawdust dumpsites while Entrobacter sp and Escherichia coli were only foun4d in the normal sites and Salmonella sp was seen only in soils from the sawdust dumpsites. Yeast cells and Rhizopus sp were common to soils from normal and sawdust dumpsites while Mucor sp was specific to soils from normal sites. Aspergillus sp was found in soils from sawdust dumpsite. Nitrogen, Phosphorus, Potassium, organic matter, Organic Carbon, Water, and Cation Exchange Capacity tend to be higher in sawdust dumpsites than in the normal site. SO3, Na2O, CaO, Fe2SO4 and MnO were all higher in soils from sawdust dumpsites than soil from soils normal sites. In conclusion, soils from sawdust dumpsites had more nutrient than the normal adjacent soil and as such, it is better for the growth of
16
Golchin, A., and H. Asgari. "Land use effects on soil quality indicators in north-eastern Iran." Soil Research 46, no. 1 (2008): 27. http://dx.doi.org/10.1071/sr07049.
Анотація:
Forest and grassland soils in north-eastern Iran are being degraded and destroyed by inappropriate agricultural activities. This study investigated effects of land-use changes on several indicators of soil quality (SQ) in this area. We found higher organic carbon (OC) and total nitrogen (N) contents in virgin soils (under forests and pastures) than in cultivated soils. Distribution of OC throughout the soil profile was influenced by the type and length of tillage operations performed at different sites. Cultivation reduced OC content of the subsoil (0.50–1.00 m) and contributed to a more uniform distribution of organic matter in the plough layer (0–0.50 m) by mixing upper and lower horizon soils and incorporating of organic inputs to a greater depth. In 4 of 5 sites, tilled soils had lower ECe and SAR values than the virgin soils, but when the water table was near the soil surface, the ECe and SAR values were higher in cultivated sites. This suggests that when the water table is deep, the quality of salt-affected virgin soils may be improved by cultivation and leaching of excess salts to deeper layers. In 4 of 5 sites, the virgin soils had slightly greater clay content than the tilled soils, but these soils also had 41–89% less dispersible clay than their cultivated counterparts. The virgin soils had 2–31-fold greater aggregate stability, 4–33% lower bulk density, 6–31% higher water-holding capacity (at 0.3 bar suction), higher cation exchange capacity (CEC), and higher respiration rate than the cultivated soils. The results of this study indicate that frequent tillage and use of summer fallow deteriorates SQ by decreasing SOC and enhancing soil erosion through decreased structural stability and increased mechanically dispersible clay. The results stress the need for farming practices that preserve OC in soils in order to reduce flooding and erosion risks.
17
Crawford, DM, TG Baker, and J. Maheswaran. "Soil pH changes under Victorian pastures." Soil Research 32, no. 1 (1994): 105. http://dx.doi.org/10.1071/sr9940105.
Анотація:
The severity and extent of surface soil acidification was assessed at 107 pasture sites across Victoria. At each site, soil samples (0.20 cm depth) were taken from the pasture area and an adjacent reference (undisturbed) area for analysis of soil pH (1:5 0.01 m CaCl2 or water). Acidification was evident in the 0.10 cm depth of sites with moderately and slightly acid (pH [water] 5.5-7) reference soils, while alkalinization was evident in the 0.20 cm depth of sites with strongly acid (pH [water] <5.5) reference soils. Causes of pH changes were not clearly evident from the relationships between site factors and changes in soil. It was evident that site factors were confounded since sites that had acidified often supported subterranean clover and had slightly to moderately acid reference soils, while sites which had alkalinized often supported white clover-based pastures under higher rainfall and had more acidic reference soils. An understanding of the causes of acidification in pasture-based agricultural ecosystems will only be gained through more fundamental studies at individual sites.
18
Loehr, R. C., L. A. Rogers, and D. C. Erickson. "Mobility of Residues at Petroleum Industry Hazardous Waste Land Treatment Sites." Water Science and Technology 25, no. 3 (February 1, 1992): 191–96. http://dx.doi.org/10.2166/wst.1992.0092.
Анотація:
This study determined: (a) waste constituents remaining at long-term hazardous waste land treatment (HWLT) sites, and (b) the potential for subsequent degradation and migration of these constituents. Soils from six depths from random test pits at two oil refinery sites and a wood preserving site were evaluated for specific metals and organics. In surface soils, concentrations of organics and metals were greater than in background soils. At depths below 24-30” (60-76 cm) at the HWLT sites, PAH concentrations were below detection limits and the freon-extractable concentrations were at background. Chromium and nickel at depths below 24” (60 cm) appeared greater than background soil concentrations, but not copper, lead, and zinc concentrations. Organics in TCLP extracts of site soils indicated no PAH compounds were extracted from either weathered or non-weathered soils. In most of the site soil samples, metals in the TCLP extracts were close to or below detection limits of 0.1 mg/L. Aerobic and anaerobic microcosm studies indicated no statistically significant degradation of the PAH and freon extractables in the surface soil samples over eight months, suggesting very slow degradation of the accumulated organics following closure of an HWLT site.
19
Saakian, Alexander. "On the question of the evolution of the soils of archaeological sites of the Early Iron Age (Republic of Bashkortostan)." АгроЭкоИнфо 2, no. 44 (March 21, 2021): 9. http://dx.doi.org/10.51419/20212209.
Анотація:
The study examined the physico-chemical parameters on the example of soils of archaeological sites Akberdinsky-II, Shipovsky and Okhlebininsky-II settlements (Kara-abyss culture of the early iron age IV century BC to the turn of the II-I centuries BC). Archaeological sites and the background area of the Park named after M. I. Kalinin (Ufa) are located within the forest-steppe zone on the territory of right-Bank Pribelsky district of the Ufa-Simsky region of the Republic of Bashkortostan. The soil cover of the monuments is represented by dark gray forest loamy soils. Humus reserves and the uniformity coefficient Cu of elementary soil particles are calculated based on physico-chemical parameters. The humus reserves and the uniformity coefficient showed that the modern soils on the surface of archaeological sites are close to the soils of the background undisturbed territory. For buried soils and urbanized horizons on the territory of archaeological sites over the past 2200 – 2400 years, there is no approximation to the background soil in the main parameters. In general, the soil cover of archaeological sites of different ages is a valuable source of information not only about natural phenomena and events of ancient historical epochs, but also about the features of the evolution and genesis of soils. Keywords: SOIL COVER, SOIL EVOLUTION, HUMUS RESERVES, GRANULOMETRIC COMPOSITION, ARCHAEOLOGICAL SITE
20
Gawander, J. S., P. Gangaiya, and R. J. Morrison. "Potassium Studies on Some Sugarcane Growing Soils in Fiji." South Pacific Journal of Natural and Applied Sciences 20, no. 1 (2002): 15. http://dx.doi.org/10.1071/sp02004.
