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Correlações lineares e espaciais entre atributos físico-químicos de solos de diferentes ambientes de produção de cana-de-açúcar no Noroeste do Estado de São Paulo /Soria, José Eduardo. January 2014 (has links)
Orientador: Marcelo Andreotti / Banca: Morel de Passos e Carvalho / Banca: Marcelo Rodrigo Alves / Resumo: Vários fatores são responsáveis pela variabilidade espacial da produtividade das culturas, dentre eles, destaca-se os atributos físicos e químicos do solo. Objetivou-se avaliar a variabilidade e caracterizar a dependência espacial entre atributos físicos e químicos dos solos na região noroeste do Estado de São Paulo, bem como estudar as correlações lineares e espaciais para identificar as interações entre tais atributos em ambientes de produção de cana-de-açúcar. Para as análises foram utilizados dados do levantamento de solos do Centro de Tecnologia Canavieira realizado na região noroeste de São Paulo, com fornecimento dos dados das coordenadas geográficas, em 638 pontos amostrais pertencentes numa grade não regular, coletados nas profundidades de 0 a 0,25 e 0,25 a 0,50 m. Foram analisadas as frações granulométricas, bem como os da fertilidade do solo e dos ambientes de produção. Foi realizada a análise estatística descritiva e geoestatística para os atributos. Os ambientes de produção para a cultura da cana-de-açúcar apresentaram relação com os atributos do solo, sendo estes capazes de auxiliar na definição do potencial de produção do solo. Os teores de silte, argila, MO, P, K, Ca, Mg, valores de pH, SB, CTC e V% apresentaram correlações lineares e espaciais positivas com o potencial de produção do solo. Enquanto que os teores de areia, Al3+ e m% apresentam correlações negativas com o potencial de produção do solo. Nos mapas de krigagem foi possível verificar áreas de menor e maior potencial de produção para a cultura da cana-de-açúcar, ou seja, identificar onde estão os melhores e os piores ambientes de produção. Portanto, com o auxílio dos mapas de krigagem dos atributos do solo é possível estabelecer zonas específicas de manejo e definir do potencial produtivo para uma determinada área caracterizada como ambiente de produção / Abstract: Several factors are responsible for the spatial variability of crop yields, among them, there is the physical and chemical soil attributes. Aimed to evaluate the variability and characterize the spatial dependence between physical and chemical attributes of soils in the northwestern region of São Paulo State, as well as studying the linear and spatial correlations to identify the interactions between such attributes in sugarcane production environments. Data were used soil survey of the Sugarcane Technology Center conducted in the northwestern region of São Paulo State, with provision of data of geographical coordinates, in 638 points belonging to a non-regular grid for the analyzes were collected at depths from 0 to 0.25 and 0,25 to 0,50 m. The granulometric fractions were analyzed, as well as soil fertility and production environments. Descriptive statistics and geostatistic analysis was performed for the attributes. Sugarcane production environments correlate with soil attributes, which are able to help in defining the production potential of the soil. The silt, clay, organic matter, P, K, Ca, Mg, pH, SB, CEC and V% showed positive linear and spatial correlations with the soil production potential. While the proportions of sand, Al3 + and m% had negative correlations with the production potential of the soil . In kriging maps it was possible to areas of lower and higher sugarcane production potential, in other words identify where the best and the worst production environments are. Therefore, with the aid of kriging maps of soil attributes is to develop specific management zones and define the productive potential to an area characterized as the production environment / Mestre
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Correlações lineares e espaciais entre atributos físico-químicos de solos de diferentes ambientes de produção de cana-de-açúcar no Noroeste do Estado de São PauloSoria, José Eduardo [UNESP] 04 July 2014 (has links) (PDF)
