Increased amounts of pesticide production and application of pesticides for agriculture, plant protection and animal health has resulted in soil, water and air pollution, consequently relating a serious risk to the environment and also to human health. Pesticides include several groups of compounds, herbicides, insecticides, rodenticides and fumigants consisting of several hundred individual chemicals. Herbicides are an integral pan of modem agriculture and for industries requiring total vegetation control. Most herbicides are soil applied and more and more concern is raised that herbicides not only affect target organisms but also the microbial community present in soil. The ESKOM sub-station Zeus, in Mpumalanga (South Africa) used to apply an industrial weed control program for the eradication of vegetation, which led to the contamination of soil by several herbicides. These herbicides consisted of Bromacil, Tebuthiuron and Ethidimuron which are all photosynthesis inhibitors, more specifically, they disrupt the plastoquinone protein during electron transport at photosystem I1 (PSII). In this study the effect of biostimulation and bio-augmentation of a specific bioremediation agent (B350) as prescribed by ESKOM, on residual herbicides, Bromacil, Tebuthiuron and Ethidimuron was evaluated by monitoring the soil physical and chemical properties, microbial attributes, including potential microbial activity and community structure, as well as the physiological effect experienced by plants (Cynodoh dactylon and Zea mays). Results from soil physical and chemical analyses were correlated with results obtained for the functional and structural diversity of microbial communities. All results were investigated through statistical and multivariate analysis and the most prominent soil physical and chemical parameters that influence the biological and biochemical properties of the soil were identified. Results obtained from this study indicated that there were no significant difference (p < 0.05) between the treatments, with bioremediation agent, irradiated agent and without the agent based on results obtained from soil microbial properties and plant physiology. Before the trial started the uncontaminated soil showed an active microbial function, characterised by dehydrogenase, urease and arylsulphatase activity, but community structure was not very diverse. The contaminated soil, irradiated contaminated soil and silica sand showed less enzymatic function and was characterised by phospholipid fatty acid groups, mid-branched saturated fatty acids, terminally branched saturated fatty acids, normal saturated fatty acids and monosaturated fatty acids which are indicative of microorganisms that survive better in harsh environments. Three weeks after the addition of the specific bioremediation took place, the uncontaminated soil showed an increase in P-glucosidase activity and percentage organic carbon (%C), which could be a result of the presence of available plant material. Furthermore, an increase in major PLFA groups were seen, suggesting that an increase in diversity within the soil community occurred. The contaminated soil, irradiated contaminated soil and silica sand once again was characterised by a low microbial function and diversity, showing no improvement. Fluorescence data clearly show a decline in PS 11 function that result in the decline of the rate of photosynthesis, which was seen from COz gas exchange rates. Furthermore, the decrease in photosynthetic activity after three weeks was too severe to supply additional information about the mechanism within photosynthesis or the photoprotective mechanisms. A detailed study was conducted in which a 3: 1 dilution of contaminated soil with silica sand, was also monitored for changes within plant physiology. Results revealed that inhibition of PS I1 function already takes place within a few days time and the decline in photosynthesis is as a result of electron transport that does not supply adenosine triphosphate (ATP) and P-nicotinamide adenine dinucleotide (NADPH) to the Calvin cycle (or Reductive Pentose Phosphate pathway). It does not appear that rubulose-1,sbisphosphate carboxylase-oxygenase (Rubisco) is affected within the Calvin cycle. As a result of PS I1 function failure, reaction centres are damaged by the production of harmful singlet oxygen and photoprotective mechanisms (xanthophyll cycle) can not be activated. Thus, except for dealing with ineffective electron transport, additional damage is caused to physiological functions. After six weeks a decrease in the estimated viable biomass for all growth mediums was found. Results of the of trans- to cis- monoenoic fatty acids and cyclopropyl fatty acids to their monoenoic precursors ratios indicated that the soil microbial community for the contaminated growth mediums, all experienced nutritional stress throughout this trail. The specific bioremediation agent (B350) used, seemed to have no effect on the microbial function and community structure within soil and as agent had no effect on the residual herbicides or the plant physiology which experienced an extreme decline in major metabolic functions. / Thesis (M. Environmental Science)--North-West University, Potchefstroom Campus, 2