Анотація:
This study investigated the potassium (K) status of sugarcane growing soils in Fiji, using samples taken from fields under cultivation and also from sites that had not been cultivated for at least 30 years. Five sites were on highly weathered oxyhydroxide soils where the total K contents and K retention capacities were generally low. The two less weathered soils containing significant amounts of 2:1 expanding clay minerals had much higher total K and non-exchangeable K. Exchangeable K and soil solution K contents varied significantly, but were generally low for most soils. Exchangeable K contents were lower in the regularly cultivated fields at five sites out of the eight, were higher at 2 sites, while for one site there was no change. These variations may be due to different levels of K input, uptake by crop and losses due to leaching and erosion. The two less weathered soils (Sigatoka and Nawaicoba) had lower contents of both non-exchangeable and exchangeable K in the cultivated soil when compared with the fallow sites suggesting net loss of K due to cultivation. These soils, however, also had high surface negative charge and thus a better capacity to retain K. Since the K requirement of sugarcane is characteristically high and large amounts of K are removed in the harvested crop, K fertilizer practices need to be scrutinized carefully in Fiji.
21
Badamasi, Hamza, Umar Faruk Hassan, and Harami Malgwi Adamu. "Physico-chemical Properties and Heavy metal Contamination Levels of Soils from Riruwai Mining Area, North-western Nigeria." Malaysian Journal of Applied Sciences 7, no. 2 (October 31, 2022): 29–43. http://dx.doi.org/10.37231/myjas.2022.7.2.324.
Анотація:
Mining activities, despite their economic importance, are well documented as one of the most significant sources of heavy metal pollution in the soil. In the present study, the physico-chemical properties and heavy metal contamination levels of the soils around the Riruwai mining area, in north-western Nigeria, were investigated. A total of 60 surface soil samples from four (4) sampling sites, which include 18 from active mine sites, 12 from abandoned mine sites, 21 from farmlands and 9 from control sites, were collected during the dry and rainy seasons. The physico-chemical properties such as pH, electrical conductivity (EC), soil organic matter (SOM), and cation exchange capacity (CEC) were determined using various analytical techniques. The concentrations of heavy metals were analyzed using a Microwave Plasma Atomic Emission Spectrometer (MP-AES), and the measured concentrations were used to evaluate the pollution load index (PLI). The findings of the study revealed that mining activities had a significant impact on the physicochemical characteristics of the soils, with lower pH, CEC, and SOM values in particular in active and abandoned mining sites. The physico-chemical characteristics of soil vary seasonally, with higher values typically reported during the rainy season, except for pH. The concentrations of arsenic, cadmium, lead, and zinc in the soils of the Riruwai mining area exceeded the threshold value recommended by WHO/FAO (2001) in all the sampling locations and seasons, with the exception of the control sites. The PLI values indicated that the soils in active and abandoned mining sites are strongly polluted by heavy metals, while farmland soils are moderately polluted and control site soils are unpolluted. The soils in the study area are significantly contaminated by heavy metals, particularly in active and abandoned mining sites, and the contamination has spread to farmland, suggesting a significant need for proper containment of heavy metal pollution levels in the area, particularly arsenic, cadmium, lead, and zinc.
22
Yu, Xiangpeng, Kai Cui, Xue Hu, Qian Qiao, and Guojun Zhang. "Properties and Compatibility Assessment of the Slurry with Quicklime for Fissure Restoration of Earthen Sites in Northwest China." Coatings 12, no. 9 (August 27, 2022): 1255. http://dx.doi.org/10.3390/coatings12091255.
Анотація:
Slurries with quicklime for fissure restoration in earthen sites in northwest China can reduce dry shrinkage and reinforce the soil on both sides of fissure. However, their full-scale properties need to be investigated and a compatibility assessment needs to be carried out in order to proceed with further research. The paper pays attention to the full-scale properties of the slurry and typical site soils. A total of 3 slurries with different mix proportions and 35 earthen sites in northwest China are selected to test properties, including basic physical properties, mechanical properties, thermal properties, and water-physical properties. The test results show the properties of the slurries are close and that the properties of the site soils are obviously different. Then, a compatibility assessment is considered as a multi-criteria decision-making problem to solve. Three universal and necessary steps in the paper are to select assessment indicators, weigh each indicator, and sort all of the samples. The AHP, CRITIC, and TOPSIS methods are adopted in the process of the compatibility assessment. The results of assessment show that most site soils are commonly or highly compatible with three slurries; few site soils are very highly or lowly compatible; and that no site soils are very lowly compatible, which means that the three slurries with quicklime with different mix proportions are acceptable for most earthen sites in NW China. The paper provides much basic data of the slurries with quicklime and site soils widely distributed in arid region in NW China, and also builds a model of the compatibility assessment which has potential for the further application of slurries with quicklime.
23
Morugán-Coronado, A., V. Arcenegui, F. García-Orenes, J. Mataix-Solera, and J. Mataix-Beneyto. "Application of soil quality indices to assess the status of agricultural soils irrigated with treated wastewaters." Solid Earth 4, no. 1 (March 7, 2013): 119–27. http://dx.doi.org/10.5194/se-4-119-2013.
Анотація:
Abstract. The supply of water is limited in some parts of the Mediterranean region, such as southeastern Spain. The use of treated wastewater for the irrigation of agricultural soils is an alternative to using better-quality water, especially in semi-arid regions. On the other hand, this practice can modify some soil properties, change their relationships and influence soil quality. In this work two soil quality indices were used to evaluate the effects of irrigation with treated wastewater in soils. The indices were developed studying different soil properties in undisturbed soils in SE Spain, and the relationships between soil parameters were established using multiple linear regressions. These indices represent the balance reached among properties in "steady state" soils. This study was carried out in four study sites from SE Spain irrigated with wastewater, including four study sites. The results showed slight changes in some soil properties as a consequence of irrigation with wastewater, the obtained levels not being dangerous for agricultural soils, and in some cases they could be considered as positive from an agronomical point of view. In one of the study sites, and as a consequence of the low quality wastewater used, a relevant increase in soil organic matter content was observed, as well as modifications in most of the soil properties. The application of soil quality indices indicated that all the soils of study sites are in a state of disequilibrium regarding the relationships between properties independent of the type of water used. However, there were no relevant differences in the soil quality indices between soils irrigated with wastewater with respect to their control sites for all except one of the sites, which corresponds to the site where low quality wastewater was used.