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000801577.pdf: 1804253 bytes, checksum: b82f4753b7bea810e66a912e4f157fc9 (MD5) / Vários fatores são responsáveis pela variabilidade espacial da produtividade das culturas, dentre eles, destaca-se os atributos físicos e químicos do solo. Objetivou-se avaliar a variabilidade e caracterizar a dependência espacial entre atributos físicos e químicos dos solos na região noroeste do Estado de São Paulo, bem como estudar as correlações lineares e espaciais para identificar as interações entre tais atributos em ambientes de produção de cana-de-açúcar. Para as análises foram utilizados dados do levantamento de solos do Centro de Tecnologia Canavieira realizado na região noroeste de São Paulo, com fornecimento dos dados das coordenadas geográficas, em 638 pontos amostrais pertencentes numa grade não regular, coletados nas profundidades de 0 a 0,25 e 0,25 a 0,50 m. Foram analisadas as frações granulométricas, bem como os da fertilidade do solo e dos ambientes de produção. Foi realizada a análise estatística descritiva e geoestatística para os atributos. Os ambientes de produção para a cultura da cana-de-açúcar apresentaram relação com os atributos do solo, sendo estes capazes de auxiliar na definição do potencial de produção do solo. Os teores de silte, argila, MO, P, K, Ca, Mg, valores de pH, SB, CTC e V% apresentaram correlações lineares e espaciais positivas com o potencial de produção do solo. Enquanto que os teores de areia, Al3+ e m% apresentam correlações negativas com o potencial de produção do solo. Nos mapas de krigagem foi possível verificar áreas de menor e maior potencial de produção para a cultura da cana-de-açúcar, ou seja, identificar onde estão os melhores e os piores ambientes de produção. Portanto, com o auxílio dos mapas de krigagem dos atributos do solo é possível estabelecer zonas específicas de manejo e definir do potencial produtivo para uma determinada área caracterizada como ambiente de produção / Several factors are responsible for the spatial variability of crop yields, among them, there is the physical and chemical soil attributes. Aimed to evaluate the variability and characterize the spatial dependence between physical and chemical attributes of soils in the northwestern region of São Paulo State, as well as studying the linear and spatial correlations to identify the interactions between such attributes in sugarcane production environments. Data were used soil survey of the Sugarcane Technology Center conducted in the northwestern region of São Paulo State, with provision of data of geographical coordinates, in 638 points belonging to a non-regular grid for the analyzes were collected at depths from 0 to 0.25 and 0,25 to 0,50 m. The granulometric fractions were analyzed, as well as soil fertility and production environments. Descriptive statistics and geostatistic analysis was performed for the attributes. Sugarcane production environments correlate with soil attributes, which are able to help in defining the production potential of the soil. The silt, clay, organic matter, P, K, Ca, Mg, pH, SB, CEC and V% showed positive linear and spatial correlations with the soil production potential. While the proportions of sand, Al3 + and m% had negative correlations with the production potential of the soil . In kriging maps it was possible to areas of lower and higher sugarcane production potential, in other words identify where the best and the worst production environments are. Therefore, with the aid of kriging maps of soil attributes is to develop specific management zones and define the productive potential to an area characterized as the production environment
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Atributos bioquímicos como indicadores da qualidade de solo em florestas de Araucaria angustifolia (Bert.) O. Ktze. no estado de São Paulo. / Biochemichal attributes as soil quality indicator in Araucaria angustifolia (Bert.). Ktze. forests in the State of São Paulo.Fernanda de Carvalho 27 July 2005 (has links)
Araucaria angustifolia, espécie brasileira considerada a mais explorada devido à qualidade de sua madeira, encontra-se na atualidade ameaçada de extinção. Diante deste fato a preservação dos remanescentes torna-se ainda mais importante, considerando que a extinção de uma única espécie pode comprometer todo um ecossistema. O objetivo deste estudo foi verificar a utilização dos atributos bioquímicos como indicadores de qualidade do solo em seis ecossistemas de araucária. Os atributos bioquímicos considerados foram carbono e nitrogênio da biomassa microbiana, respiração basal, quociente metabólico, e atividade das enzimas β-glicosidase, urease e hidrólise do diacetato de fluoresceína (FDA) Os ecossistemas avaliados foram mata com araucária (nativa, nativa com interferência antrópica e reflorestamento) em dois parques estaduais (PECJ e PETAR), localizados em duas diferentes regiões do Estado de São Paulo, Campos do Jordão e Apiaí, respectivamente. Foram selecionadas cinco árvores de araucária por ecossistema, onde, sob a copa de cada uma foram retiradas três amostras de solo na profundidade de 0-10 cm, totalizando quinze amostras por ecossistema. Foram realizadas quatro coletas em estações contrastantes, no inverno de 2002 e 2003 e