Mining activities cause severe disturbance to the soil environment in terms of soil quality and productivity and are of serious concern worldwide. Under South African legislation, developers are required to ecologically rehabilitate damaged environments. The application of agronomic approaches for the rehabilitation of coal discard sites has failed dismally in the arid areas of southern Africa. It is obvious that compliance with mitigation and rehabilitation requirements cannot be enforced without a thorough understanding of the ecological principles that ensure ecological stability and subsequent sustainability of soil ecosystems. Soil micro organisms are crucial role-players in the processes that make energy and nutrients available for recycling in the soil ecosystem. Poor management practices and other negative impacts on soil ecosystems affect both the physical and chemical properties of soil, as well as the functional and structural properties of soil microbial communities. Disturbances of soil ecosystems that impact on the normal functioning of microbial communities are potentially detrimental to soil formation, energy transfers, nutrient cycling, plant reestablishment and long-term stability. In this regard, an extensive overview of soil properties and processes indicated that the use of microbiological and biochemical soil properties, such as microbial biomass, enzymatic activity and the analysis of microbial community structure by the quantification of specific signature lipid biomarkers are useful as indicators of soil ecological stress or restoration properties because they are more responsive to small changes than physical and chemical characteristics. In this study, the relationship between the physical and chemical characteristics and different biological indicators of soil quality in the topsoil covers of seven coal discard sites under rehabilitation in South Africa, as well as three reference sites was investigated. Through the assimilation of basic quantitative data and the assessment of certain physical, chemical and biological properties of the topsoil covers obtained from the various coal discard sites as well as the reference sites, the relative success or progress of rehabilitation and the possible correlation between the biological indicators of soil quality and the establishment of self sustaining vegetation covers was determined. Results from soil physical and chemical analyses and percentage vegetation cover were correlated with the results obtained for the functional and structural diversity of microbial communities at the various sites. All results were investigated through statistical and multivariate analysis and the most prominent physical and chemical parameters that influence the biological and biochemical properties of the soil and possibly the establishment of self-sustainable vegetation cover on these mine-tailing sites were identified. Results obtained from this study indicated no significant difference (p>0.05) between the various discard sites based on conventional microbiological enumeration techniques. However, significant differences (p<0.05) could be observed between the three reference sites. All enzymatic activities assayed for the rehabilitation sites, with the exception of urease and alkaline phosphatase displayed a strong, positive association with the organic carbon content (%C). Ammonium concentration had a weak association with all the enzymes studied and pH only showed a negative association with acid phosphatase activity. A positive association was observed between the viable microbial biomass, vegetation cover and the organic carbon content, ammonium, nitrate and phosphorus concentrations of the soil. The various rehabilitation and reference sites could be differentiated based on the microbial community structure as determined by phospholipid fatty acid (PLFA) analysis. It is hypothesised that the microbial community structure of the Hendrina site is not sustainable when classified along an r-K gradient and that the high percentage of vegetation cover and high levels of estimated viable microbial biomass are an artificial reflection of the current management practices being employed at this site. Results obtained during this study, suggest that an absence or low percentage of vegetation cover and associated lower organic matter content of the soil have a significant negative impact on soil biochemical properties (enzymatic activity) as well as microbial population size. Furthermore, prevailing environmental physico-chemical and management characteristics significantly influences the vegetation cover and subsequently the microbial community structure. The results indicate that the microbial ecosystems in the coal discard sites could become more stable and ecologically self-regulating, provided effective management to enhance the organic carbon content of the soil. This could enhance nutrient cycling, resulting in changes of soil structure and eventually an improved soil quality which could facilitate the establishment of self sustaining vegetation cover. Results obtained during this study suggest that a polyphasic assessment of physical and chemical properties; microbial activities by enzymatic analysis; the characterisation of microbial community structure by analysis of phospholipid fatty acids; and the multifactorial analysis of the data obtained can be used as complementary assessment criteria for the evaluation of the trend of rehabilitation of mine tailings and discard sites. Strategic management criteria are recommended based on the soil quality environmental sustainability indices to facilitate the establishment of self sustainable vegetation covers. The contribution of this research to soil ecology is significant with regards to the intensive investigation and explanation of characteristics and processes that drive ecological rehabilitation and determine the quality of the soil environment. The multidisciplinary approach that is proposed could, furthermore, assist in the successful rehabilitation and establishment of self-sustaining vegetation covers at industrially disturbed areas, as well as assist in improving degraded soil quality associated with both intensive and informal agriculture. Additionally, this approach could negate the negative social and environmental impacts frequently associated with these activities. / Thesis (M. Environmental Science)--North-West University, Potchefstroom Campus, 2004.