24
Adunoye, G. O., A. O. Oyelere, and M. T. Oladepo. "Investigation of Soils and Bearing Capacity in Selected Construction Sites." Archives of Current Research International 24, no. 5 (May 31, 2024): 416–26. http://dx.doi.org/10.9734/acri/2024/v24i5719.
Анотація:
Considering the importance of soil and foundation in the construction of engineering structures, it is important to investigate the bearing capacity of engineering soils. The purpose of this study was to examine the soils' carrying capacity in southwest Nigeria's Ife-East Local Government Area. Samples of soil were taken from a few chosen construction sites in the research region. Preliminary and geotechnical tests, including triaxia, Atterberg limits, specific gravity, natural moisture content, and particle size measurement, were performed on the soil samples using standard protocol. The bearing capacity of the soil samples was computed for different footing types (circular. square and strip footings) using Terzaghi’s bearing capacity equations. Results showed that all the soils fell into A-2-4 group, according to American Association of State Highway and Transportation Officials (AASHTO) classification standard. Also, using Unified Soil Classification System (USCS), it was observed that 75 % of the samples were well-graded sand (SW) and 25 % were poorly graded sand (SP). For square footing, the bearing capacity values ranged from 269.12 KN/m2 to 3340.85 KN/m2; for circular footings, the values ranged from 267.90 KN/m2 to 3313.47 KN/m2; and for strip footings, the values ranged from 221.58 KN/m2 to 2700.54 KN/m2. It was concluded that all the tested samples were c-ɸ soils, and all the soils could be described as excellent to good foundation materials. The study confirms the fact that the values of bearing capacity are influenced by the nature of foundation soil and shape. and circular footing was found to have intermediate magnitude in all cases.
25
Wurtz, Tricia L. "Understory alder in three boreal forests of Alaska: local distribution and effects on soil fertility." Canadian Journal of Forest Research 25, no. 6 (June 1, 1995): 987–96. http://dx.doi.org/10.1139/x95-107.
Анотація:
The distribution and effects on soil chemistry of shrub alders (Alnus spp.) occurring in the understory of the boreal forest of Alaska were examined. Understory alder ramet distribution was mapped on three sites; ramet density ranged from 150 to 5280 ramets/ha. Allometric biomass models were developed for alder ramets; maps of the spatial distribution of ramets and of estimated aboveground alder biomass are presented. Biomass of alders in the understory ranged from 20 to 690 g•m−2. The total nitrogen of soils collected beneath alder and from areas without alder differed among the three sites and between two sampling episodes. In undisturbed forest, alder soils tended to have more nitrogen than nonalder soils. On the two sites where background soil fertility was low, a greenhouse bioassay matched these results: alder soils had greater nutrient-supplying capacity than nonalder soils. In soil collected after the sites were harvested, however, results varied. Areas that had supported dense alder before harvesting had more soil nitrogen than areas with no alder at only one site, and at another site, alder soils had significantly less total nitrogen. This study suggests that the effect of understory alders on the boreal forest soil mosaic is a function of site characteristics such as canopy openness and soil background fertility.
26
Wiseman, P. Eric, and Christina Wells. "Soil Inoculum Potential And Arbuscular Ycorrhizal Colonization Of Acer Rubrum In Forested And Developed Landscapes." Arboriculture & Urban Forestry 31, no. 6 (November 1, 2005): 296–302. http://dx.doi.org/10.48044/jauf.2005.038.
Анотація:
Arbuscular mycorrhizal fungi (AMF) form a symbiotic relationship with numerous landscape tree species and can improve tree growth and environmental stress tolerance. Construction-related soil disturbance is thought to diminish AMF colonization of transplanted trees in newly developed landscapes. We gathered root, soil, and foliar data from red maples (Acer rubrum) growing in newly developed landscape sites and adjacent native forest sites to test two independent hypotheses: (1) landscape trees show lower levels of AMF colonization than forest trees, and (2) the AMF inoculum potential of landscape soils is lower than that of forest soils. Fine roots sampled from landscape maples had significantly lower AMF colonization than maples from adjacent forest sites (3% versus 22%). However, soilsand mixtures made from landscape soils possessed greater AMF inoculum potential than those made from forest soils (10% versus 4%). Forest soils were more acidic and possessed less extractable P than landscape soils, and differences in AMF colonization between field and landscape maples appeared to reflect differences in soil chemical properties rather than in inoculum potential. The results of this study suggest that not all disturbed landscape soils are deficient in AMF propagules.
27
DASOG, G. S., D. F. ACTON, A. R. MERMUT, and E. DE JONG. "SHRINK-SWELL POTENTIAL AND CRACKING IN CLAY SOILS OF SASKATCHEWAN." Canadian Journal of Soil Science 68, no. 2 (May 1, 1988): 251–60. http://dx.doi.org/10.4141/cjss88-025.
Анотація:
Clay soils in Saskatchewan were studied to understand their shrink-swell potential, to identify soil properties that predict the coefficient of linear extensibility (COLE), and to assess the extent of cracking during the growing season. The soils have medium to very high shrink-swell potential, which is related to the specific surface area associated with expandable clays. Because expandable clays in these soils are predominantly of fine clay size, COLE is reasonably well predicted from percent fine clay. The extent of cracking is estimated for some sites using an improved method of measurement. Limited data suggest that cracking intensity in native grassland is less than in cultivated sites and that, under wheat, it is more pronounced in subarid than in subhumid sites. The magnitude of cracking in clay soils of Saskatchewan is much lower than in warmer regions of the world. It is suggested that COLE values and the extent of cracking could be used in improving the classification of clay soils. Key words: Clay soils, COLE, shrink-swell potential, shrinkage, cracking, Saskatchewan
28
Wiseman, P. Eric, and Christina Wells. "(115) Soil Inoculum Potential and Mycorrhizal Colonization of Acer rubrum in Forested and Developed Landscapes." HortScience 40, no. 4 (July 2005): 1079D—1079. http://dx.doi.org/10.21273/hortsci.40.4.1079d.
Анотація:
Arbuscular mycorrhizal fungi (AMF) form a symbiotic relationship with numerous landscape tree species and can improve tree growth and environmental stress tolerance. Construction-related soil disturbance is thought to diminish AMF colonization of transplanted trees in newly developed landscapes. We gathered root, soil, and foliar data from red maples (Acer rubrum) growing in newly developed landscape sites and adjacent native forest sites to test the hypotheses that: 1) landscape trees show lower levels of AMF colonization than forest trees; and 2) the AMF inoculum potential of landscape soils is lower than that of forest soils. Fine roots sampled from landscape maples had significantly lower AMF colonization than maples from adjacent forest sites (3% vs. 22%; P= 0.0002). However, soil-sand mixtures made from landscape soils possessed greater AMF inoculum potential than those made from forest soils (10% vs. 4%; P= 0.0081). Forest soils were more acidic and possessed less extractable P than landscape soils, and differences in AMF colonization between forest and landscape maples appeared to reflect differences in soil chemical properties rather than in soil inoculum potential.