no verão de 2003 e 2004. Os valores isolados de carbono e nitrogênio da biomassa microbiana, não serviram como indicadores precisos e confiáveis da qualidade do solo quanto os demais parâmetros avaliados. Os atributos bioquímicos que denotam processos edáficos dos ecossistemas (respiração basal, quociente metabólico, FDA e a atividade das enzimas urease e β-glicosidase) mostraram-se mais sensíveis para captar as alterações ocorridas no ambiente, e os valores encontrados para estes atributos sugerem que os ecossistemas avaliados sejam sustentáveis, onde a cobertura vegetal e rizosfera seriam importantes para a manutenção de sua funcionalidade. / Brazil Pine (Araucaria angustifolia) has been the most explored Brazilian tree species due to its high quality wood and nowadays it is endangered of extinction. Therefore the preservation of the remainders becomes even more important, considering that the extinction of one species could endanger the whole ecosystem. The objective of this study was to evaluate the use of biochemichal soil attributes as soil quality indicators in six Brazil Pine ecosystems. The following biochemichal attributes were evaluated: carbon and nitrogen of the microbial biomass, soil respiration, the metabolic quotient, fluorescein diacetate (FDA) hydrolysis and the activities of β-glicosidase and urease. The different Brazil Pine ecosystems that were considered, consisted of native forests, replanted areas, impacted area in the two state parks (PECJ and PETAR), located in two different regions of the State of São Paulo-Brazil, Campos do Jordão and Apiaí, respectively. Five Pine trees for each ecosystems were selected and three 0-10cm deep soil samples were collected under the crown of each tree, totalizing fifteen samples. The samplings were carried out in the winter of 2002 and 2003 and in the summer of 2003 and 2004. The carbon and nitrogen microbial biomass by themselves were less sensitive than other attributes as indicators of soil quality. Parameters related to soil processes in the ecosystems (soil respiration, metabolic quotient, FDA hydrolysis and the enzymatic activity of urease and β-glicosidase were more responsive to environmental disturbance. Nevertheless, these parameters suggest that all evaluated the ecosystems are sustainable, and that the vegetation (rhizosphere) is very important for maintenance of its functionality.
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Biologically relevant characteristics of dissolved organic carbon (DOC) from soilBowen, Susan January 2006 (has links)
Of the organic matter in soils typically < 1% by weight is dissolved in the soil solution (dissolved organic matter; DOM). DOM is a continuum of molecules of various sizes and chemical structures which has largely been operationally defined as the fraction of total organic carbon in an aqueous solution that passes through a 0.45 µm filter. Although only representing a relatively small proportion, it represents the most mobile part of soil organic carbon and is probably enriched with highly labile compounds. DOM acts as a source of nutrients for both soil and aquatic micro-organisms, influences the fate and transport of organic and inorganic contaminants, presents a potential water treatment problem and may indicate the mobilisation rate of key terrestrial carbon stores. The objective of this research was to ascertain some of the biologically relevant characteristics of soil DOM and specifically to determine: (1) the influence of method and time of extraction of DOM from the soil on its biochemical composition and concentration; (2) the dynamics of DOM biodegradation; and, (3) the effects of repeated applications of trace amounts of DOM on the rate of soil carbon mineralization. To examine the influence of method and time of extraction on the composition and concentration of DOM, soil solution was collected from a raised peat bog in Central Scotland using water extraction, field suction lysimetry, and centrifugation techniques on a bimonthly basis over the period of a year (Aug 2003 – Jun 2004). Samples were analysed for dissolved organic carbon (DOC), dissolved organic nitrogen (DON), protein, carbohydrate and amino acid content. For all of the sampled months except June the biochemical composition of DOC varied with extraction method, suggesting the biological, chemical and/or physical influences on DOC production and loss are different within the differently sized soil pores. Water-extractable DOC generally contained the greatest proportion of carbohydrate, protein and/or amino acid of the three extraction methods. Time of extraction had a significant effect on the composition of water- and suction-extracted DOC: the total % carbohydrate + protein + amino acid C