Готові списки джерел за темами / Poor soil

Добірка наукової літератури з теми "Poor soil"

Автор: Grafiati
Опубліковано: 14 березня 2023

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Статті в журналах з теми "Poor soil"

1

Bestland, Erick A., and Matthew S. Forbes. "Evidence for biocycling from Ba/Ca, Sr/Ca, and 87Sr/86Sr in soils (Red Brown Earths) from South Australia." Soil Research 47, no. 2 (2009): 154. http://dx.doi.org/10.1071/sr08026.

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Анотація:
The impact of elemental cycling and biological fractionation in the soil–vegetation system was investigated for 6 Red Brown Earth soil profiles (Xeralfs and Xerults) from South Australia by comparing geochemical and 87Sr/86Sr data from bulk soils, soil exchange pool, and vegetation (grapes). In all 6 soil profiles from 3 different sites, Ba/Ca ratios of vegetation, soil exchange pool, and bulk soils were found to be a more robust biological fractionation indicator than Sr/Ca ratios. In the base-poor soils of the Coonawarra–Padthaway area of South Australia, the degree of weathering of soil material, as estimated by titania and alumina contents, correlated very well with the biological fractionation indicator Ba/Ca. Soil horizons with greater clay and titania content also had higher degrees of biological fractionation. Similar Red Brown Earth soils 400 km north in the Clare Valley showed either no, or poor, biological fractionation signature in their bulk soil. The Clare Valley soils have a stronger colluvial component and are richer in base cations than the Coonawarra and Padthaway sites. The main source of bulk soil material in the base-poor soils of the Coonawarra–Padthaway areas is dust, which has greatly influenced the base cation concentration, Ba/Ca ratios, and the strontium isotope ratios. Soils from Clare Valley, by comparison, are less intensely weathered and are thus not as dependent on dust and biocycling for their base cations. Biological fractionation has not left a discernible signature on the composition of the bulk soil. The exchange pools at all 3 sites are dominated by wetfall–dryfall sources, which in this coastal area are dominated by marine sources. For the base-poor soils of the Coonawarra–Padthaway area, the most likely major source of aeolian detritus is Murray River mud. The fine-grained component of this mud, with its organic matter content, relatively high base cation concentrations, and low strontium isotope ratios (Douglas et al. 1995) appears to have overwhelmed other dust sources and caused a homogenisation of the geochemical signature of fine-grained bulk soils in this area. Subsequent in situ weathering and neoformation following dust deposition were strongly influenced by exchange phase concentrations and ratios and resulted in an enhanced biological fractionation signature of the soils.
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2

Stapelberg, F. D. J. "Case study in the Northern Cape (Loopeng area), South Africa, confirming occurrence of a collapsible sand soil structure in transported soils." South African Journal of Geology 125, no. 2 (June 1, 2022): 217–24. http://dx.doi.org/10.25131/sajg.125.0014.

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Abstract Testing was performed on transported soils belonging to recently deposited sandy-silty soil deposits occurring in and around Loopeng Village, Northern Cape Province, South Africa, in order to determine the occurrence and order of magnitude of a collapsible sand soil structure. Various empirical geotechnical characteristics including: in situ soil profile structure description, particle grading curve and clay content, soil classification, soil density and void ratio were compared to collapse potential values determined with oedometer testing, in order to judge the success with which the empirical characteristics can be utilised to predict the occurrence of a collapsible soil structure. From the results it is clear that a collapsible sand structure exists in the transported soils (both aeolian and fine alluvial) and that the empirical descriptors mostly correctly indicate the occurrence of the particular soil structure when compared to existing studies on collapsible sands. The one descriptor which reflects a relatively poor prediction of a collapsible soil structure, namely the in situ soil profile structure description, is considered to be a poor indicator due to erroneous or poor in situ soil structure observations. These poor observations result from unfavourable local conditions namely dry, dusty soil conditions and very brief intact standup time of test pit side walls.
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3

Abdullah, Waleed R., and Sali Nabeel Jabrou. "Improving Ionic Exchange Process of Potassium in Poor Soils by Bentonite." IOP Conference Series: Earth and Environmental Science 961, no. 1 (January 1, 2022): 012098. http://dx.doi.org/10.1088/1755-1315/961/1/012098.

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Abstract The current study was carried out to improve ionic exchange for potassium in sandy and gypsiferous soils to obtain an increase in absorption of potassium ions in NPK fertilizers, the improving process includes two stages; The first is adding NPK fertilizer with concentrations (0.020%, 0.040%, and 0.070%) by weight for two samples, the exchange potassium concentration was measured and notice the increasing from 124 ppm to 140 ppm in sandy soil and from156 ppm to 180 ppm in gypsiferous soil when using the highest concentration (0.070%), the second stage included adding grinded bentonite ore (10%, 20%,30%) by weight to the two samples after treated with NPK fertilizer in same concentrations above, potassium exchange increased to 340 ppm in sandy soil and to 450 ppm in gypsiferous soil by using NPK fertilizer and bentonite ore concentrate (0.070% & 30%) respectively.
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4

Lee, Jong-Mun, Do-Gyun Park, Seong-Su Kang, Eun-Jung Choi, Hyo-Suk Gwon, Hyoung-Seok Lee, and Sun-Il Lee. "Short-Term Effect of Biochar on Soil Organic Carbon Improvement and Nitrous Oxide Emission Reduction According to Different Soil Characteristics in Agricultural Land: A Laboratory Experiment." Agronomy 12, no. 8 (August 10, 2022): 1879. http://dx.doi.org/10.3390/agronomy12081879.

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Biochar application has been considered as a promising solution to address the effects of modern agriculture on climate change. However, there is a lack of research on the biochar application of greenhouse gas emissions based on poor soils in Korean agricultural land. Therefore, this study aimed to evaluate the effects of biochar application according to different soil characteristics on soil organic carbon (SOC) improvement and greenhouse gas reduction. The incubation experiments were conducted for 49 days and used different feedstock (barley straw and poultry manure) and biochar application rates (0, 5, 10, and 20-ton ha−1) in four soil characteristics (upland, U; greenhouse, G; converted land, C; reclaimed land, R). The results of this study showed that the SOC increased significantly in all soils after biochar application. The increasing SOC rate was the highest in poor soil. Biochar 20-ton ha−1 treatment significantly reduced N2O emissions by 33.2% compared with the control. Barley straw biochar significantly reduced N2O emissions from all soils. Barley straw biochar decreased approximately 74.5% of N2O emissions compared with poultry manure biochar. Poultry manure biochar improved SOC and reduced N2O emissions in poor soil. However, in poultry manure biochar treatment in U and G soil, N2O emissions increased. In conclusion, barley straw biochar application was found to suppress N2O emissions and improve the SOC in all soil characteristics of agricultural land. In addition, the soil carbon storage effect and N2O reduction effect of biochar were the highest in poor soil. Thus, the biochar application can be a potential agricultural practice for improving soil quality and decreasing N2O emissions in domestic agricultural soil.
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5

Wu, Shenglan, Hongdong Jie, and Yucheng Jie. "Role of Rhizosphere Soil Microbes in Adapting Ramie (Boehmeria nivea L.) Plants to Poor Soil Conditions through N-Fixing and P-Solubilization." Agronomy 11, no. 11 (October 20, 2021): 2096. http://dx.doi.org/10.3390/agronomy11112096.