29
Kibria, MG, MJ Ahammad, and KT Osman. "Soil fertility status of some mango orchards in Chittagong Hill Tracts." Chittagong University Journal of Biological Sciences 6, no. 1-2 (December 2, 2013): 187–97. http://dx.doi.org/10.3329/cujbs.v6i1-2.17244.
Анотація:
Major physico-chemical properties of mango orchard soils (Mangifera indica L.) in different sites of three hill districts, Rangamati, Khagrachari and Bandarban were evaluated. Soils were sandy loam in texture at all the sites except foot hill soil of Shapchari. Soil pH, organic matter, total N and available P varied from 4.76 to 5.58, 1.43 to 2.49 %, 0.10 to 0.16 %, 0.86 mg kg-1 to 2.69 mg kg-1 soil, respectively in surface soil of different sites of mango orchard. 1N NH4OAc extractable K+, Ca2+ and Mg2+ ranged from 0.35 to 0.82, 2.50 to 3.66 and 0.60 to 1.57 cmol kg-1 of soils. Soil pH, organic matter, total N and available P varied significantly among the slope positions within the sites. Similar results were found in case of 1N NH4OAc extractable K+, Ca2+ and Mg2+. The soils are generally poor in organic matter and nutrients. DOI: http://dx.doi.org/10.3329/cujbs.v6i1-2.17244 The Chittagong Univ. J. B. Sci.,Vol. 6(1&2):187-197, 2011
30
Brygadyrenko, Viktor. "Evaluation of ecological niches of abundant species of Poecilus and Pterostichus (Coleoptera: Carabidae) in forests of steppe zone of Ukraine." Entomologica Fennica 27, no. 2 (August 20, 2019): 81–100. http://dx.doi.org/10.33338/ef.84662.
Анотація:
This article analyses abundances of seven Poecilus and Pterostichus species sampled from 836 forest sites located in five geographical regions of the steppe zone of Ukraine. The abundances are analysed in relation to eight forest conditions. New information about associations of the following five species was found. Poecilus versicolor was most abundant in sparse forest sites and on moist sandy soil. Pterostichus melanarius reached its maximum abundance on sites with a thick litter layer, mesohygrophilous condition, clay soils and a sparse herbaceous layer. Pterostichus niger reached maximum abundance in forests with mesohygrophilous and hygrophilous conditions and on sandy loam soils. Abundance of Pterostichus oblongopunctatus was at the highest on sites with a closed tree canopy, a thin litter layer and loamy soils of average salinity. Pterostichus ovoideus was most abundant in forests with low to average litter depth, hygrophilous conditions and loamy soils oflow to average salinity. For Poecilus sericeus and Poecilus cupreus the results ofthis study agreed with the published information.
31
Vilček, Jozef, and Karol Kováč. "Sites Availability for Minimalizing and Soil-Conservation Tillage of Soils in Slovakia." Agriculture (Polnohospodárstvo) 57, no. 2 (June 1, 2011): 68–75. http://dx.doi.org/10.2478/v10207-011-0008-x.
Анотація:
Sites Availability for Minimalizing and Soil-Conservation Tillage of Soils in SlovakiaThere is an alternative technology of traditional agricultural soil processing, so called minimalizing cultivation, which is based on reduction of some operating processes used in common. It is possible to perform this technology only in particular soil conditions. Total land area of sites, which are avail-able for the application of minimalizing cultivation is about 693 thousand hectares, which presents approximately 28% of agricultural and 48% of arable soils. 60% of this land area occurs in the maize production area and 39% in the sugar beet production area, thus in the most favourable agricultural local-ities regarding climate and soil. According to the administrative structuring of Slovakia 43% of agricultural soils suitable for minimalizing technologies occurs in Nitra district and about 27% in Trnava district. Identification of areas, suitable for such technologies application, is possible by the information databases of Soil Science and Conservation Research Institute, which have been elaborated for this purpose in geographic and informative systems. Regarding input parameters, they were chosen as follows: climatic conditions of given locality, steepness, depth, stoniness and soil texture.
32
Woinarski, J. C. Z., A. Fisher, and D. Milne. "Distribution patterns of vertebrates in relation to an extensive rainfall gradient and variation in soil texture in the tropical savannas of the Northern Territory, Australia." Journal of Tropical Ecology 15, no. 4 (July 1999): 381–98. http://dx.doi.org/10.1017/s0266467499000905.
Анотація:
The abundance, richness and species composition of frog, reptile, bird and mammal faunas varied along an extensive gradient from 470 to 1406 mm annual rainfall, and between three contrasting soil types (clay, loam and sand) in northern Australia. Patterns varied between and within vertebrate classes. In general, the most fertile soils in the highest rainfall sites supported the greatest species richness and abundance, but this association with fertility broke down at lower rainfall sites. Frogs were richest and most abundant at high rainfall sites, especially on clay soils, presumably because these had greatest water availability. Clay soils supported few reptile species, but these were often at relatively high abundance. High rainfall sites supported the richest reptile faunas. On sand and loam soils, bird species richness varied little along the rainfall gradient, but richness declined very substantially on clay soils. This was probably largely due to the far more marked vegetation structural change on clay soils than on other substrates. Few mammals were reported, and no clear trends were associated with either rainfall gradient or soil texture. Turnover in species composition along the rainfall gradient was gradual and limited on sand and loam soils, but far more marked on clay soils. There were few cases of replacements of ecologically comparable species along the gradient. These patterns reflect the disparate history, fragmentation and landscape positioning of clay soil environments, relative to the far more homogeneous eucalypt-dominated vegetation on sand and loam soils. Although comparable studies are lacking on other continents, patterns revealed here may be idiosyncratic due to the virtual monopolisation by eucalypts of the environment across the very extensive rainfall gradient.
33
Roy, Julie L., and William B. McGill. "Characterization of disaggregated nonwettable surface soils found at old crude oil spill sites." Canadian Journal of Soil Science 78, no. 2 (May 1, 1998): 331–44. http://dx.doi.org/10.4141/s97-039.