was significantly higher in Oct than Dec, Feb and Jun for water-extracted DOC and significantly greater in Dec than Aug, Apr and Jun for suction-extracted DOC. There was no significant change in the total % carbohydrate + protein + amino acid C of centrifuge-extracted DOC during the sampled year. Time of extraction also had a significant effect on the % protein + amino acid N in water- and centrifuge-extracted DON: Oct levels were significantly higher than Feb for water-extracted DON and significantly higher in Aug and Apr for centrifuge-extracted DON. Concentrations of total DOC and total DON were also found to be dependent on time of extraction. DOC concentrations showed a similar pattern of variation over the year for all methods of extraction, with concentrations relatively constant for most of the year, rising in April to reach a peak in Jun. DON concentrations in water- and centrifuge-extracted DON peaked later, in Aug. There were no significant seasonal changes in the concentration of suction-extracted DON. A lack of correlation between DOC and DON concentrations suggested that DOC and DON production and/or loss are under different controls. Laboratory-based incubation experiments were carried out to examine the dynamics of DOC biodegradation. Over a 70 day incubation period at 20oC, the DOM from two types of peat (raised and blanket) and four samples of a mineral soil (calcaric gleysol), each previously exposed to a different management strategy, were found to be comprised of a rapidly degradable pools (half-life: 3 – 8 days) and a more stable pool (half-life: 0.4 to 6 years). For all soil types/treatments, excepting raised peat, the total net loss of DOC from the culture medium was greater than could be accounted for by the process of mineralization alone. A comparison between net loss of DOC and loss of DOC to CO2 and microbial biomass determined by direct microscopy suggested that at least some of the differences between DOC mineralised and net DOC loss were due to microbial assimilation and release. Changes in the microbial biomass during the decomposition process showed proliferation followed by decline over 15 days. The protein and carbohydrate fractions showed a complex pattern of both degradation and production throughout the incubation. The effects of repeated applications of trace amounts of litter-derived DOC on the rate of carbon mineralization over a 35 day period were investigated in a laboratory based incubation experiment. The addition of trace amounts of litter-derived DOC every 7 and 10.5 days appeared to ‘trigger’ microbial activity causing an increase in CO2 mineralisation such that extra C mineralised exceeded DOC additions by more than 2 fold. Acceleration in the rate of extra C mineralised 7 days after the second addition suggested that either the microbial production of enzymes responsible for biodegradation and/or an increase in microbial biomass, are only initiated once a critical concentration of a specific substrate or substrates has been achieved. The addition of ‘DOC + nutrients’ every 3.5 days had no effect on the total rate of mineralization. To date DOC has tended to be operationally defined according to its chemical and physical properties. An understanding of the composition, production and loss of DOC from a biological perspective is essential if we are to be able to predict the effects of environmental change on the rate of mineralization of soil organic matter. This research has shown that the pools of DOC extracted, using three different methods commonly used in current research, are biochemically distinct and respond differently to the seasons. This suggests some degree of compartmentalisation of biological processes within the soil matrix. The observed similarities between the characteristics of the decomposition dynamics of both peatland and agricultural DOC suggests that either there is little difference in substrate quality between the two systems or that the microbial community have adapted in each case to maximise their utilisation of the available substrate. The dependency of the concentration and biochemical composition of DOC on the seasons requires further work to ascertain which biotic and/or abiotic factors are exerting control. Published research has focussed on factors such as temperature, wet/dry cycles, and freeze/thawing. The effect of the frequency of doses of trace amounts of DOC on increasing the rate of soil organic C mineralization, evident from this research, suggests that the interval between periods of rainfall may be relevant. It also emphasises how it can be useful to use knowledge of a biological process as the starting point in determining which factors may be exerting control on DOC production and loss.