Increased amounts of pesticide production and application of pesticides for agriculture, plant protection and animal health has resulted in soil, water and air pollution, consequently relating a serious risk to the environment and also to human health. Pesticides include several groups of compounds, herbicides, insecticides, rodenticides and fumigants consisting of several hundred individual chemicals. Herbicides are an integral pan of modem agriculture and for industries requiring total vegetation control. Most herbicides are soil applied and more and more concern is raised that herbicides not only affect target organisms but also the microbial community present in soil. The ESKOM sub-station Zeus, in Mpumalanga (South Africa) used to apply an industrial weed control program for the eradication of vegetation, which led to the contamination of soil by several herbicides. These herbicides consisted of Bromacil, Tebuthiuron and Ethidimuron which are all photosynthesis inhibitors, more specifically, they disrupt the plastoquinone protein during electron transport at photosystem I1 (PSII). In this study the effect of biostimulation and bio-augmentation of a specific bioremediation agent (B350) as prescribed by ESKOM, on residual herbicides, Bromacil, Tebuthiuron and Ethidimuron was evaluated by monitoring the soil physical and chemical properties, microbial attributes, including potential microbial activity and community structure, as well as the physiological effect experienced by plants (Cynodoh dactylon and Zea mays). Results from soil physical and chemical analyses were correlated with results obtained for the functional and structural diversity of microbial communities. All results were investigated through statistical and multivariate analysis and the most prominent soil physical and chemical parameters that influence the biological and biochemical properties of the soil were identified. Results obtained from this study indicated that there were no significant difference (p < 0.05) between the treatments, with bioremediation agent, irradiated agent and without the agent based on results obtained from soil microbial properties and plant physiology. Before the trial started the uncontaminated soil showed an active microbial function, characterised by dehydrogenase, urease and arylsulphatase activity, but community structure was not very diverse. The contaminated soil, irradiated contaminated soil and silica sand showed less enzymatic function and was characterised by phospholipid fatty acid groups, mid-branched saturated fatty acids, terminally branched saturated fatty acids, normal saturated fatty acids and monosaturated fatty acids which are indicative of microorganisms that survive better in harsh environments. Three weeks after the addition of the specific bioremediation took place, the uncontaminated soil showed an increase in P-glucosidase activity and percentage organic carbon (%C), which could be a result of the presence of available plant material. Furthermore, an increase in major PLFA groups were seen, suggesting that an increase in diversity within the soil community occurred. The contaminated soil, irradiated contaminated soil and silica sand once again was characterised by a low microbial function and diversity, showing no improvement. Fluorescence data clearly show a decline in PS 11 function that result in the decline of the rate of photosynthesis, which was seen from COz gas exchange rates. Furthermore, the decrease in photosynthetic activity after three weeks was too severe to supply additional information about the mechanism within photosynthesis or the photoprotective mechanisms. A detailed study was conducted in which a 3: 1 dilution of contaminated soil with silica sand, was also monitored for changes within plant physiology. Results revealed that inhibition of PS I1 function already takes place within a few days time and the decline in photosynthesis is as a result of electron transport that does not supply adenosine triphosphate (ATP) and P-nicotinamide adenine dinucleotide (NADPH) to the Calvin cycle (or Reductive Pentose Phosphate pathway). It does not appear that rubulose-1,sbisphosphate carboxylase-oxygenase (Rubisco) is affected within the Calvin cycle. As a result of PS I1 function failure, reaction centres are damaged by the production of harmful singlet oxygen and photoprotective mechanisms (xanthophyll cycle) can not be activated. Thus, except for dealing with ineffective electron transport, additional damage is caused to physiological functions. After six weeks a decrease in the estimated viable biomass for all growth mediums was found. Results of the of trans- to cis- monoenoic fatty acids and cyclopropyl fatty acids to their monoenoic precursors ratios indicated that the soil microbial community for the contaminated growth mediums, all experienced nutritional stress throughout this trail. The specific bioremediation agent (B350) used, seemed to have no effect on the microbial function and community structure within soil and as agent had no effect on the residual herbicides or the plant physiology which experienced an extreme decline in major metabolic functions. / Thesis (M. Environmental Science)--North-West University, Potchefstroom Campus, 2

Mining activities cause severe disturbance to the soil environment in terms of soil quality and productivity and are of serious concern worldwide. Under South African legislation, developers are required to ecologically rehabilitate damaged environments. The application of agronomic approaches for the rehabilitation of coal discard sites has failed dismally in the arid areas of southern Africa. It is obvious that compliance with mitigation and rehabilitation requirements cannot be enforced without a thorough understanding of the ecological principles that ensure ecological stability and subsequent sustainability of soil ecosystems. Soil micro organisms are crucial role-players in the processes that make energy and nutrients available for recycling in the soil ecosystem. Poor management practices and other negative impacts on soil ecosystems affect both the physical and chemical properties of soil, as well as the functional and structural properties of soil microbial communities. Disturbances of soil ecosystems that impact on the normal functioning of microbial communities are potentially detrimental to soil formation, energy transfers, nutrient cycling, plant reestablishment and long-term stability. In this regard, an extensive overview of soil properties and processes indicated that the use of microbiological and biochemical soil properties, such as microbial biomass, enzymatic activity and the analysis of microbial community structure by the quantification of specific signature lipid biomarkers are useful as indicators of soil ecological stress or restoration properties because they are more responsive to small changes than physical and chemical characteristics. In this study, the relationship between the physical and chemical characteristics and different