Анотація:
We characterized some of the physical, chemical, and microbiological properties of soils that have become severely water-repellent and disaggregated several years or decades following oil contamination. A growing number of patches (usually <2 ha) of disaggregated water-repellent soils have recently been discovered throughout the province of Alberta at 20 to 50-yr-old crude oil spill sites. The disaggregated water-repellent soil is usually confined to a dry and powdery surface layer 10 to 15 cm deep, which no longer smells, feels, or looks like it contains any oil. These soils appear to have permanently lost the ability to support plant growth and recover through natural processes. We analyzed samples of disaggregated water-repellent and adjacent normal soils from three old crude oil spill sites to provide a background set of information about these poorly known soils and assist in the development of hypotheses concerning the development and persistence of soil water repellency and structural degradation. Compared with normal adjacent soils, disaggregated nonwettable soils are characterized by: (1) a strong resistance to wetting, as determined by the molarity of ethanol droplet (MED) test; (2) a smaller population of viable and culturable microorganisms, which contains at least some representatives from nonspore-forming bacterial genera; (3) a high content of mineral N and total C, a comparable pH and ratio of exchangeable cations, but a lower cation exchange capacity; (4) a slightly lower clay content, as determined by the Bouyoucos hydrometer method; (5) a comparable water desorption behaviour following forced saturation with water; (6) dry aggregates of a smaller mean weight diameter (MWD), as determined by dry sieving and scanning electron miscroscopic (SEM) analyses; (7) slightly less pronounced thermal reactions when heated up to 525 °C, as determined by differential thermal analyses (DTA); and (8) a reduced ability to support plant growth. From these observations, we infer that disaggregated water-repellent soils found at old crude oil spill sites do not differ appreciably from normal adjacent soils in terms of their inorganic chemistry. Nonwettable and adjacent wettable soils differ mostly in terms of some physical and biological characteristics, which probably stem from differences in the quality of the organic matter they contain. Key words: Crude oil spills, petroleum hydrocarbons, soil water repellency, soil disaggregation, soil hydrophobicity
34
Inderjit, Inderjit, Surinder Kaur, and K. M. M. Dakshini. "Determination of allelopathic potential of a weed Pluchea lanceolata through a multifaceted approach." Canadian Journal of Botany 74, no. 9 (September 1, 1996): 1445–50. http://dx.doi.org/10.1139/b96-174.
Анотація:
The allelopathic potential of soils from four sites infested with the weed Pluchea lanceolate (DC.) C.B. Clarke (Asteraceae) was investigated. All sites had similar precipitation, similar crops, and weeds in addition to P. lanceolata. The objectives of this study were threefold: first, variations in the allelopathic effects of P. lanceolata infested soils on growth of three crops; second, soil phenolic content as a result of P. lanceolata infestation; and third, if the chemical characteristics and mycoflora of soils and biotic characteristics of P. lanceolata are responsible for the differences in allelopathic potential. Allelopathic effects of P. lanceolata infested soils were assessed on seedling growth of onion, cucumber, and turnip. Qualitative variation in the soil phenolic content from the four P. lanceolata infested sites was observed. No significant differences in soil mycoflora, soil nutrients, and P. lanceolata biotic characteristics were observed. Growth experiments showed mat crops demonstrated variation in allelopathic response to the soils from the four P. lanceolata infested sites. The present study indicates mat in natural field conditions, allelopathic potential of P. lanceolata varies because of agricultural practices specific to each site. Keywords: allelopathy, Asteraceae, interference, phenolics, soil nutrients, weed.
35
Alves, M. E., and A. Lavorenti. "Potassium - calcium exchange in electropositive oxisols: description of exchange sites." Soil Research 41, no. 8 (2003): 1423. http://dx.doi.org/10.1071/sr03010.
Анотація:
Potassium–calcium exchange was studied in batch experiments carried out with 2 oxisols exhibiting positive charge balance. The experimental data were quantitatively described with the Rothmund–Kornfeld formulation of the Gaines–Thomas approach, and the permanent and variable surface negative charges were measured using the caesium-adsorption method. For both soils, no appreciable involvement of permanent negative charges was observed in the potassium–calcium exchange, which, in turn, seemed to occur solely on the variable negative charges. The preference for potassium over calcium exhibited by both soils was well described by the Rothmund–Kornfeld formulation of the Gaines–Thomas approach. It was hypothesised that the exchange sites could be divided into 2 groups with different potassium selectivities. The proportions and selectivities of these exchange site groups were estimated combining the Rothmund–Kornfeld formulation with the Dufey–Delvaux multisite model. For both soils, there was excellent agreement between experimental and modelled data and it was possible to estimate the amounts of exchange sites (cmolc/kg) presenting greater and lower potassium selectivity. The existence of variable negative charge pools more accessible to K than to Ca ions but not evenly accessible to the former was considered as a possible cause of the non-ideal behaviour of the studied soils in relation to the potassium–calcium exchange.
36
Moles, Norman, Richard Moles, and Grace O'Donovan. "Evidence for the Presence of Quaternary Loess-Derived Soils in the Burren Karstic Area, Western Ireland." Irish Geography 28, no. 1 (January 14, 2015): 48–63. http://dx.doi.org/10.55650/igj.1995.412.
Анотація:
Quaternary loess-derived soils are found in many mid-latitude countries. Extensive loess deposits have not been described from Ireland except in unpublished reports of possible loessic soils (“stone-free drift”) on karstic terrain in die Burren, Co. Clare. The objective of this study is to verify or discount the presence of loess-derived soils in the Burren. Data on particle size, mineralogy and bulk geochemistry are presented for 14 soil samples from 12 sites, including 6 from areas which unpublished studies had identified (in map form) as covered by stone free drift. Most samples comprise silly clay soils (up to 58% sill) with low carbonate contents and low organic carbon contents. With regard to the carbonate-poor samples, XRD and XRF analyses enabled two groups to be distinguished. Group A soils show characteristics consistent with weathered till, while Group B soils show characteristics consistent with weathered loess. All sites falling within areas mapped as possible loess in previous studies provided samples which were assigned to group B. while group A soils were mapped as till or rendzina. Samples from two sites previously mapped as loess, which are relatively rich in silica and sill-sized particles, are the strongest candidates for being largely of loessic origin. These findings strongly support the view that scattered, weathered, aeolian deposits are found in upland karstic sites within the Burren. but further work is needed to confirm their extent.
37
Bennett, D. Rodney, Frank J. Hecker, Toby Entz, and Graeme M. Greenlee. "Salinity and sodicity of irrigated Solonetzic and Chernozemic soils in east-central Alberta." Canadian Journal of Soil Science 80, no. 1 (February 1, 2000): 117–25. http://dx.doi.org/10.4141/s99-042.