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Landscape- and regional-scale quantification of nitrous oxide emission from a subhumid transitional grassland-forest regionCorre, Marife Detarot 01 January 1997 (has links)
This study was conducted to obtain landscape- and regional-scale estimates of N<sub>2</sub>O emissions for a representative part of the Black soil zone of Saskatchewan. A 4318-km<sup>2</sup> study region was stratified based on soil texture and land use. At the regional scale, soil texture was the proxy variable used to represent the differences in soil moisture regimes and soil fertility, whereas land use was the surrogate variable used to reflect the differences in N and C cycling. Soil landscapes were selected to cover the range of soil texture and land use characteristics in the study region. At the landscape level, shoulder and footslope complexes were used as the spatial sampling units to cover the range of topographical and soil characteristics within the landscape. At the landform complex level, soil moisture (as assessed by volumetric moisture content and water-filled pore space) was the most important factor controlling N<sub>2</sub>O emission. At the landscape scale, soil moisture was, in turn, influenced by topography, and on the seasonal scale it was affected by climatic factor(s) (e.g., precipitation). The annual N<sub>2</sub>O emissions were calculated as the sum of the spring and the summer to fall fluxes. The spring emission was estimated by interpolating the N<sub>2</sub>O fluxes measured on discrete sampling days, whereas the summer to fall emission was estimated by establishing regression models that related N<sub>2</sub>O fluxes to water-filled pore space. Regional estimates of N<sub>2</sub>O emissions were obtained using the GIS database of soil texture and land use types. The average annual fluxes for fertilized cropped, fallow, pasture, and forest areas, weighted by their areal extent in the different textural areas of the study region, were 2.01, 0.12, 0.04, and 0.02 kg N<sub>2</sub>O-N ha<sup>-1</sup> yr<sup>-1</sup> respectively. The weighted-average annual fluxes for the medium- to fine-textured and sandy-textured areas were 1.31 and 0.04 kg N<sub>2</sub>O-N ha<sup>-1</sup> yr$\sp{-1},$ respectively. For the study region, the weighted-average annual flux was 0.90 kg N<sub>2</sub>O-N ha<sup>-1</sup> yr$\sp{-1}.$
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Soil biogeochemistry and flooding in intermittent streams of the semi-arid Pilbara regionMcIntyre, Rebecca Elise Sinclair January 2009 (has links)
[Truncated abstract] Most of Australia, and large areas of many other continents, is drained by intermittent rivers and streams, however comparatively few biogeochemical studies have been completed for these systems. Intermittent, dryland streams are highly dynamic environments subject to unpredictable and sporadic flow. Natural disturbance from lengthy drought periods and sudden floods are typical for these systems. Without adequate baselines for natural disturbances, it is difficult to quantify other effects from anthropogenic disturbance such as dewatering, land clearing, and urbanisation, or climate change. This thesis presents work from a four-year study examining the biogeochemistry of nitrogen (N), phosphorus (P) and carbon (C) in soils and sediments of two intermittent streams (Barnett Creek and Pirraburdoo Creek) in the Pilbara region of north-west Australia. The Pilbara is an area of ancient geology and highly weathered environments that is undergoing rapid development yet is poorly understood from an ecological perspective. The principal objectives of this thesis were to determine: i) how flooding affects the spatiotemporal patterns of nutrients in intermittent stream landscapes; ii) the role of flooding in N and C mineralisation and microbial dynamics; and iii) the connections between benthic algae, microbes and nutrient availability in channel sediments. To address these objectives, three field studies and two incubation experiments were conducted. Field studies at Barnett Creek indicated that flooding reduced the spatial heterogeneity of available soil nutrients and microbes in the stream landscape, and that topography (relative elevation) in the stream landscape was of less importance in influencing nutrient and microbial patterns than flooding or landscape position. ... Field studies at Pirraburdoo Creek indicated that microbial biomass and activity increased in benthic algal mats during mat senescent stages, and decreased after flooding when mat biomass peaked. Benthic algae grew rapidly in gravel run environments after flooding, while declining in pools, and demonstrated