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Анотація:
The N-fixing and P-solubilization functions of soil microbes play a vital role in plant adaptation to nutrient-deficiency conditions. However, their exact roles toward the adaptation of ramie to poor soil conditions are still not clear. To fill this research gap, the N-fixing and P-solubilization efficiencies of soils derived from the rhizosphere of several ramie genotypes with different levels of poor soil tolerance were compared. Correlations between the N-fixing, P-solubilization efficiency, and the poor soil tolerable index were analyzed to quantify their contributions towards the adaptation of ramie plants to poor soil conditions. To explore how the microorganisms affected the potential of N-fixing/P-solubilization, the activities of the nutrients related the soil enzymes were also tested and compared. The results of this study confirm the existence of N-fixing and P-solubilization bacteria in the ramie rhizosphere of the soil. The number of N-fixing bacteria varied from 3010.00 to 46,150.00 c.f.u. per gram dry soil for the ramie treatment, while it was only 110.00 c.f.u. per gram dry soil for treatment without ramie cultivation. The average P-solubilization efficiency of ramie treatment was almost five times higher than that of the control soil (0.65 vs. 0.13 mg mL−1). The significant correlations between the poor soil tolerance index and the N-fixing bacteria number (r = 0.829)/nitrogenase activity (r = 0.899) suggest the significantly positive role of N-fixing function in the adaptation of ramie plants to poor soil. This is also true for P-solubilization, as indicated by the significant positively correlation coefficients between the ramie poor soil tolerance index and P-solubilization efficiency (0.919)/acid phosphatase activity (0.846). These characteristics would accelerate the application of “holobiont” breeding for improving ramie nutrient use efficiency.
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6

WITCOVER, JULIE, STEPHEN A. VOSTI, CHANTAL LINE CARPENTIER, and TÂMARA CLÁUDIA DE ARAÚJO GOMES. "Impacts of soil quality differences on deforestation, use of cleared land, and farm income." Environment and Development Economics 11, no. 3 (May 17, 2006): 343–70. http://dx.doi.org/10.1017/s1355770x0600283x.

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Анотація:
Preparing regional development strategies for the Amazon Basin is a vexing task for policymakers. Forests continue to fall and agriculture to move in to a region with patchy (in terms of agronomic potential) yet broadly nutrient-poor soils. The spatial distribution of soil types is not well mapped at finer scales relevant for agriculture. There is, moreover, little evidence about how farm land use or farm household welfare varies by soil quality in this frontier setting. Despite these information gaps, regional planners continue to use soils as a basis for policy action, some of which may influence future options for the Amazon. This paper uses a farm-level bioeconomic model that captures soil-quality-specific degrading effects of agricultural activities to assess the impacts of soil quality differences on deforestation, use of cleared land, and smallholder income in the western Brazilian Amazon. Focusing on an archetypical area farm with reasonable market access but limited access to labor and credit, simulations show soil quality mattered more for income than for deforestation or land use, although extremely cash-strapped farmers on poor-quality soils could face displacement. Pasture dominated farm land use across all soil types as farm forest disappeared within a generation on successfully established farms. Good- and (viable) poor-soil farms had slightly slower deforestation rates than their medium-soil counterparts – rich-soil farms shifting small amounts of area (and labor) to the more nutrient- and labor-intensive annuals, and (even viable) poor-soil farms lacking sufficient resources to clear and farm additional land. Farms with good soils could generate about 44 per cent more income than their viable poor-soil counterparts, but the lower-income level still surpassed thresholds for meeting food security and other needs. At no combination of income level and soil quality explored did the (simulated) farmer find it worthwhile to purchase and apply chemical fertilizer; nutrients came instead from secondary forest fallow, whose area rose or fell in step with annual cropping area. The implications of these results for land-use zoning, forest conservation, poverty alleviation, and other policies are discussed.
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7

White, PF, and AD Robson. "Poor soil aeration or excess soil CaCO3 induces Fe deficiency in lupins." Australian Journal of Agricultural Research 40, no. 1 (1989): 75. http://dx.doi.org/10.1071/ar9890075.

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The poor growth and chlorosis suffered by lupins when grown on fine-textured alkaline soils appears primarily related to Fe deficiency which is affected by the level of HCO3-; and CaCO3 in the soil.Plants of Lupinus angustifolius were grown on an alkaline, sandy clay loam which was either acidified or limed. Additionally, plants received either adequate water (field capacity) or excess water to adjust the aeration of the soil.Plant growth was closely related to the concentration of Fe within the young leaves. Liming the soil or watering above field capacity reduced the Fe concentrations in shoots, induced chlorosis and reduced growth. Chlorosis and reduced growth was not caused by Mn deficiency, even though treatments that reduced growth also reduced Mn concentrations in shoots.The lime chlorosis disorder in lupins therefore is primarily caused by an inability of the plants to obtain Fe in calcareous soils and not caused by Mn deficiency or by inactivation of Fe within the shoots.
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8

Courtin, P. J., K. Klinka, M. C. Feller, and J. P. Demaerschalk. "An approach to quantitative classification of nutrient regimes of forest soils." Canadian Journal of Botany 66, no. 12 (December 1, 1988): 2640–53. http://dx.doi.org/10.1139/b88-360.

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Many workers have classified nutrient regimes of forest soils, but there have been few attempts to provide an objective means of defining soil nutrient regimes. This objective was accomplished in the present study by numerical analysis conducted on 195 soil samples of vegetation and soils from coastal British Columbia. The differentiating characteristics used in the classification were pH (H2O) and the C/N ratio of the humus forms; and total soil nitrogen (kg/ha) and sum of exchangeable calcium, magnesium, and potassium (kg/ha) within the soil rooting zone. Numerical analysis distinguished seven soil groups. These groups were related to the floristic composition of understory vegetation and to forest productivity as indicated by site index. These vegetation – soil relationships were then used to assign the soil groups into five soil nutrient regime classes: very poor, poor, medium, rich, and very rich.
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9

Chan, KY, JA Mead, WP Roberts, and PTW Wong. "The effect of soil compaction and fumigation on poor early growth of wheat under direct drilling." Australian Journal of Agricultural Research 40, no. 2 (1989): 221. http://dx.doi.org/10.1071/ar9890221.

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Poor early growth of wheat was studied in a tillage experiment at Cowra, N.S.W., in the 1986 season to determine the involvement of soil physical and biological factors in this problem. A compaction treatment to achieve bulk density and shear strength comparable with those detected in the direct-drilled soils was imposed on the conventionally cultivated soil. Soil fumigation was used to investigate the significance of biological factors in causing poor early growth. In the absence of fumigation, the dry weight per plant 98 days after sowing for the direct-drill treatments was approximately a third of the conventional treatment. The fumigation treatment was effective in completely eliminating the poor early growth observed in the direct-drilled soils. No significant reduction in shoot growth was detected as a consequence of the compaction treatment, despite a reduction in root growth to the level detected in the nil fallow. The results suggest that poor early growth was caused by micro-organisms present in the direct-drilled soils.
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10

Gleason, Sean M., Jennifer Read, and Adrian Ares. "Biomass allocation and phosphorus economics of rain-forest seedlings: effects of fertilization and radiation on soil specialists and soil generalists." Journal of Tropical Ecology 27, no. 2 (February 1, 2011): 147–61. http://dx.doi.org/10.1017/s0266467410000660.