Анотація:
A 4-yr study was conducted on irrigated Solonetzic and Chernozemic soils in the Berry Creek Basin of east-central Alberta to assess changes in soil salinity and sodicity during irrigated alfalfa production and to evaluate the suitability of Solonetzic soils for irrigation. Two of the study sites consisted mainly of soils classified as Solodized Solonetz, with at least 70% in the Solonetzic order. Two chernozemic sites were almost exclusively Chernozemic soils. A significant increase in soil salinity occurred in the A horizon at one solonetzic site and at both chernozemic sites and in the B horizon of one chernozemic site. Mean electrical conductivity (ECe) in these horizons for all irrigation treatments was less than or equal to 1 dS m−1. Soil sodicity also increased significantly in the A horizon at one solonetzic site, and in the A and B horizons of both chernozemic sites. The mean sodium adsorption ratio (SAR) of the A horizon at this solonetzic site was 2.9, 4.8, 4.4 and 5.0 for the control, low, medium and high irrigation treatments, respectively. The SAR in the A horizon at the chernozemic sites was less than 2.6 for all the irrigation treatments. Increases in soil salinity and sodicity were attributed to the chemistry and amount of irrigation water used at each site. Salinization and sodification in addition to the changes associated with the quality and quantity of irrigation water were not evident at any of the sites. The two-cut yield of alfalfa from the solonetzic sites in the third year of growth was about 25% less than from the chernozemic sites and was below the acceptable yield range for irrigated alfalfa in southern Alberta. Our results confirm existing land classification standards in Alberta that exclude solonetzic landscapes from irrigation development where more than about 30% of the soils have an SAR value greater than 12 in any soil horizon within 1 m of the surface. Key words: Solonetzic soils, irrigation suitability, soil salinity, soil sodicity, irrigated alfalfa
38
Kogan, Marcelo, Alejandra Metz, and Rodrigo Ortega. "Adsorption of glyphosate in chilean soils and its relationship with unoccupied phosphate binding sites." Pesquisa Agropecuária Brasileira 38, no. 4 (April 2003): 513–19. http://dx.doi.org/10.1590/s0100-204x2003000400010.
Анотація:
The objective of this work was to investigate glyphosate adsorption by soils and its relationship with unoccupied binding sites for phosphate adsorption. Soil samples of three Chilean soils series - Valdivia (Andisol), Clarillo (Inceptisol) and Chicureo (Vertisol) - were incubated with different herbicide concentrations. Glyphosate remaining in solution was determined by adjusting a HPLC method with a UV detector. Experimental maximum adsorption capacity were 15,000, 14,300 and 4,700 mg g¹ for Valdivia, Clarillo, and Chicureo soils, respectively. Linear, Freundlich, and Langmuir models were used to describe glyphosate adsorption. Isotherms describing glyphosate adsorption differed among soils. Maximum adjusted adsorption capacity with the Langmuir model was 231,884, 17,874 and 5,670 mg g-1 for Valdivia, Clarillo, and Chicureo soils, respectively. Glyphosate adsorption on the Valdivia soil showed a linear behavior at the range of concentrations used and none of the adjusted models became asymptotic. The high glyphosate adsorption capacity of the Valdivia soil was probably a result of its high exchangeable Al, extractable Fe, and alophan and imogolite clay type. Adsorption was very much related to phosphate dynamics in the Valdivia soil, which showed the larger unoccupied phosphate binding sites. However relationship between unoccupied phosphate binding sites and glyphosate adsorption in the other two soils (Clarillo and Chicureo) was not clear.
39
Zamin, Bakht, Hassan Nasir, Muhammad Ali Sikandar, Waqas Ahmad, Beenish Jehan Khan, Mahmood Ahmad, and Muhammad Tariq Bashir. "Comparative Study on the Field- and Lab-Based Soil-Water Characteristic Curves for Expansive Soils." Advances in Civil Engineering 2022 (May 2, 2022): 1–9. http://dx.doi.org/10.1155/2022/6390442.
Анотація:
Expansive soils are problematic and viewed as a potential hazard for buildings and structures due to swell and shrink phenomena. The damaging effect of these soils is strongly correlated with the soil-water characteristics of expansive soils present in the shallow depth. The seasonal wetting-drying cycle is vital in fluctuating moisture content in the surficial soils. As such, soils remain unsaturated most of the time due to high absorption capacity. Therefore, it is crucial to assess them as unsaturated soil, and the soil-water characteristic curve (SWCC) is an essential tool for measuring unsaturated soils’ mechanical and hydraulic properties. The main objective of this study was to establish both field- and lab-based SWCCs for the expansive soils and compare them for determining the possible difference between them. For this purpose, eight sites of expansive soils were selected for sampling and in situ testing. These sites include three locations of Karak, three locations of Kohat, and two locations of D.I areas. Based on the experimental results, Karak’s expansive soil indicated a high suction value of 705 kPa, while D. I Khan’s soil showed the least suction equal to 595 kPa. The comparison of field and lab SWCCs for the potential sites presented a close agreement in the matric suction values beyond the air entry values (AEVs), particularly in the residual suction zones. It was also concluded that for expansive soils, the field- and lab-based SWCCs are comparable beyond the AEVs. The established curves can be successfully utilized to assess local expansive soils in the framework of unsaturated soils.
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Chueva, Natalya V., Galina M. Kashulina, and Natalya M. Korobeynikova. "Agrochemical properties of soil of the Polar-Alpine Botanical Garden-Institute." Transaction Kola Science Centre 12, no. 6-2021 (December 31, 2021): 287–91. http://dx.doi.org/10.37614/2307-5252.2021.6.12.9.043.
Анотація:
The current state of soil fertility was estimated at 2 sites of experimental fields of the Polar-Alpine Botanical Garden. Soils in both areas are characterized by a light granulometric composition. The sites vary in the content of organic matter in the soils, as well as the acidity and proportion of the sites where the liming is needed. The availability of phosphorus at all sites in both areas is characterized as high, potassium — from medium to high, mineral forms of nitrogen — as very low.
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Nesvetaev, Mikhail Yuriyevich, Denis Ivanovich Gubarev, Irina Igorevna Demakina, Vladimir Alexandrovich Tarbaev, and Konstantin Evgenievich Denisov. "Influence of agroecological conditions on the productivity of zone landscapes of the Saratov region." Agrarian Scientific Journal, no. 12 (December 29, 2021): 45–49. http://dx.doi.org/10.28983/asj.y2021i12pp45-49.