biological indicators of soil quality in the topsoil covers of seven coal discard sites under rehabilitation in South Africa, as well as three reference sites was investigated. Through the assimilation of basic quantitative data and the assessment of certain physical, chemical and biological properties of the topsoil covers obtained from the various coal discard sites as well as the reference sites, the relative success or progress of rehabilitation and the possible correlation between the biological indicators of soil quality and the establishment of self sustaining vegetation covers was determined. Results from soil physical and chemical analyses and percentage vegetation cover were correlated with the results obtained for the functional and structural diversity of microbial communities at the various sites. All results were investigated through statistical and multivariate analysis and the most prominent physical and chemical parameters that influence the biological and biochemical properties of the soil and possibly the establishment of self-sustainable vegetation cover on these mine-tailing sites were identified. Results obtained from this study indicated no significant difference (p>0.05) between the various discard sites based on conventional microbiological enumeration techniques. However, significant differences (p<0.05) could be observed between the three reference sites. All enzymatic activities assayed for the rehabilitation sites, with the exception of urease and alkaline phosphatase displayed a strong, positive association with the organic carbon content (%C). Ammonium concentration had a weak association with all the enzymes studied and pH only showed a negative association with acid phosphatase activity. A positive association was observed between the viable microbial biomass, vegetation cover and the organic carbon content, ammonium, nitrate and phosphorus concentrations of the soil. The various rehabilitation and reference sites could be differentiated based on the microbial community structure as determined by phospholipid fatty acid (PLFA) analysis. It is hypothesised that the microbial community structure of the Hendrina site is not sustainable when classified along an r-K gradient and that the high percentage of vegetation cover and high levels of estimated viable microbial biomass are an artificial reflection of the current management practices being employed at this site. Results obtained during this study, suggest that an absence or low percentage of vegetation cover and associated lower organic matter content of the soil have a significant negative impact on soil biochemical properties (enzymatic activity) as well as microbial population size. Furthermore, prevailing environmental physico-chemical and management characteristics significantly influences the vegetation cover and subsequently the microbial community structure. The results indicate that the microbial ecosystems in the coal discard sites could become more stable and ecologically self-regulating, provided effective management to enhance the organic carbon content of the soil. This could enhance nutrient cycling, resulting in changes of soil structure and eventually an improved soil quality which could facilitate the establishment of self sustaining vegetation cover. Results obtained during this study suggest that a polyphasic assessment of physical and chemical properties; microbial activities by enzymatic analysis; the characterisation of microbial community structure by analysis of phospholipid fatty acids; and the multifactorial analysis of the data obtained can be used as complementary assessment criteria for the evaluation of the trend of rehabilitation of mine tailings and discard sites. Strategic management criteria are recommended based on the soil quality environmental sustainability indices to facilitate the establishment of self sustainable vegetation covers. The contribution of this research to soil ecology is significant with regards to the intensive investigation and explanation of characteristics and processes that drive ecological rehabilitation and determine the quality of the soil environment. The multidisciplinary approach that is proposed could, furthermore, assist in the successful rehabilitation and establishment of self-sustaining vegetation covers at industrially disturbed areas, as well as assist in improving degraded soil quality associated with both intensive and informal agriculture. Additionally, this approach could negate the negative social and environmental impacts frequently associated with these activities. / Thesis (M. Environmental Science)--North-West University, Potchefstroom Campus, 2004.

Forested riparian zones, which function as a buffer between agricultural fields and streams, filter out contaminants and sediment from the fields thereby improving water quality, cool the water with shade from trees, stabilize the stream bank and provide habitat for wildlife. However, in many agricultural areas, riparian vegetation has been removed for crop production or pasture purposes. Riparian restoration or rehabilitation is a way of restoring riparian ecosystem functions. This study examines the effect of riparian rehabilitation via tree planting along a first-order creek in Southern Ontario, 25 years after rehabilitation. Litter input, soil quality parameters and soil CO2 production rates were determined for the rehabilitated riparian zone, a grass-forb riparian zone and a natural forest riparian zone. Total litter input was 480, 580 and 295 g m-2 y-1 for the rehabilitated riparian zone, grass riparian zone and forest riparian zone, respectively. Soil bulk density was higher and hydraulic conductivity was lower for the rehabilitated riparian zone compared to the grass riparian zone and forest riparian zone. The concentration and soil stock of organic carbon and total nitrogen was lowest for the rehabilitated riparian zone compared to the grass riparian zone and forest riparian zone which were similar. The effect of riparian zone on soil CO2 production rates varied over the season. From spring to mid-summer, rates were 167, 224 and 104 mg C m-2 h-1 for the rehabilitated riparian zone, grass riparian zone and forest riparian zone, respectively. Soil CO2 production rates did not differ significantly (p < 0.05) between riparian zones for late summer and fall sampling dates. Soil CO2 production rates were significantly negatively correlated with soil C/N and positively correlated with soil pH and litter input. Soil CO2 production rates were positively correlated with soil temperature (r = 0.32) and negatively correlated with soil moisture (r = -0.48). Of the three riparian zones, the natural forest riparian zone exhibited the least amount of seasonal fluctuation for soil CO2 production rates, soil moisture and temperature. Results from this research indicated that more time is needed before soil quality and soil CO2 production rates of the rehabilitated riparian zone reach values similar to the natural forest riparian zone.