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Abstract:Concurrent nutrient and radiation limitation in forests may engender trade-offs between P-use and radiation-use efficiency in tree species. To quantify these trade-offs, structural and physiological traits were examined among five rain-forest species subjected to four levels of fertilization and two levels of radiation in a glasshouse experiment. Schist specialists,Cryptocarya lividulaandCeratopetalum virchowii, occur only on P-poor schist soils, whereas soil generalists,Cryptocarya mackinnoniana,Franciscodendron laurifoliumandMyristica insipida, occur on both P-poor schist and P-rich basalt soils. Wild seedlings less than 20 cm tall and 1 y old were collected from field sites, treated with fungicide, sorted into treatments (48 plants per species), and grown for 11 mo. We hypothesized that soil specialists would possess mainly non-plastic traits conferring high P-use efficiency, whereas soil generalists would possess markedly plastic traits conferring high radiation capture and use, enabling them to outcompete specialists on P-rich soils. Only generalistC. mackinnonianaand specialistC. virchowiisupported these hypotheses.Cryptocarya mackinnonianahad more plastic root mass fraction, leaf area ratio, P uptake, and higher C assimilation thanC. virchowii, which resulted in greater relative growth rates in high P treatments, but lower P-use efficiency in low P treatments. In contrast, specialistC. lividulademonstrated similar trait plasticity asC. mackinnoniana, suggesting that plasticity in these traits may be poor indicators of fitness on P-poor soils.
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Більше джерел

Дисертації з теми "Poor soil"

1

Rwehumbiza, Filbert. "The effect of seed and soil physical conditions on establishment of sorghum." Thesis, University of Aberdeen, 1994. http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU538899.

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Анотація:
The studies reported here, used sorghum to: (i) investigate the effect of changes in the matric suction (m) of filter-paper on germination and water uptake (ii) assess the effect of seed vigour on seedling response to the m of filter paper and to soil mechanical impedance, (iii) investigate the effect of root-shoot interaction on establishment of seedlings subjected to mechanical impedance (MI), and (iv) evaluate the effects of different amounts of planting rain on crop establishment. A technique for controlling matric suction on seed test paper is described and used to study seed germination at m of 0.1, 1 and 10 kPa. Time to 50% germination was increased, and final lengths of both radicles and cleoptiles reduced by an increase in m from either 0.1 to 1, or 1 to 10 kPa. A link between filter paper m, seed-liquid contact area, seed size, the rate of water uptake and germination is discussed. Unimpeded, pregerminated low vigour and fresh seeds produced a similar root and shoot length, fresh mass, and number of leaves and lateral roots. When grown in compacted soil, low vigour seed took longer to emerge but only when seeds were severely aged. (i) Impedance to the shoot delayed emergence, more so when the root was also impeded. (ii) Shoots emerging through a mechanically impeding layer, had greater extension rates after emergence than unimpeded ones. (iii) Mesocotyls became thicker only when the root systems were impeded. (iv) Impeding the shoot system, increased root extension rate. (v) The length of the first internode, the number of leaves and the spacing of lateral roots were not changed by any of the treatments. Germination was >95% in sand columns watered with 5, 10 or 15 mm equivalents of rain. However, seedling emergence was <15% in the 5 mm compared to 77-100% in the 10 and 15 mm treatments. At harvest (9 DAP), all seedlings in the 5 mm treatment were dead. Seedlings given 10 mm rain showed signs of water stress. The interaction between seed vigour, the amount of water available to germinating seed, and soil mechanical impedance and their effect on crop establishment is discussed.
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2

Saidin, Fadzilah. "Behavior of geosynthetic reinforced soil walls with poor quality backfills on yielding foundations /." Thesis, Connect to this title online; UW restricted, 2007. http://hdl.handle.net/1773/10124.

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3

Donaldson, Jason. "Are forests restricted by nutrient poor soils? : an analysis of soil nutrient stocks and associated vegetation in the fynbos biome, South Africa." Bachelor's thesis, University of Cape Town, 2011. http://hdl.handle.net/11427/26584.

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The realized woody biomass of the Fynbos Biome in the Western Cape, South Africa falls below the climatic potential to support woody biomass. The lack of substantial tracts of woody forests has long puzzled ecologists, although patchy nutrient distribution and fire disturbance are thought to play a role. The issue has been confounded in the recent past by the invasion of non-indigenous woody plants into formerly low stature fynbos dominated areas. Despite low wood nutrient concentrations, a substantial proportion of nutrients are locked up in the wood of forests due to the large volume of wood. Nevertheless, nutrient stock analysis indicated that plant available nutrients in the poorest global soils (including fynbos soils) are sufficient to support forests (indigenous and alien). I hypothesized that soil nutrient stocks of the Fynbos Biome are sufficient in quantity to support closed canopy indigenous forests with a woody biomass greater than 225 000 kg ha⁻¹ and that alien Pinus spp. and Eucalyptus spp. have lower nutrient stocks than indigenous fynbos species. The study was conducted in the Orange Kloof Forest Reserve and Jonkershoek Nature Reserve within the Western Cape (South Africa). Soil, wood and leaf samples of representative species were collected from indigenous forest, fynbos, E. globulus and P. halepensis and assessed for nutrient contents. Estimates of potential woody biomass on four different soils indicated that indigenous forests would be limited by fynbos soil stocks to below the 225 000 kg ha⁻¹. Pine forest had lower wood nutrient concentrations (mg kg⁻¹, n=6) for N (2466), K (2433), Ca (383), and Fe (34) than indigenous forest species (n=11) N (3427), K (4254), Ca (1636) and Fe (140). The low nutrient stocks in pine wood may allow them to grow tall and be competitive in the shrubby fynbos biome where indigenous forests are limited by expensive wood costs.
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4

CAMELIN, ENRICO. "Waste meets poor soils: perspectives on sewage sludge recycling." Doctoral thesis, Politecnico di Torino, 2020. http://hdl.handle.net/11583/2842501.

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5

Turkoglu, Melih. "Two-dimensional Numerical Analysis Of Tunnel Collapse Driven In Poor Ground Conditions." Master's thesis, METU, 2013. http://etd.lib.metu.edu.tr/upload/12615456/index.pdf.

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Insufficient information on the host medium can cause serious problems, even collapse, during construction in a tunnel. This study focuses on understanding the reasons behind the collapse of the Tunnel BT24 to be opened within the framework of Ankara-Istanbul High Speed Railway Project. The tunnel is located near Bozü
yü
k in the Bilecik Province. The collapsed section of the tunnel was driven into a highly weathered, weak to medium rock mass. Unanticipated geological/geotechnical circumstances caused excessive deformations at the section on which the primary support system was applied, leading eventually to collapse. To understand the response of the tunnel and the collapse mechanism, the construction sequence is simulated using two-dimensional plane-strain and axisymmetric finite element models. The analyses were carried out for the section with and without invert closure of the shotcrete liner. To implement the effects of likely unfavorable ground conditions on the tunnel response, a number of fault scenarios and possible creep effects were also considered with those two alternatives. Displacements in the tunnel periphery, forces and moments in the primary liner as well as the plastic deformation zones in the surrounding ground were determined for each case and comprasions were made accordingly. It is concluded that the unforseen ground circumstances might have substantially aggravated the deformations in the section and that the lack of ring closure of the primary liner at invert played the key role in the collapse.
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6

Osorio, Leyton Javier Mauricio. "Assessment of SWAT to Enable Development of Watershed Management Plans for Agricultural Dominated Systems under Data-Poor Conditions." Diss., Virginia Tech, 2012. http://hdl.handle.net/10919/27747.