Анотація:
The article reveals the features of the watershed and slope natural boundaries of the northern, typical and arid steppe. For the soils of test sites No. 5 (Saratov) and No. 9 (Krasny Kut), a higher content of mobile forms of phosphorus and potassium was revealed on the northern slopes, in contrast to the southern slopes. The soils of the northern slopes of test sites No. 1 (Arkadak) is less supplied with macronutrients than soils of southern expositions. Plakor soils on test sites No. 1, No. 5 are better than slope tracts provided with K2O, but worse than P2O5. Soil productivity of watershed types of tracts of test sites No. 1, No. 5 are above the slopes. Northern slopes of test sites No. 1 are less productive than the southern ones. On test sites No. 5, on the contrary, the northern slopes are more productive than the southern ones. On test sites No. 9 southern slopes are more productive than watersheds and northern slopes. The dependence of the SCC in the phase of tube-heading and the future harvest was revealed. An increase in the hydrothermal index from 0.3 to 0.45 in this phase of wheat development under conditions of the test sites No. 5 gave a 2-fold increase in yield. The quality of spring soft wheat grown on the slopes of the southern exposure is higher than on the watersheds and slopes of the northern exposure for all objects of study.
42
Li, Xinyu, Xu Li, Jian Wang, Xiujuan Wang, Jian Sun, Zhencheng Su, Huiwen Zhang, and Peijun Li. "Profiles ofMycobacteriumcommunities under polycyclic aromatic hydrocarbon contamination stress in the Shenfu Irrigation Area, northeast China." Canadian Journal of Microbiology 59, no. 10 (October 2013): 694–700. http://dx.doi.org/10.1139/cjm-2013-0185.
Анотація:
Indigenous Mycobacterium communities play an important role in the degradation of polycyclic aromatic hydrocarbons (PAHs), but little is known about Mycobacterium distribution in situ at PAH-contaminated sites. In this study, the diversity and distribution of Mycobacterium communities were investigated in sediments and soils at sites upstream, midstream, and downstream of an oil-sewage irrigation channel, using denaturing gradient gel electrophoresis (DGGE). The results show that heavy PAH contamination in upstream sites negatively affected Mycobacterium community diversity compared with midstream and downstream sites in all 3 sample types (sediments, corn field soils, and rice field soils). There was a correlation between the distribution of Mycobacterium communities and PAH contamination, as indicated by canonical correspondence analysis. Mycobacterium diversity and distribution was found to vary between the 3 sample types.
43
Kennedy, Sarah A., and Sarah J. Kelloway. "Heavy Metals in Archaeological Soils." Advances in Archaeological Practice 9, no. 2 (March 18, 2021): 145–59. http://dx.doi.org/10.1017/aap.2020.52.
Анотація:
AbstractPortable X-ray fluorescence (pXRF) spectroscopy is commonly used for testing toxic levels of heavy metals in modern industrial waste sites, and it has seen growing applicability in the context of archaeological survey and soils. In this study, we present the results of our pXRF analysis of surface soils at a historic silver refinery located near Puno, Peru, in the western Lake Titicaca Basin. The results of our analysis identified hazardous levels of antimony (Sb), arsenic (As), mercury (Hg), and lead (Pb) in excavation soils, necessitating the relocation of planned excavation units and the use of personal protective equipment. This study highlights the advantages of rapid, in situ pXRF analysis of surface soils in contaminated industrial archaeology sites to assess potential harm to human health.
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Uddin, MJ, Arafat Rahman, AHM Zulfiquar Ali, and Md Khalilur Rahman. "Estimation of Carbon Stock in the Sylhet Basin Soils of Bangladesh." Journal of the Asiatic Society of Bangladesh, Science 46, no. 1 (June 22, 2021): 49–60. http://dx.doi.org/10.3329/jasbs.v46i1.54228.
Анотація:
Wetland basin soils are the major store houses of organic carbon where there is a scope to use this carbon in mitigating the climate change. A study was conducted in these basin soils at 100 cm depth regarding their carbon stock. The study showed that total soil organic carbon (SOC) stock in the Sylhet basin soils of Bangladesh is 0.094 Pg where the SOC stock was 0.044 Pg in medium low land sites and it was about 0.050 Pg in lowland sites. There was no previous study on SOC stock in the Sylhet basin soils of Bangladesh. These may act as benchmark SOC stock datasets for the future agricultural planning. The soil organic carbon stock is higher in the lowland than medium lowland sites. The contents of SOC are low is compared to its threshold levels. Moreover, it is apprehended that basin soils may lose their carbon due to the decrease of inundation level by climate change, and other eco-environmental changes. So, it is very much urgent to take steps in preserving the organic carbon of lowland basin soils.
Asiat. Soc. Bangladesh, Sci. 46(1): 49-60, June 2020
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Michée, Ilonga Bofole, Kongolo Merveille, Kisimba Trésort, Kiteba Mikinzi Serge, and Mputu Kanyinda Jean-Noël. "Assessment of Soil Pollution by Metallic Trace Elements (MTE): Case of Environment of Ruashi Mining/Haut-Katanga (DR Congo)." European Journal of Environment and Earth Sciences 4, no. 1 (February 24, 2023): 69–72. http://dx.doi.org/10.24018/ejgeo.2023.4.1.338.
Анотація:
The main objective of this research was to assess the level of soil contamination of Ruashi Mining sites and its surroundings by metallic trace elements. The samples of the soils studied were taken during the month of June 2020. The clod of earth was taken at a depth of 20 cm and 40 cm by a manual auger and was packed in a plastic bag before the analyzes in the laboratory. After drying, they were ground and then sieved to 2 mm mesh. The Cd, Cr, Co, Cu and Zn were determined by X-ray fluorescence spectrometry (XRF). The results showed that all the soils of the Ruashi sites were amply contaminated by Co, the soils of Ruashi 1 and 3 are contaminated with Cr while the soils of theR uashi 4 are contaminated with Cu. The study of the pollution index revealed that the soils of the Ruashi have multiple contamination because the PI is greater than 1 except for the soils of the Ruashi 4 whose PI value is 0.97. Hence it is imperative to protect the ecosystems surrounding the mining sites of the Ruashi.
46
Chai, Xin Jun, Chun Feng He, and Yan Sheng Gao. "Unconfined Compression Strength of Tianluoshan Relic Soils Solidified by Silicone." Advanced Materials Research 610-613 (December 2012): 2908–11. http://dx.doi.org/10.4028/www.scientific.net/amr.610-613.2908.
Анотація:
Tianluoshan relic sites is a typical earthen sites located at moisture circumstances. The potential application of silicone for strengthening Tianluoshan relic soils were evaluated by a series of unconfined compression tests. The main considered influence factors includue: curing condition, curing time, and variation of water content. The results show that the compressive strength of Tianluoshan relic soils solidified by silicon increase with curing time, and silicon can effectively improve the strength of Tianluoshan relic soils under constant temperature & moisture condition.