Σκοπός της παρούσας εργασίας είναι η μελέτη της επίδρασης των εισροών στην ποιότητα του εδάφους των καλλιεργειών, στο οροπέδιο της κοινότητας Ομαλών στη νήσο Κεφαλληνία, μέσω της αξιοποίησης των στοιχείων που προκύπτουν από την δομή και την περιγραφή του συγκεκριμένου αγροτικού οικοσυστήματος. Η μελέτη έγινε σε βιολογικούς και συμβατικούς ελαιώνες και αμπελώνες και διήρκησε 1 χρόνο. Κατά την διάρκεια του χρόνου αυτού, πραγματοποιήθηκαν δειγματοληψίες από τα υπό μελέτη εδάφη και προσδιορίσθηκαν χημικές και βιολογικές ιδιότητες. Συγκεκριμένα προσδιορίστηκαν το pH, η Ικανότητα Ανταλλαγής Κατιόντων, η οργανική ουσία, η Ηλεκτρική αγωγιμότητα, ο φώσφορος, τα ανταλλάξιμα κατιόντα K, Na και Mg, το ολικό άζωτο, το βόριο τα νιτρικά και η εδαφική αναπνοή. Για την αξιοποίηση των αποτελεσμάτων των εδαφολογικών αναλύσεων ήταν απαραίτητη η γνώση των καλλιεργητικών πρακτικών που εφαρμόζονται στα αγροτεμάχια καθώς και οι ποσότητες των εισροών σε αυτά. Για το σκοπό αυτό πραγματοποιήθηκαν συνεντεύξεις σε αγρότες της περιοχής με την χρήση ερωτηματολογίων ανοιχτού τύπου. Από τα ερωτηματολόγια προέκυψε ότι η υψηλότερη ενεργειακή εισροή στο εδαφικό υποσύστημα είναι η κοπριά τόσο στην περίπτωση της βιολογικής καλλιέργειας όσο και συμβατικής καλλιέργειας ελιάς και αμπέλου. Η εντατική χρήση υψηλών ποσοτήτων κοπριάς συμβάλλει στην βελτίωση των χημικών και βιολογικών ιδιοτήτων του εδάφους αλλά εγκυμονεί κινδύνους για την ποιότητα του. / In the following research the effects of agroecosystem inputs on soil quality of crops at plateau Omala of Cephalonia island via the exploitation of elements that result through the study of the structure and the description of particular agroecosystem, were studied. The research had a duration of above 1 year, in which samplings from the soil and their chemical and biological attributes were not only realized but also evaluated concretely pH,Cation Exchange Capacity, organic matter, Electrical Conductivity, the phosphor, Exchangeable Cations K, Na and Mg, total N, NO3, the boron and the microbial rate, were measured. For the exploitation of results of soil analysis it was essential to have obtain knowledge of farming practices that is applied in the farmyards as well as the quantities of inputs. This aim was realised through interviews with farmers of the region with the use of open type questionnaires. The result of these questionnaires was that the higher energy input in the soil subsystem is manure. The intensive use of high quantities of manure contributes to the improvement of the chemical and biological attributes of soil but gestates dangers for soil quality.

O presente trabalho teve por objetivo compreender sistemas de produção agrícola e agropecuária a campo pela avaliação da diversidade, funcionalidade e dinâmica espaço-temporal de espécies, assim como pelo padrão de variação da qualidade do solo e dos fatores que a determinam. Para isso, foi avaliado na “Agropecuária Guajuvira” localizada no município de São Miguel das Missões – RS quatro sistemas conservacionistas de produção. Foram eles: 1- sistema agrícola tradicional, representando a sucessão soja/trigo e soja/aveia preta amplamente praticada na região; 2- Sistema agrícola irrigado, semelhante ao anterior, mas, com recente inserção de milho no verão; 3- Sistema integrado de produção agropecuária 1, representando a sucessão soja/pastejo de azevém e 4- Sistema integrado de produção agropecuária 2, representando um sistema misto por apresentar alterações na composição de espécies no inverno pela sucessão soja/aveia preta pastejada, soja/aveia preta não pastejada e soja/nabo forrageiro/trigo O estoque de carbono (EC), estabilidade de agregados do solo (EAS) e índice de manejo de carbono (IMC) foram escolhidos como indicadores da qualidade sistêmica do solo. Seus padrões de variação foram compreendidos pela integração de atributos químicos, físicos e biológicos do solo, assim como por variáveis de paisagem inerentes às unidades amostrais. Os fatores que caracterizaram os sistemas de produção e o uso da análise de caminhos permitiram um maior entendimento de sistemas complexos de produção agrícola e agropecuária a campo. / The aim of this research was to understand agricultural and integrated crop-livestock production systems by the species diversity, functionality and spatial-temporal dynamics evaluation, as well as of the variation pattern of soil quality and factors that determine then. For this, four no-tillage production systems were evaluated on the "Agropecuária Guajuvira" located in São Miguel das Missões county in southern Brazil. The production systems were: 1- Traditional agricultural system, representing the succession soybean/wheat and soybean/black oat widely practiced in the region; 2- Irrigated agricultural system, similar to the previous one, but, with recent insertion of corn in the summer; 3 - Integrated crop-livestock system 1, representing the succession of soybean /grazed ryegrass and 4 - Integrated crop-livestock system 2, representing a mixed system due changes in species composition during winter by succession of soybean/grazed black oat, soybean/no-grazed black oat and soybean/forage radish/wheat The carbon stock (CS), soil aggregate stability (SAS) and carbon management index (CMI) were chosen as systemic soil quality indicators. Their variation patterns were understood by the integration of chemical, physical and biological soil attributes, as well as by landscape variables inherent to the sampling units. The factors that characterized the production systems and the path analysis utilization allowed a greater understanding of complex agricultural and integrated crop-livestock production systems in the field.