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Modeling is an important tool in watershed management. In much of the world, data needed for modeling, both for model inputs and for model evaluation, are very limited or non-existent. The overall objective of this research was to enable development of watershed management plans for agricultural dominated systems under situations where data are scarce. First, uncertainty of the SWAT modelâ s outputs due to input parameters, specifically soils and high resolution digital elevation models, which are likely to be lacking in data-poor environments, was quantified using Monte Carlo simulation. Two sources of soil parameter values (SSURGO and STATSGO) were investigated, as well as three levels of DEM resolution (10, 30, and 90 m). Uncertainty increased as the input data became coarser for individual soil parameters. The combination of SSURGO and the 30 m DEM proved to adequately balance the level of uncertainty and the quality of input datasets. Second, methods were developed to generate appropriate soils information and DEM resolution for data-poor environments. The soils map was generated based on lithology and slope class, while the soil attributes were generated by linking surface soil texture to soils characterized in the SWAT soils database. A 30 m resolution DEM was generated by resampling a 90 m DEM, the resolution that is readily available around the world, by direct projection using a cubic convolution method. The effect of the generated DEM and soils data on model predictions was evaluated in a data-rich environment. When all soil parameters were varied at the same time, predictions based on the derived soil map were comparable to the predictions based on the SSURGO map. Finally, the methodology was tested in a data-poor watershed in Bolivia. The proposed methodologies for generating input data showed how available knowledge can be employed to generate data for modeling purposes and give the opportunity to incorporate uncertainty in the decision making process in data-poor environments.
Ph. D.
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7

Abou, El Goud Amal Karam Sayed Ahmed. "Effect of endomycorrhizal fungi and compost on the yield and quality of maize and sunflower plants in poor nutrients soil." Kassel Kassel Univ. Press, 2010. http://d-nb.info/1003132960/04.

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8

Abou, El Goud Amal Karam Sayed Ahmed [Verfasser]. "Effect of Endomycorrhizal Fungi and Compost on the Yield and Quality of Maize and Sunflower Plants in Poor Nutrients Soil / Amal Karam Sayed Abou El-Goud." Kassel : Kassel University Press, 2010. http://d-nb.info/1016840985/34.

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9

Wadgaonkar, Shrutika. "Nouveaux procédés de bioremédiation pour le traitement des sols et des sédiments sélénifères." Thesis, Paris Est, 2017. http://www.theses.fr/2017PESC1105.

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L'objectif de cette thèse a été de développer une technologie pour l'assainissement des sols / sédiments sélénifères et d’étudier la réduction microbienne des oxy-anions de sélénium dans différentes conditions de respiration et de configurations du bioréacteur.Le sol sélénifère prélevé, dans les terres agricoles cultivées de blé au Pendjab (Inde), a été caractérisé et son lavage a été optimisé en faisant varier les paramètres tels que le temps de réaction, la température, le pH et le rapport liquide / solide. Afin de maximiser l'élimination et la récupération du sélénium à partir de ce sol, l'effet des ions compétiteurs et les composés oxydants comme les agents d'extraction pour le lavage du sol, ont également été étudiés. Bien que les agents oxydants aient montré une efficacité maximale d'élimination du sélénium (39%), la présence d'agents oxydants dans le lixiviat et le sol agricole peut augmenter le coût de leur post-traitement. Les plantes aquatiques, Lemma minor et Egeria densa ont été utilisées pour étudier la phyto-remédiation du lixiviat du sol contenant des agents oxydants. Cependant, l'efficacité d'élimination du sélénium par les plantes aquatiques a été significativement affectée par les fortes concentrations de ces agents oxydants dans le lixiviat du sol.Le rinçage du sol sélénifère a révélé un motif de migration du sélénium à travers la colonne du sol. La migration de la fraction de sélénium soluble de la couche supérieure vers la couche inférieure et sa réduction et son accumulation subséquentes dans les couches inférieures de la colonne de sol, ont été observées pendant le rinçage du sol. L'efficacité d'élimination du sélénium par la méthode de rinçage du sol a diminué avec une augmentation de la hauteur de la colonne. De plus, le lixiviat contenant des oxy-anions de sélénium obtenus à partir du lavage du sol, a été traité dans un réacteur UASB en faisant varier l'alimentation organique. Des effluents contenant moins de 5 μg de sélénium L-1 ont été obtenus, ce qui est conforme aux normes de l'USEPA pour la limite de rejet de sélénium dans les eaux usées.De plus, la bio-remédiation ex situ des oxy-anions de sélénium a été étudiée dans des conditions variables. Une bactérie aérobie (Delftia lacustris) capable de transformer le sélénate et le sélénite en sélénium élémentaire, mais aussi en composés d'ester de sélénium solubles jusque-là inconnus, a été isolée et caractérisée de manière fortuite. Alternativement, la bio-réduction anaérobie du sélénate couplé au méthane en tant que donneur d'électrons, a été étudiée dans des bouteilles de sérum et un filtre percolateur en utilisant des sédiments marins comme inoculum. Enfin, l'effet de la contamination d'autres oxy-anions chalcogènes, en plus du sélénium, a été étudié. La réduction simultanée de la sélénite et de la tellurite par un consortium microbien mixte ainsi que la rétention des nanostructures de Se et de Te biogènes dans l'EPS, ont été réalisées durant une opération de 120 jours dans un bioréacteur UASB
The aim of this Ph.D. was to develop a technology for the remediation of seleniferous soils/sediments and to explore microbial reduction of selenium oxyanions under different respiration conditions and bioreactor configurations.Seleniferous soil collected from the wheat-grown agricultural land in Punjab (India) was characterized and its soil washing was optimized by varying parameters such as reaction time, temperature, pH and liquid to solid ratio. In order to maximize selenium removal and recovery from this soil, effect of competing ions and oxidizing agents as chemical extractants for soil washing were also studied. Although oxidizing agents showed a maximum selenium removal efficiency (39%), the presence of oxidizing agents in the leachate and the agricultural soil may increase the cost of their post-treatment. Aquatic plants, Lemma minor and Egeria densa were used to study phytoremediation of the soil leachate containing oxidizing agents. However, the selenium removal efficiency by aquatic weeds was significantly affected by the high concentrations of these oxidizing agents in the soil leachate.Seleniferous soil flushing revealed the selenium migration pattern across the soil column. Migration of soluble selenium fraction from the upper to the lower layers and its subsequent reduction and accumulation in the lower layers of the soil column was observed during soil flushing. The selenium removal efficiency by the soil flushing method decreased with an increase in the column height. Furthermore, the soil leachate containing selenium oxyanions obtained from soil washing was treated in a UASB reactor by varying the organic feed. Effluent containing less than 5 μg L-1 selenium was achieved, which is in accordance with the USEPA guidelines for selenium wastewater discharge limit.Moreover, ex situ bioremediation of selenium oxyanions was studied under variable conditions. An aerobic bacterium (Delftia lacustris) capable of transforming selenate and selenite to elemental selenium, but also to hitherto unknown soluble selenium ester compounds was serendipitously isolated and characterized. Alternatively, anaerobic bioreduction of selenate coupled to methane as electron donor was investigated in serum bottles and a biotrickling filter using marine sediment as inoculum. Finally, the effect of contamination of other chalcogen oxyanions in addition to selenium was studied. Simultaneous reduction of selenite and tellurite by a mixed microbial consortium along with the retention of biogenic Se and Te nanostructures in the EPS was achieved during a 120-day UASB bioreactor operation
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Rodriguez, Tiago Garcia. "Caracterização geotécnica de um solo de diabásio por meio de ensaios SPT e CPT." [s.n.], 2013. http://repositorio.unicamp.br/jspui/handle/REPOSIP/258775.