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Mandre, Malle, Mari Tilk, and Priit Kõresaar. "Chemical characteristics of soils in Scots pine forests of Cladina and Vaccinium vitis-idaea site types on coastal dunes of Baltic Sea." Forestry Studies / Metsanduslikud Uurimused 49, no. 1 (January 1, 2008): 5–12. http://dx.doi.org/10.2478/v10132-011-0058-x.
Анотація:
Chemical characteristics of soils in Scots pine forests of Cladina and Vaccinium vitis-idaea site types on coastal dunes of Baltic Sea The coastal dunes of Southwest Estonia have been undergoing a process of stabilisation and are today covered predominantly with Scots pine forests. For the investigation of soils on dunes sampling sites were selected according to topographical positions and forest site types: two sites in Cladina and two sites in Vaccinium vitis-idaea site types on dunes of different heights. The prevailing soils on dunes are Gleyic Podzols, which are generally poor in humus, water and mineral nutrients. Great differences in soil chemical components were found on the foots, slopes and tops of the dunes depending on the height of the dune. The study showed that the concentration of macronutrients (N, K, Ca, Mg) in soil decreased from the foot towards the top. On the other hand, a serious decrease in the nutrient concentration from the O horizon to the BC horizon was typical of the dunes. The soils were generally acidic, with the pH of 3.4-5.5 in the studied sampling sites. The soils were more acidic on the foots of the dune and in the O and A horizons.
48
Bierza, Wojciech, Karolina Bierza, Artur Trzebny, Izabela Greń, Miroslawa Dabert, Ryszard Ciepał, and Lidia K. Trocha. "The communities of ectomycorrhizal fungal species associated with Betula pendula Roth and Pinus sylvestris L. growing in heavy-metal contaminated soils." Plant and Soil 457, no. 1-2 (October 19, 2020): 321–38. http://dx.doi.org/10.1007/s11104-020-04737-4.
Анотація:
Abstract Aims Pioneer tree species such as Betula pendula and Pinus sylvestris encroach soils contaminated with heavy metals (HMs). This is facilitated by ectomycorrhizal fungi colonizing tree roots. Thus, we evaluated the ectomycorrhizal fungal (EMF) communities of B. pendula and P. sylvestris growing in HM-contaminated soils compared to non-contaminated soils. We also studied the effect of HMs and soil properties on EMF communities and soil fungal biomass. Methods Roots of B. pendula and P. sylvestris were collected from three HM-contaminated sites and from two non-contaminated sites located in Poland. EMF species were identified using DNA barcoding. Soil fungal biomass was determined by soil ergosterol. Results B. pendula and P. sylvestris growing in HM-contaminated soils had similar EMF communities, where Scleroderma, Rhizopogon and Russula as well as ectomycorrhizae of the long-distance exploration type dominated. Among all of the examined soil factors studied, toxicity index (TITotal) was the most significant factor shaping the composition of EMF communities. Despite significant differences in the structure of the EMF communities of trees growing in HM-contaminated sites compared to control sites, no differences in overall diversity were observed. Conclusions Only well-adapted EMF species can survive toxic conditions and form ectomycorrhizal symbiosis with encroaching trees facilitating the forest succession on contaminated soils.
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Zannat, Tasnim, Farhana Firoz Meem, Rubaiat Sharmin Promi, Umme Qulsum Poppy, and MK Rahman. "Soil fertility and leaf nutrient status of litchi orchard sites." Dhaka University Journal of Biological Sciences 30, no. 2 (July 9, 2021): 141–49. http://dx.doi.org/10.3329/dujbs.v30i2.54640.
Анотація:
Twelve soil and twelve leaf samples were collected from twelve litchi (Litchi chinensis Sonn.) orchards from different locations of Dinajpur to evaluate some physico-chemical properties and nutrient status of soil, and concentration of nutrients in litchi leaf. The pH of the soil varied from very strong acidic to medium acidic (4.8 - 5.7), organic matter content varied from 0.84 - 1.88%, EC varied from 302.4 - 310.2 μS/cm. The dominant soil textural class was clay loam. The average particle density was 2.49g/cm3. Total N, P, K and S in soils were 0.053 - 0.180%, 0.02 - 0.07%, 0.046 - 0.370 meq/100 g, and 0.015 - 0.028%, respectively. Available N, P, K, S, Zn, Fe, Mn and B in soils 30.40 - 57.8 mg/kg, 10.53 - 14.33 mg/kg, 0.03 - 0.32 meq/100 g, 20.03-34.80 mg/kg, 0.68-1.50 μg/g, 31.8 - 41.5 μg/g, 6.75 - 7.39 μg/g and 0.25-0.51 μg/g, respectively. The concentration of total N, P, K, S, Zn and Mn in the leaf were 1.74 - 2.20%, 0.11 - 0.188%, 0.104- 0.198%, 0.129 - 0.430%, 12 - 14 μg/g and 30 - 74 μg/g, respectively. The overall results indicated that the fertility status of the soils under the litchi plantation in the Dinajpur area are medium fertile. So, farmers could be advised to grow litchi plants after applying amendments to the soils to improve the physico-chemical properties in the Dinajpur area of Bangladesh.
Dhaka Univ. J. Biol. Sci. 30(2): 141-149, 2021 (July)
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Abdel-Khadir, M. S., A. Dadi Mahamat, Abakar Ali, Mahamoud Y.K, and S. Gaye. "GEOTECHNICAL STUDY AND PHYSICO-CHEMICAL CHARACTERIZATION OF SOILS OF THREE QUARRIES IN THE CITY OF ABECHE IN CHAD." International Journal of Advanced Research 11, no. 05 (May 31, 2023): 318–26. http://dx.doi.org/10.21474/ijar01/16883.
Анотація:
This article focus on the geotechnical and physicochemical studies of soils from three sites in the city of Abéché. The article presents the locations of the sampling sites, experimental devices, and some physical parameters. Prior to the geotechnical study, a physicochemical characterization of soil from different quarries was conducted, including wetting-drying tests, capillary water absorption tests, and desorption isotherms of bricks. Finally, geotechnical characterizations of three soils were performed, including analyses of grain size by sieving and sedimentometry, Atterberg limits, methylene blue tests, and the bulk density of solid particles. The results showed that the different soils were very similar, being of a low-plasticity loam and clay type. The results also showed that the organic matter content in the different soils was very low and that the average pH value of the three sites was around 7.1, which is neutral with a slightly basic tendency.