moderate N limitation and strong P limitation. Pools had two to eight times greater NO3-N, three to five times more total N, and two to three times more labile P, OC and total C than either pools after flooding, or runs before or after flooding. Hence, the pools at Pirraburdoo Creek represented a local, interflood store of nutrients in otherwise nutrient-poor landscape, when connectivity to upstream reaches or upland environments was weak or non-existent. This thesis provides the first detailed analysis of soil and sediment biogeochemical responses to flooding for intermittent streams in the Pilbara region and for semi-arid Australia. Further pressing questions raised by this work include: What is the key pulse size and frequency for maintaining Pilbara riparian communities as well as soil microbial function? How do the spatio-temporal nutrient and microbial patterns observed persist over (i) multi-decadal scales, (ii) mega-spatial (larger landscape to regional) scales, (iii) different flood frequency-magnitude regimes, and (iv) different stream sizes? Stream biogeochemistry is a burgeoning field, and it is therefore reasonable to expect such existing gaps in knowledge may be addressed in the near future.
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The Chemistry of Acidic Soils in Humid, Temperate Forested Watersheds with Emphasis on Phosphorus, Aluminum and IronSanClements, Michael January 2009 (has links) (PDF)
No description available.
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The investigation of iron and mineral deficiency associated with the practice of geophagiaVan Wyk, Mari January 1900 (has links)
Thesis (M. Tech. (Biomedical Technology)) -- Central University of technology, Free State, [2013] / Introduction: Geophagia, a subcategory of pica, is the practice of persistently and deliberately eating earthy or soil like substances. A definite cause for the practice of geophagia is yet to be established, but some theories claim that the soil holds nutritional value to the geophagist.
Method: Geophagic woman in the QwaQwa area between the ages of 18 and 45 years were identified by means of a questionnaire. A test group, consisting of 48 women in the habit of consuming soil, and a control group, consisting of 35 non geophagous women, were identified. Subjects in the control group were chosen from the same household or in the same area as the test subjects. On each subject, of both the test group and the control group, the following tests were done: total serum iron, transferrin, ferritin, calcium, magnesium, phosphate and albumin. The results obtained were statistically analysed and compared. Biochemical results were compared with haematology results obtained by another researcher, using the same test group and control group subjects.
Results: In the test group, 75% of the individuals had results indicative of iron deficiency, compared to only 26% in the control group. The haematology results also indicate anaemia in the test group, most probably brought on by iron deficiency. There was no significant difference in mineral results between the test- and control group. Thus no association could be established between soil consumption and mineral status. Conclusion: In relation to non-geophagous women, people who consume soil have a tendency toward iron deficiency. It is impossible to ascertain whether the iron deficiency caused the craving for soil, or whether the consumption of soil caused the iron deficiency. No definite association could be made between soil consumption and mineral status.
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Association between geophagia and haematological parameters of iron deficiency anaemia amongst geophagic Qwa-Qwa womenRaphuthing, Manneheng. Violet. January 1900 (has links)
Thesis (M. Tech. (Biomedical Technology)) -- Central University of Technology, Free State, [2014] / Pica is the habitual eating of non-food substances by humans and animals. It has
different subgroups and these are defined by the ingested substance. Moreover,
geophagia is a type of pica that refers to the consistent eating of mostly earth and
earth-like substances such as clay and soil. It is observed in both sexes, all age
groups and in different ethnic groups around the world. There are many reasons
people give for the practice of geophagia, such as culture, hunger and health being
the most prominent. Geophagic materials differ in texture, colour and taste. Soil
colour classification according to the Munsell soil classification, which uses hues,
values and chroma, sometimes differ with the soil colour being noticeable with the
naked eye. However, geophagic clays from Qwa-Qwa are white and contain kaoline.