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Orientador: Paulo José Rocha de Albuquerque
Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Civil, Arquitetura e Urbanismo
Made available in DSpace on 2018-08-22T13:59:44Z (GMT). No. of bitstreams: 1 Rodriguez_TiagoGarcia_M.pdf: 30504906 bytes, checksum: c4b35d11f7756b790472830322bab920 (MD5) Previous issue date: 2013
Resumo: A presente dissertação tem por objetivo apresentar a caracterização geotécnica do solo de diabásio do Campo Experimental da Faculdade de Engenharia Civil da Unicamp, por meio de ensaios de campo SPT e CPT. Verificar a adequabilidade dos ensaios as condições do solo tropical, lateritico, típico da região de Campinas, por meio de proposicoes de classificação de comportamento de solos e da estimativa de parâmetros geotécnicos, assim como as possíveis correlações, teóricas e empíricas, entre os dois ensaios. Foram utilizados ensaios de cone, mecânico e elétrico, e ensaios SPT com medição de energia. As propostas para classificações dos tipos de solo, através do CPT, utilizadas indicaram duas camadas distintas a primeira de solos de comportamento arenosos a silto-arenosos e a segunda de solos de comportamento siltosos a siltoargilosos, em concordância com a classificação obtida em laboratório. As proposicoes utilizadas para estimativa de parâmetros geotécnicos tiveram que ser ajustadas para o solo do campo experimental. A correlação (qc/pa)/N60 obtida foi de 4 para o solos coluvionar (areno-siltoso) e 2,5 para o solo residual (siltoso) em concordância com os valores encontrados na literatura
Abstract: The purpose of this dissertation is to present the geotechnical characterization of the diabasic soil of the Experimental Field of the Unicamp School of Civil Engineering by means of SPT and CPT field trials, and to check the adequacy of such trials to the conditions of the tropical, lateritic soil, which is typical of the Campinas region by means of propositions to classify the behavior of the soils and estimation of geotechnical parameters, as well as possible theoretical and empirical correlations between the two trials. Cone, mechanical and electrical trials were used as well as SPT trials with measurement of energy. The proposals used to classify the types of soil via CPT indicated two separate layers: the first one with soils with sandy to silty-sandy behavior, and the second layer of soils with silty to silty-clayey behavior, in agreement with the laboratory classification. The propositions used to estimate the geotechnical parameters had to be adjusted to the soil of the experimental field. The correlation (qc/pa)/N60 obtained was 4 for colluvial soil (sandy-silty), and 2.5 for residual soil (silty) in agreement with the values found in the literature
Mestrado
Geotecnia
Mestre em Engenharia Civil
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Книги з теми "Poor soil"

1

Roy, B. C. Subsidising food crisis: Synthetic fertilisers lead to poor soil and less food. Bangalore: Greenpeace India, 2012.

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Dr, Place Frank, ed. The impact of agroforestry-based soil fertility replenishment practices on the poor in western Kenya. Washington, D.C: International Food Policy Research Institute, 2005.

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Madulu, N. F. Contraception prevalence under rural poverty: The case of the rural areas of Kondoa District, Tanzania. Stockholm: Stockholm University, School of Geography, Dept. of Human Geography [and] Dept. of Physical Geography, 1995.

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Elahi, K. Maudood. Riverbank erosion, flood, and population displacement in Bangladesh: A report on the Riverbank Erosion Impact Study. Dhaka, Bangladesh: Riverbank Erosion Impact Study, Jahangirnagar University, 1990.

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5

Jacques, Varet, ed. Le Sol: Interface dans l'environnement : ressource pour le développement. Paris: Masson, 1996.

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Elahi, K. Maudood. Riberbank erosion, flood, and population displacement in Bangladesh: A report on the Riverbank Erosion Impact Study. Dhaka, Bangladesh: Riverbank Erosion Impact Study, Jahangirnagar University, 1990.

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7

Mayer, Cassie. Soil. Oxford: Heinemann Library, 2008.

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Mayer, Cassie. Soil. Oxford: Heinemann Library, 2009.

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9

Nicole, Ballenger, Wiebe Keith Daniel 1962-, Pinstrup-Andersen Per, and International Food Policy Research Institute., eds. Who will be fed in the 21st century?: Challenges for science and policy. Washington, D.C: International Food Policy Research Institute, 2001.

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10

Frédéric, Thomas, ed. Les sols agricoles: Comprendre, observer, diagnostiquer. Paris: Éditions France Agricole, 2016.

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Частини книг з теми "Poor soil"

1

Jeffrey, David W. "Australian heathlands and other nutrient-poor terrestrial ecosystems." In Soil~Plant Relationships, 211–23. Dordrecht: Springer Netherlands, 1987. http://dx.doi.org/10.1007/978-94-011-6076-6_16.

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2

Kleinert, A., V. A. Benedito, R. J. L. Morcillo, J. Dames, P. Cornejo-Rivas, A. Zuniga-Feest, Mabel Delgado, and Gastón Muñoz. "Morphological and Symbiotic Root Modifications for Mineral Acquisition from Nutrient-Poor Soils." In Soil Biology, 85–142. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-75910-4_4.

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Martin, Claude. "A Diversity of Plant Life on Poor Soil." In The Rainforests of West Africa, 66–89. Basel: Birkhäuser Basel, 1991. http://dx.doi.org/10.1007/978-3-0348-7726-8_4.

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4

Stigter, C. J. Kees. "Rural Response to Climate Change in Poor Countries." In Sustaining Soil Productivity in Response to Global Climate Change, 67–77. Oxford, UK: Wiley-Blackwell, 2011. http://dx.doi.org/10.1002/9780470960257.ch5.

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5

Hinsinger, Philippe, Michael J. Bell, John L. Kovar, and Philip J. White. "Rhizosphere Processes and Root Traits Determining the Acquisition of Soil Potassium." In Improving Potassium Recommendations for Agricultural Crops, 99–117. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-59197-7_4.

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AbstractPlants acquire K+ ions from the soil solution, and this small and dynamic pool needs to be quickly replenished via desorption of surface-adsorbed K from clay minerals and organic matter, by release of interlayer K from micaceous clay minerals and micas, or structural K from feldspars. Because of these chemical interactions with soil solid phases, solution K+ concentration is kept low and its mobility is restricted. In response, plants have evolved efficient strategies of root foraging. Root traits related to root system architecture (root angle and branching), root length and growth, together with root hairs and mycorrhiza-related traits help to determine the capacity of plants to cope with the poor mobility of soil K. Rooting depth is also important, given the potentially significant contribution of subsoil K in many soils. Root-induced depletion of K+ shifts the exchange equilibria, enhancing desorption of K, as well as the release of nonexchangeable, interlayer K from minerals in the rhizosphere. Both these pools can be bioavailable if plant roots can take up significant amounts of K at low concentrations in the soil solution (in the micromolar range). In addition, roots can significantly acidify their environment or release large amounts of organic compounds (exudates). These two processes ultimately promote the dissolution of micas and feldspars in the rhizosphere, contributing to the mining strategy evolved by plants. There are thus several root or rhizosphere-related traits (morphological, physiological, or biochemical) that determine the acquisition of K by crop species and genotypes.
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6

Rode, M. W. "Aboveground nutrient cycling and forest development on poor sandy soil." In Nutrient Uptake and Cycling in Forest Ecosystems, 337–43. Dordrecht: Springer Netherlands, 1995. http://dx.doi.org/10.1007/978-94-011-0455-5_39.

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7

Berendse, Frank. "Effects of dominant plant species on soils during succession in nutrient-poor ecosystems." In Plant-induced soil changes: Processes and feedbacks, 73–88. Dordrecht: Springer Netherlands, 1998. http://dx.doi.org/10.1007/978-94-017-2691-7_4.

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8

Nenadic, Nedeljko. "Effect of fertilization on soybean yield and quality on poor soil." In Plant Nutrition for Sustainable Food Production and Environment, 709–10. Dordrecht: Springer Netherlands, 1997. http://dx.doi.org/10.1007/978-94-009-0047-9_226.

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9

Swarup, Anand. "Sustainable Management of Salt-Affected Soils and Poor-Quality Ground Waters for Enhancing Crop Production." In Developments in Soil Salinity Assessment and Reclamation, 327–34. Dordrecht: Springer Netherlands, 2012. http://dx.doi.org/10.1007/978-94-007-5684-7_21.