Made available in DSpace on 2014-06-11T19:23:10Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-07-22Bitstream added on 2014-06-13T20:50:10Z : No. of bitstreams: 1 yada_mm_me_jabo.pdf: 312702 bytes, checksum: 6f892253bdb3bc5c70ef4a35150b6ce5 (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Os recursos naturais fazem da região amazônica um importante pólo para a agricultura e a exploração mineral. Entretanto, a falta de moderação na exploração causa a diminuição da matéria orgânica do solo com perda de seu potencial produtivo ou de regeneração da mata nativa. A recuperação destas áreas é de fundamental importância até mesmo para a manutenção da atividade física, química e biológica do solo. O plano de recuperação das áreas degradadas iniciou em 1997, uma série de pesquisas com a finalidade de definir estratégias para recuperação da área degradada por mineração de cassiterita na Floresta Nacional do Jamari, em Rondônia. As áreas foram classificadas em diferentes níveis de recuperação. O presente trabalho teve por objetivo avaliar os atributos químicos e bioquímicos nos solos das áreas degradadas pela mineração de cassiterita submetidos aos processos de recuperação nas minas Serra da Onça e Santa Maria. As análises dos atributos químicos e bioquímicos do solo contribuem para a caracterização das áreas degradadas por mineração em processo de recuperação podendo identificar áreas que estão em estágio avançado de recuperação comparado com as áreas de mata e de capoeira / The situation and the environmental resources of Amazon Basin make it import for agriculture and mineral extraction, both causing the destruction of soil organic matter with the loss of the soil fertility, that it became improper to agriculture of is not able to support the restore of the native forest. The recuperation of these areas is important for the maintenance of the physical, chemical and biological activity of the soil and plant growth. The plan of recuperation of degraded areas started in 1997, in a research with the purpose to define strategies for a process of recuperation of the area degraded by mining of tin ore in the National Forest of Jamari, Rondônia state. Different areas had been classified in according to their level of recuperation. The objective of this work was to evaluate chemical and biochemical attributes in soils of degraded areas submitted to mining of tin ore in different stages of restoring process in Amazon Basin. The analyses of quantification of chemistry and biochemistry attributes in degraded soils submitted to recuperation program contribute for the characteristic of the different areas

Made available in DSpace on 2015-03-26T13:53:01Z (GMT). No. of bitstreams: 1 texto completo.pdf: 1113012 bytes, checksum: 32ef94702ba7e7b7fdd2107b8451dd23 (MD5) Previous issue date: 2007-08-01 / Fundação de Amparo a Pesquisa do Estado de Minas Gerais / Agroforestry systems are effective in improving and conserving soil quality. The trees in these systems absorb nutrients from deep soil layers and continually contribute to the soil top layer with litterfall, generating impacts above and below-ground. Our objective was to study the characteristics involved in the nutrient cycling by three species used in agroforestry systems, seeking to contribute to better design and management of the systems. The species selected for the study were ipê-preto (Zeyheria tuberculosa), açoita- cavalo (Luehea grandiflora), mulungu (Erythrina verna), fedegoso (Senna macranthera), ingá (Inga subnuda), papagaio (Aegiphila sellowiana) and avocado (Persea americana). The increase in tree biomass, the contribution of literfall and the contents of nutrients in the aerial tree parts were measured from November 2005 to October 2006. The decomposition rate and release of nutrients of the residues, the contents of chemical and biochemical components of these materials were evaluated. Increases of biomass (kg year-¹ of dry matter per tree, DM) were larger for mulungu (135,4), fedegoso (120,4), açoita-cavalo (99,0), avocado (81,7) and ingá (39,3). The contributions (kg ha-¹ year-¹ of DM) of litter fall were larger for fedegoso (6.086,9), inga (4.331,2), açoita-cavalo (2.397,7) and avocado (2.004,5). The reallocation of nutrients in the green material before the fall of senescent material was larger for N (papagaio and mulungu), P (avocado and fedegoso) and K (papagaio, fedegoso and avocado), reaching values up to 73% for the reallocation of P in avocado. Fedegoso, ingá, açoita-cavalo along with abacate produced litterfall with the largest nutrient content. In general, leaves contained the largest amount of nutrients and there was no difference among seasons when the material of all species was