Geophagic materials are believed to augment mineral deficiency, especially
magnesium, calcium and iron. Geophagia is practised mainly by females, especially
during their child bearing years. Females are more prone to iron deficiency anaemia
due to their monthly menstruation cycle. Iron deficiency is the most common cause
of anaemia and is classified as hypochromic microcytic anaemia (HMA). This study
focused on the health aspect of geophagia. The research question seeks to explore
whether there is an association between geophagia and the haematological
parameters of iron deficiency anaemia. Geophagia seems to be linked with the
occurrence of anaemia, but not iron deficiency anaemia, although it is implied. It is
not known if the practice of geophagia causes iron deficiency anaemia or if it is
because of iron deficiency anaemia that people practise geophagia. A pilot study
was done in 2007, and the results of that study prompted that this study be
performed on a bigger scale.
The lack of information regarding the quantity, frequency and type of geophagic
material consumed the impact of geophagia on haematological parameters and the
iron status of the geophagists made it important that the primary existence of the
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relationship be investigated. In addition, research to establish whether there is a
relationship between geophagia and haematological parameters of iron deficiency
anaemia, has not been undertaken in South Africa, especially on non-pregnant
women. Geophagia seems to always be accompanied by the subject of iron
deficiency anaemia and especially its prevalence in females. The bigger geophagia
project was therefore an ideal opportunity to do a specific survey on geophagic
women.
This was a cross-sectional study, consisting of 36 control women and 47 geophagic
women, aged between 18-45 years. The participants completed a questionnaire to
determine the geophagic practices, which included the colour of the clay, how
frequent the clay was consumed, how much was consumed and for how long it has
been consumed. Nutritional status was assessed using a food frequency
questionnaire. Blood was drawn to assess the haematological and iron status of the
participants.
The participants of the study were within the required age range, with no significant
difference between the groups (p-value=0.7914). The most consumed colour of clay
was white and white clay contains kaoline, which has the ability to absorb iron in the
duodenum. The majority of the participants consumed 40 grams of clay on a daily
basis, with most of the participants having done so for 5 years. Diet was ruled out as
the cause of iron deficiency.
The haematological parameters indicated that the geophagic group (43%) were
inclined to have hypochromic microcytic anaemia, while a small percentage of
control groups (8%) had HMA; this was revealed by the red cell parameters and red
cell indices. In addition, the odds ratio for the haematological results revealed that
the probability of a geophagic person developing anaemia was two times greater
than that of a non-geophagic person. Platelet results partially ruled out bleeding as
a cause of anaemia. The median red cell distribution width indicated that the
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geophagic group was inclined to have anisocytosis. The geophagic group was
found to have iron deficiency (75%), whilst the control group had a small
percentage with iron deficiency (22%), which was validated by the serum ferritin,
serum iron and saturated transferrin (chemical analysis). The odds ratio revealed
that the probability of a geophagic person being iron deficient is 3 times greater
than that of a non-geophagic person. The strongest association is seen with iron
study findings, because being iron deficient showed the highest odd ratio than the
association with red cell morphology and even haemoglobin. Thus, participants
were more iron deficient than suffering from iron deficiency anaemia.
Inflammatory and parasitic indicators proved that inflammation and infection was
uncommon in both groups, and therefore did not compromise the credibility of the
iron study results. Inflammatory indicators (white blood cells, erythrocyte
sedimentation rate and C-reactive protein) ruled out inflammation, whilst eosinophil
count showed no indication of parasitic infection for both geophagic and control
groups.
To conclude, the study found that an association exists between geophagia and
haematological parameters of iron deficiency anaemia amongst geophagic women
in Qwa-Qwa, in that geophagic material contributes to iron deficiency anaemia.
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Soil Iron, Aluminum, and Phosphorus Dynamics in Response to Long-Term Nitrogen and Sulfur Additions at the Bear Brook Watershed in MaineSherman, Jessica F. January 2005 (has links) (PDF)
No description available.
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