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Minhas, P. S., and J. C. Dagar. "Use of Tree Plantations in Water-table Drawdown and Combating Soil Salinity." In Agroforestry for the Management of Waterlogged Saline Soils and Poor-Quality Waters, 33–48. New Delhi: Springer India, 2016. http://dx.doi.org/10.1007/978-81-322-2659-8_3.

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Тези доповідей конференцій з теми "Poor soil"

1

Barnette, Ethan R., Charles V. Privette, Calvin B. Sawyer, and Dara M. Park. "Optimizing Grass Establishment to Stabilize Poor Soils." In Soil Erosion Research Under a Changing Climate, January 8-13, 2023, Aguadilla, Puerto Rico, USA. St. Joseph, MI: American Society of Agricultural and Biological Engineers, 2023. http://dx.doi.org/10.13031/soil.23027.

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Barnette, Ethan R., Charles V. Privette, Calvin B. Sawyer, and Dara M. Park. "Optimizing Grass Establishment to Stabilize Poor Soils." In Soil Erosion Research Under a Changing Climate, January 8-13, 2023, Aguadilla, Puerto Rico, USA. St. Joseph, MI: American Society of Agricultural and Biological Engineers, 2023. http://dx.doi.org/10.13031/soil.2023027.

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Mohamed, Wael, and Per-Erik Austrell. "OPTIMIZATION OF WIND TURBINE FOUNDATIONS FOR POOR SOIL." In 5th International Conference on Computational Methods in Structural Dynamics and Earthquake Engineering Methods in Structural Dynamics and Earthquake Engineering. Athens: Institute of Structural Analysis and Antiseismic Research School of Civil Engineering National Technical University of Athens (NTUA) Greece, 2015. http://dx.doi.org/10.7712/120115.3696.885.

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Anwar, Jafri Sayyad, and Sharma Ujjwal. "To study the geotextile reinforced soil for poor sub-grade." In INTERNATIONAL CONFERENCE ON SUSTAINABLE INNOVATION IN MECHANICAL ENGINEERING. AIP Publishing, 2022. http://dx.doi.org/10.1063/5.0079942.

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"Stabilization of Black Cotton Soil with Groundnut Shell Ash." In Recent Advancements in Geotechnical Engineering. Materials Research Forum LLC, 2021. http://dx.doi.org/10.21741/9781644901618-6.

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Abstract. The analysis of GSA for the stabilization of soil samples is the subject of this research paper. In recent years, soil stabilization techniques have been effective in improving the shear strength parameters of poor soils. GSA is a naturally occurring substance that causes human health and environmental issues. Physical properties of soil were calculated, including Atterberg's limits, compaction characteristics, and strength characteristics of virgin soil samples. GSA was applied to the soil in various percentages (2 to 10 percent). The soil sample's intensity increased up to 6% before decreasing. It is clear that 6% of GSA to the soil is an optimum percentage and it leads to an increase in shear strength and bearing capacity in expansive soil.
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Card, Robert J., and Brent Keil. "Steel Pipe Installation in Poor Soil Conditions: A Determination of Optimum Trench Width." In Pipelines 2017. Reston, VA: American Society of Civil Engineers, 2017. http://dx.doi.org/10.1061/9780784480878.033.

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"Use of Carbon Geomembrane for Foundations of Buildings in Poor Load-Bearing Foundation Soil." In Universal Researchers. Universal Researchers, 2015. http://dx.doi.org/10.17758/ur.u0315333.

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Asadi, Hossein, Behzad Ghadimi, and Hamid Nikraz. "An Operational Solution to Overcome the Very Poor Subgrade Soil Condition of the Azadegan Freeway." In Research, Development and Practice in Structural Engineering and Construction. Singapore: Research Publishing Services, 2012. http://dx.doi.org/10.3850/978-981-08-7920-4_gfe-19-0453.

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9

Javier M Osorio Leyton, Mary Leigh Wolfe, Conrad D Heatwole, Christopher W Zobel, and Darrell J Bosch. "Assessment of SWAT Model Uncertainty of Soil Parameters for Agricultural Dominated Systems under Data-Poor Conditions." In 2012 Dallas, Texas, July 29 - August 1, 2012. St. Joseph, MI: American Society of Agricultural and Biological Engineers, 2012. http://dx.doi.org/10.13031/2013.41798.

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10

Si, Jinzhao, Shuangcheng Zhang, and Yufen Niu. "PS-InSAR and UAV technology used in the stability study of Ankang expansive soil airport." In 5th Joint International Symposium on Deformation Monitoring. Valencia: Editorial de la Universitat Politècnica de València, 2022. http://dx.doi.org/10.4995/jisdm2022.2022.13869.

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Expansive soil is a natural geological body with obvious expansion and contraction, multiple fissures and other undesirable properties. The deformation monitoring of expansive soil in high-fill areas under the combined action of wet expansion and dry contraction has become a hotspot of related research. to large-scale soil disasters. Time-series Interferometric Synthetic Aperture Radar (InSAR) technology is widely used in the monitoring of various geological hazards due to its advantages of wide coverage, high monitoring accuracy, and all-weather operation. This study takes Ankang Airport (AKA) expansive soil airport as an example. First, the ground digital elevation model (DEM) of the airport filling area was obtained by using UAV; secondly, the deformation rate and deformation time series of the expansive soil airport were obtained by using the persistent scatterer InSAR (PS-InSAR) technology; third, for the coherence In poor areas, artificial corner reflectors (CR) are arranged to increase stable scattering points; Finally, the deformation time series of feature points are extracted, combined with regional precipitation data analysis, the relationship between the periodic deformation of the airport expansive soil slope and rainfall. There is a subsidence trend along the LOS direction in the dry season, which is consistent with the expansion and contraction characteristics of expansive soils. Finally, the deformation rate is proportional to the depth of the expansive soil fill. It is judged that the existing small surface deformation and its periodic deformation distribution are caused by the combined action of the settlement after construction of the expansive soil filling area and the expansion and contraction characteristics of the expansive soil.
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Звіти організацій з теми "Poor soil"

1

Research Institute (IFPRI), International Food Policy. The impact of agroforestry-based soil fertility replenishment practices on the poor in Western Kenya Report. Washington, DC: International Food Policy Research Institute, 2005. http://dx.doi.org/10.2499/0896291448rr142.

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2

Graber, Ellen R., Linda S. Lee, and M. Borisover. An Inquiry into the Phenomenon of Enhanced Transport of Pesticides Caused by Effluents. United States Department of Agriculture, July 1995. http://dx.doi.org/10.32747/1995.7570559.bard.

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The objective of this collaborative research project was to determine the factors that may cause enhanced pesticide transport under effluent irrigation. For s-triazines, the potential for enhanced transport through association with effluent dissolved organic matter (OM) was shown to be small in batch and column studies and in numerical simulations. High alkalinity and pH of treated effluents increased soil-solution pH for selected soil-effluent combinations, promoting the dissolution of soil OM and mobilizing otherwise OM-retained pesticides. Evapotranspiration in column studies resulted in increased pore-water concentrations of dissolved OM and some pesticide transport enhancement with the greatest effect observed with OM-poor soils. For ionogenic pesticides, effluent-induced increases in soil-solution pH increased the mobility of pesticides with acid dissociation constants within 2 pH units of the initial soil-solution pH. Effluents high in suspended solids and/or monovalent cations resulted in blockage of soil pores reducing water-flow velocity and/or changing flow paths. Reduced flow resulted in an increase in desorption time of soil sorbed pesticides, increasing the amount available for further transport with the net effect being soil texture dependent. In terms of pesticide degradation in soils, effluents appeared to have only a minor effect for the few pesticides investigated.
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Chefetz, Benny, and Jon Chorover. Sorption and Mobility of Pharmaceutical Compounds in Soils Irrigated with Treated Wastewater. United States Department of Agriculture, 2006. http://dx.doi.org/10.32747/2006.7592117.bard.