pooled. However, the nutrient contents of each species varied among seasons and plant parts. The decomposition rate, measured using the production of C-CO2, was larger for fedegoso, mulungu, ipê-preto and papagaio than for the other species. Lignin/N and lignin + polifenol/N was correlated to the decomposition rate of the materials of the different species. Among the Leguminosae species, mulungu and fedegoso had the highest decomposition rate (measured with litter bags) and inga the lowest. The largest amount of nitrogen fixation was found for mulungu (22,6%) and ingá (20,6%). Potassium was released quicker and magnesium and calcium slower than other nutrients. The characteristics of the litterfall and their decomposition dynamics were different for the different species. Understanding of these characteristics and processes can contribute to a better design of family agroecological systems that combine productivity and soil and biodiversity conservation. When used in a diversified manner, tree species can contribute to a balanced and constant nutrient cycling. Therefore, diversification of agroforestry systems allows better use of the native trees of the Atlantic Rainforest. / Os sistemas agroflorestais são efetivos em melhorar e conservar a qualidade do solo. As árvores presentes nestes sistemas absorvem nutrientes de camadas profundas do solo e aportam continuamente material orgânico, gerando impactos à superfície e abaixo da superfície do solo. O objetivo deste trabalho foi estudar características envolvidas na ciclagem de nutrientes de espécies arbóreas, visando contribuir para a formulação de estratégias de manejo de sistems agroflorestais. As espécies selecionadas para o estudo foram o ipê-preto (Zeyheria tuberculosa), o açoita-cavalo (Luehea grandiflora), o mulungu (Erythrina verna), o fedegoso (Senna macranthera), o ingá (Ingá subnuda), o papagaio (Aegiphila sellowiana) e o abacate (Persea americana). A produção de biomassa aérea, o aporte de material senescente das espécies, os teores e conteúdos de nutrientes na parte aérea, foram avaliados no período de novembro/2005 a outubro/2006. Também avaliou-se a taxa de decomposição e de liberação de nutrientes dos resíduos e os teores de componentes químicos e bioquímicos que interferem na decomposição e liberação de nutrientes destes materiais. As maiores produções de biomassa da parte aérea das espécies (kg ano-¹de matéria seca por árvore, MS) foram observada para o mulungu (135,4), fedegoso (120,4), açoita-cavalo (99,0), abacate (81,7), e ingá (39,3). Quanto ao material senescente, os maiores aportes (kg ha-¹ ano-¹ de MS) foram observados para o fedegoso (6.086,9), ingá (4.331,2), açoita-cavalo (2.397,7) e abacate (2.004,5). Algumas espécies apresentaram realocação de nutrientes sendo esta maior para P (abacate e fedegoso), N (papagaio e mulungu) e K (papagaio, fedegoso e abacate) chegando a valores de 73% para a realocação de P em abacate. As espécies que aportaram o maior conteúdo de nutrientes por meio do material senescente foram o fedegoso, o ingá, o açoita- cavalo e o abacate. Para o conjunto das espécies o aporte de nutrientes via material senescente não variou significativamente entre as estações, mas variou segundo os órgãos das plantas, sendo as folhas, o órgão da planta que mais aportou nutrientes. Entretanto, o aporte de nutrientes de cada espécie variou entre as estações e órgãos da planta. A taxa de decomposição medida pela evolução de C-CO2 foi maior para o fedegoso, o mulungu, o ipê-preto e o papagaio e menores para o abacate, o ingá e o açoita-cavalo. Lignina/N e lignina + polifenol/N, foram as relações que melhores correlacionaram com a taxa de decomposição dos materiais das diferentes espécies. Entre as leguminosas, o mulungu e fedegoso tiveram a maior taxa de decomposição, medida utilizando litterbag , e ingá a menor. As maiores porcentagens de fixação biológica de nitrogênio foram verificadas para o mulungu (22,6 %) e ingá (20,6%). Os nutrientes mais rapidamente disponibilizados do resíduo das espécies leguminosas foi o K. Os mais lentos foram o Mg e o Ca. O material aportado pelas espécies possuem características, e também, dinâmicas de decomposição e liberação de nutrientes diferentes. O entendimento destas características e destes processos podem contribuir para desenhar sistemas sistemas agroecológicos familiares conciliando a produtividade e a conservação do solo e da diversidade. Quando usadas de forma diversificada, essas espécies podem contribuir para uma ciclagem de nutrientes constante e equilibrada nestes sistemas. Portanto a diversificação dos sistemas agroflorestais permite a melhor utilização do potencial em ciclar nutrientes das árvores nativas da Mata Atlântica.