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Research into the fate of pharmaceutical compounds (PCs) in the environment has focused on aspects of removal efficiency during sewage treatment, degradation in surface water and accumulation in soils and sediments. However, very little information is available on the binding interactions of pharmaceuticals with dissolved organic matter (DOM) originating from wastewater treatment. Such interactions can significantly affect the transport potential of PCs in soils by altering compound affinity for soil particle surfaces. Our primary hypothesis is that the transport potential of PCs in soils is strongly impacted by the type and strength of interaction with DOM and the stability of resulting DOM-PC complexes. The overarching goal of the proposed work is to develop a better understanding of the risk associated with introduction of PCs into the environment with treated wastewater. This goal has been achieved by elucidating the mechanisms of the interaction of selected pharmaceuticals (that have shown to be widespread wastewater contaminants) with DOM constituents; by determining the stability and fate of DOM-PC complexes introduced to soils and soil constituents; and by evaluating the potential uptake of these compounds by plants. Based on the results obtained in this study (column and batch sorption-desorption experiments), we suggest that PCs can be classified as slow-mobile compounds in SOM-rich soil layers. When these compounds pass this layer and/or are introduced into SOM-poor soils, their mobility increases significantly. Our data suggest that in semiarid soils (consisting of low SOM), PCs can potentially be transported to the groundwater in fields irrigated with reclaimed wastewater. Moreover, the higher mobility of the acid PCs (i.e., naproxen and diclofenac) in freshwater column systems suggests that their residues in soils irrigated with reclaimed wastewater can leach from the root zone and be transported to the groundwater after rain events. Our data obtained from the binding experiments of PCs with DOM demonstrate that the hydrophobic DOM fractions were more efficient at sorbing PCs than the more polar hydrophilic fractions at a pH near the pKa of the analytes. At the pH of natural semiarid water and soil systems, including that of reclaimed wastewater and biosolids, the role of the hydrophobic fractions as sorption domains is less important than the contribution of the hydrophilic fractions. We also hypothesize that the DOM fractions interact with each other at the molecular level and do not act as independent sorption domains. In summary, our data collected in the BARD project demonstrate that the sorption abilities of the DOM fractions can also significantly affect the mobility of pharmaceutical compounds in soils influenced by intensive irrigation with treated wastewater or amended with biosolids.
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Chefetz, Benny, and Jon Chorover. Sorption and Mobility of Pharmaceutical Compounds in Soils Irrigated with Treated Wastewater. United States Department of Agriculture, 2006. http://dx.doi.org/10.32747/2006.7709883.bard.

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Research into the fate of pharmaceutical compounds (PCs) in the environment has focused on aspects of removal efficiency during sewage treatment, degradation in surface water and accumulation in soils and sediments. However, very little information is available on the binding interactions of pharmaceuticals with dissolved organic matter (DOM) originating from wastewater treatment. Such interactions can significantly affect the transport potential of PCs in soils by altering compound affinity for soil particle surfaces. Our primary hypothesis is that the transport potential of PCs in soils is strongly impacted by the type and strength of interaction with DOM and the stability of resulting DOM-PC complexes. The overarching goal of the proposed work is to develop a better understanding of the risk associated with introduction of PCs into the environment with treated wastewater. This goal has been achieved by elucidating the mechanisms of the interaction of selected pharmaceuticals (that have shown to be widespread wastewater contaminants) with DOM constituents; by determining the stability and fate of DOM-PC complexes introduced to soils and soil constituents; and by evaluating the potential uptake of these compounds by plants. Based on the results obtained in this study (column and batch sorption-desorption experiments), we suggest that PCs can be classified as slow-mobile compounds in SOM-rich soil layers. When these compounds pass this layer and/or are introduced into SOM-poor soils, their mobility increases significantly. Our data suggest that in semiarid soils (consisting of low SOM), PCs can potentially be transported to the groundwater in fields irrigated with reclaimed wastewater. Moreover, the higher mobility of the acid PCs (i.e., naproxen and diclofenac) in freshwater column systems suggests that their residues in soils irrigated with reclaimed wastewater can leach from the root zone and be transported to the groundwater after rain events. Our data obtained from the binding experiments of PCs with DOM demonstrate that the hydrophobic DOM fractions were more efficient at sorbing PCs than the more polar hydrophilic fractions at a pH near the pKa of the analytes. At the pH of natural semiarid water and soil systems, including that of reclaimed wastewater and biosolids, the role of the hydrophobic fractions as sorption domains is less important than the contribution of the hydrophilic fractions. We also hypothesize that the DOM fractions interact with each other at the molecular level and do not act as independent sorption domains. In summary, our data collected in the BARD project demonstrate that the sorption abilities of the DOM fractions can also significantly affect the mobility of pharmaceutical compounds in soils influenced by intensive irrigation with treated wastewater or amended with biosolids.
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5

Shmulevich, Itzhak, Shrini Upadhyaya, Dror Rubinstein, Zvika Asaf, and Jeffrey P. Mitchell. Developing Simulation Tool for the Prediction of Cohesive Behavior Agricultural Materials Using Discrete Element Modeling. United States Department of Agriculture, October 2011. http://dx.doi.org/10.32747/2011.7697108.bard.

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The underlying similarity between soils, grains, fertilizers, concentrated animal feed, pellets, and mixtures is that they are all granular materials used in agriculture. Modeling such materials is a complex process due to the spatial variability of such media, the origin of the material (natural or biological), the nonlinearity of these materials, the contact phenomenon and flow that occur at the interface zone and between these granular materials, as well as the dynamic effect of the interaction process. The lack of a tool for studying such materials has limited the understanding of the phenomena relevant to them, which in turn has led to energy loss and poor quality products. The objective of this study was to develop a reliable prediction simulation tool for cohesive agricultural particle materials using Discrete Element Modeling (DEM). The specific objectives of this study were (1) to develop and verify a 3D cohesionless agricultural soil-tillage tool interaction model that enables the prediction of displacement and flow in the soil media, as well as forces acting on various tillage tools, using the discrete element method; (2) to develop a micro model for the DEM formulation by creating a cohesive contact model based on liquid bridge forces for various agriculture materials; (3) to extend the model to include both plastic and cohesive behavior of various materials, such as grain and soil structures (e.g., compaction level), textures (e.g., clay, loam, several grains), and moisture contents; (4) to develop a method to obtain the parameters for the cohesion contact model to represent specific materials. A DEM model was developed that can represent both plastic and cohesive behavior of soil. Soil cohesive behavior was achieved by considering tensile force between elements. The developed DEM model well represented the effect of wedge shape on soil behavior and reaction force. Laboratory test results showed that wedge penetration resistance in highly compacted soil was two times greater than that in low compacted soil, whereas DEM simulation with parameters obtained from the test of low compacted soil could not simply be extended to that of high compacted soil. The modified model took into account soil failure strength that could be changed with soil compaction. A three dimensional representation composed of normal displacement, shear failure strength and tensile failure strength was proposed to design mechanical properties between elements. The model based on the liquid bridge theory. An inter particle tension force measurement tool was developed and calibrated A comprehensive study of the parameters of the contact model for the DEM taking into account the cohesive/water-bridge was performed on various agricultural grains using this measurement tool. The modified DEM model was compared and validated against the test results. With the newly developed model and procedure for determination of DEM parameters, we could reproduce the high compacted soil behavior and reaction forces both qualitatively and quantitatively for the soil conditions and wedge shapes used in this study. Moreover, the effect of wedge shape on soil behavior and reaction force was well represented with the same parameters. During the research we made use of the commercial PFC3D to analyze soil tillage implements. An investigation was made of three different head drillers. A comparison of three commonly used soil tillage systems was completed, such as moldboard plow, disc plow and chisel plow. It can be concluded that the soil condition after plowing by the specific implement can be predicted by the DEM model. The chisel plow is the most economic tool for increasing soil porosity. The moldboard is the best tool for soil manipulation. It can be concluded that the discrete element simulation can be used as a reliable engineering tool for soil-implement interaction quantitatively and qualitatively.
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6

Behnood, Ali, and Jan Olek. Development of Subgrade Stabilization and Slab Undersealing Solutions for PCC Pavements Restoration and Repairs. Purdue University, 2020. http://dx.doi.org/10.5703/1288284317128.