Made available in DSpace on 2015-03-26T13:53:33Z (GMT). No. of bitstreams: 1 texto completo.pdf: 497289 bytes, checksum: 2a624d38a4e6bb153489219838996a27 (MD5) Previous issue date: 2006-02-23 / The objective of the work here presented was to evaluate the soil quality, especially the physical and chemical indicators, in agroforestry (AFs) and monoculture systems, in the station of the Cacao Research Center, Alta Floresta/MT. The studied systems were cocoa (Theobroma cacao), gliricídia (Gliricidia sepium) e cumaru (Dipterix adorata); cupuaçu (Theobroma grandiflorum), gliricidia e cumaru; palm (Bactris gassipaes) e; coffee (Coffea canephora Pierre). A near by forest was used as reference. The area of each system was divided in three parts, considered replicate, for the soil sampling, done in three depths 0 - 5 cm, 5 - 20 cm e 20 - 60 cm. In each replicate and in each depth five samples were taken to form one compound sample. The biomass of the trees was calculated using the breast height diameter (bhd). In the soils were analysed the dispersed clay in water, the humidity equivalent, the aggregation stability, the total organic carbon, the total organic matter, the light organic matter, oxidized organic carbon rates, the total soil nitrogen, nitrate, ammonium, soil texture, pH, phosphorus (P, available and remained), potassium (K), calcium (Ca), magnesium (Mg), exchangeable aluminium (Al) and aluminium + hydrogen (Al + H). Based on the oxidized organic carbon rates were calculated the index of carbon management (ICM), using for that the index of carbon compartment (ICC), the labiality of carbon (L) and the index of labiality (IL). The carbon on the biomass was higher than on the monoculture systems, which is an indication of the contribution of the AFs on the climate regulation because they increase the carbon sequestration on the biomass. Most of the characteristic analysed did not show differences, probably because of the age of the systems (four years) and the similarity of the systems (AFs and perennial monocultures), however the higher index of carbon management (ICM) was observed on the cocoa AF. In the cocoa AF was also observed higher percentage of aggregates on the 2,0 to 1,0 mm class, which is associated to the increase of ICM. Therefore, the cocoa AF seems to be more stable and sustainable than the other systems and is a promising system for the sustainable use of the soils in the Amazon region. With time it is expected to have higher levels of soil organic matter and light organic matter, which may to distinguish the cupuaçu AF of the other systems. / O presente trabalho teve por objetivo avaliar a qualidade do solo, em especial no que se refere aos indicadores físicos e químicos, em sistemas agroflorestais (SAFs) e em monocultivo em área experimental do Centro de Pesquisa da Lavoura Cacaueira, Alta Floresta/MT. Os sistemas estudados foram cacau (Theobroma cacao), gliricídia (Gliricidia sepium) e cumaru (Dipterix adorata); cupuaçu (Theobroma grandiflorum), gliricídia e cumaru; pupunha (Bactris gassipaes) e; café conillon (Coffea canephora Pierre). Como testemunha utilizouse uma área de mata localizada próxima aos sistemas mencionados. A área de cada sistema foi dividida em 3 partes, considerada cada parte uma repetição, para amostragem de solo realizada nas profundidades 0 - 5 cm, 5 - 20 cm e 20 - 60 cm. Em cada repetição e em cada profundidade foram coletadas cinco amostras de solo, formando uma amostra composta. Calculou-se a biomassa aérea das árvores tendo como base o diâmetro das mesmas à altura do peito. Nos solos foram determinados os teores de argila dispersa em água, o equivalente de umidade, a estabilidade de agregados, o carbono orgânico total do solo, a matéria orgânica total e leve em água, as frações de carbono orgânico oxidável, o nitrogênio total do solo, o nitrato e o amônio, a granulometria, o pH e os teores de fósforo (P, disponível e remanescente), de potássio (K), de cálcio (Ca), de magnésio (Mg), de alumínio trocável (Al) e de alumínio + hidrogênio (Al+H). Com base no fracionamento do carbono orgânico oxidável foi determinado o índice de manejo do carbono (IMC), para tal determinou-se o índice de compartimento de carbono (ICC), a labilidade do carbono (L) e o índice de labilidade (IL). O carbono imobilizado na biomassa dos SAFs foi muito superior ao carbono imobilizado nos monocultivos, o que aponta os SAFs como possíveis contribuidores na regulação do clima, pois aumentam o seqüestro de carbono pela biomassa. Não houve diferenças em muitas características analisadas o que pode ser atribuído ao pouco tempo de manejo (quatro anos) e a similaridade entre os sistemas estudados (SAFs e monocultivos com culturas perenes), contudo os maiores índices de manejo de carbono (IMC) foram observados nos SAF com cacau. Neste SAF também houve aumento na porcentagem de macro agregados (classe de agregados de 2,0 a 1,0 mm) o que está associado ao aumento do IMC. O SAF com cacau, portanto parece ser mais estável e sustentável do que os demais sistemas e constitui sistema promissor para o uso dos solos no contexto amazônico. Com o tempo espera-se maior aumento dos teores de MOS e MOL o que poderá contribuir para distinguir o sistema com cupuaçu dos sistemas em monocultivo.