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The loss of functionality and the development of distress in concrete pavements is often attributable to the poor subbase and subgrade conditions and/or loss of support due to the development of the voids underneath the slab. Subgrade soil stabilization can be used as an effective approach to restore the functionality of the subgrades in patching projects. This research had two main objectives: (1) identifying the best practices for soil stabilization of the existing subgrade during pavement patching operations and (2) identifying and developing new, modified grouting materials for slab stabilization and undersealing. Various stabilization scenarios were tested and showed improved performance of the subgrade layer. The use of geotextile along with aggregate course was found to significantly reduce the settlement. Non-removable flowable fill was also found to significantly reduce the subgrade settlement. Cement-treated aggregate and lean concrete provided the best performance, as they prevented formation of any noticeable settlement in the underlying subgrade.
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7

Савосько, Василь Миколайович, Наталія Вікторівна Товстоляк, Юрій Васильович Лихолат, and Іван Панасович Григорюк. Structure and Diversity of Urban Park Stands at Kryvyi Rih Ore-Mining & Metallurgical District, Central Ukraine. Podgorica, 2020. http://dx.doi.org/10.31812/123456789/3946.

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The present study examines the relationships between structure (floristic composition, dendrometric parameters), diversity (diversity and evenness indexes) of urban forest park stands and the ecological (soil fertility, soil moisture), environmental factors (air pollution). The study is based on the forest park stands inventory data, performed from 2012 to 2017 in Kryvyi Rih City, Central Ukraine. The floristic compositions of the urban forest park stands are poor. There are only 23 species that belong to 14 families and 12 genera. More families were represented by at least more than 2% of taxon diversity. While Ulmaceae (2 genera, 4 species–17,39 %), Fabaceae (3 genera, 2 species–17,39 %), Aсеrасеае (1 genera, 4 species–17,39 %) were the most representative families. It was established that at forest park the values of stand density varied from 490 to 660 trees*ha-1, stem heights were from 26 to 31 m, stem diameters were from 13 to 17 cm, stand basal area were from 32 to 49 m2*ha-1, stand volume were from 200 to 415 m3*ha-1. the values of relative stem heights were from 0,63 to 0,82 m*year-1, relative stem diameters were from 0,31 to 0,43 cm*year-1, relative stand basal area were from 0,80 to 1,19 m2*ha-1*year-1, relative stand volume were from 5,45 to 10,28 m3*ha-1*year-1. The varied values of the forest park stands index (Shannon-Wiener diversity index from 0,75 to 1,61, Pielou‟s evenness index from 0,53 to 0,86, Simpson‟s diversity from 0,24 to 0,60, Margalef‟s diversity index from 0,87 to 6,97) indicate the ecological instability of these woody plant communities. Current state of the urban forest park stands determined by the combined influence of ecological (soil fertility, soil moisture) and environmental factors (air pollution).
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8

Francis, John K. The Nutrient Pool of Five Important Bottomland Hardwood Soils. New Orleans, LA: U.S. Department of Agriculture, Forest Service, Southern Forest Experiment Station, 1988. http://dx.doi.org/10.2737/so-rn-327.

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9

Castellano, Mike J., Abraham G. Shaviv, Raphael Linker, and Matt Liebman. Improving nitrogen availability indicators by emphasizing correlations between gross nitrogen mineralization and the quality and quantity of labile soil organic matter fractions. United States Department of Agriculture, January 2012. http://dx.doi.org/10.32747/2012.7597926.bard.

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A major goal in Israeli and U.S. agroecosystems is to maximize nitrogen availability to crops while minimizing nitrogen losses to air and water resources. This goal has presented a significant challenge to global agronomists and scientists because crops require large inputs of nitrogen (N) fertilizer to maximize yield, but N fertilizers are easily lost to surrounding ecosystems where they contribute to water pollution and greenhouse gas concentrations. Determination of the optimum N fertilizer input is complex because the amount of N produced from soil organic matter varies with time, space and management. Indicators of soil N availability may help to guide requirements for N fertilizer inputs and are increasingly viewed as indicators of soil health To address these challenges and improve N availability indicators, project 4550 “Improving nitrogen availability indicators by emphasizing correlations between gross nitrogen mineralization and the quality and quantity of labile organic matter fractions” addressed the following objectives: Link the quantity and quality of labile soil organic matter fractions to indicators of soil fertility and environmental quality including: i) laboratory potential net N mineralization ii) in situ gross N mineralization iii) in situ N accumulation on ion exchange resins iv) crop uptake of N from mineralized soil organic matter sources (non-fertilizer N), and v) soil nitrate pool size. Evaluate and compare the potential for hot water extractable organic matter (HWEOM) and particulate organic matter quantity and quality to characterize soil N dynamics in biophysically variable Israeli and U.S. agroecosystems that are managed with different N fertility sources. Ultimately, we sought to determine if nitrogen availability indicators are the same for i) gross vs. potential net N mineralization processes, ii) diverse agroecosystems (Israel vs. US) and, iii) management strategies (organic vs. inorganic N fertility sources). Nitrogen availability indicators significantly differed for gross vs. potential N mineralization processes. These results highlight that different mechanisms control each process. Although most research on N availability indicators focuses on potential net N mineralization, new research highlights that gross N mineralization may better reflect plant N availability. Results from this project identify the use of ion exchange resin (IERs) beads as a potential technical advance to improve N mineralization assays and predictors of N availability. The IERs mimic the rhizosphere by protecting mineralized N from loss and immobilization. As a result, the IERs may save time and money by providing a measurement of N mineralization that is more similar to the costly and time consuming measurement of gross N mineralization. In further search of more accurate and cost-effective predictors of N dynamics, Excitation- Emission Matrix (EEM) spectroscopy analysis of HWEOM solution has the potential to provide reliable indicators for changes in HWEOM over time. These results demonstrated that conventional methods of labile soil organic matter quantity (HWEOM) coupled with new analyses (EEM) may be used to obtain more detailed information about N dynamics. Across Israeli and US soils with organic and inorganic based N fertility sources, multiple linear regression models were developed to predict gross and potential N mineralization. The use of N availability indicators is increasing as they are incorporated into soil health assessments and agroecosystem models that guide N inputs. Results from this project suggest that some soil variables can universally predict these important ecosystem process across diverse soils, climate and agronomic management. BARD Report - Project4550 Page 2 of 249
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10

Rawinski, John J., and Deborah S. Page-Dumroese. Soil compaction monitoring of the Pool Timber Sale, Rio Grande National Forest, Colorado, 16 years after logging. Ft. Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, 2008. http://dx.doi.org/10.2737/rmrs-gtr-215.

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