Globalmente, o crescimento populacional gera uma maior demanda por energia, atualmente suprida por fontes fósseis. Nesse sentido, políticas públicas têm estimulado as fontes de energias renováveis, como por exemplo a produção de etanol de segunda geração (2G), a partir de materiais celulósicos, como a palha da cana-de-açúcar. Contudo, a remoção dessa palha pode alterar atributos químicos, físicos e biológicos do solo e, por fim, a produtividade da cultura. Portanto, o objetivo deste estudo é avaliar as mudanças ocasionadas pela remoção de quantidades de palha em atributos do solo e os impactos nos componentes de produção da cana-de-açúcar. O experimento foi conduzido próximo a cidade de Igaraçu do Tietê-SP. O solo do local foi classificado como Nitossolo Vermelho Eutróferrico Típico. O delineamento utilizado foi blocos ao acaso com cinco tratamentos e três repetições. Os tratamentos avaliados foram as seguintes quantidades de palha depositadas uniformemente na superfície do solo: 0; 2; 3,2 e 7,5 Mg ha-1 de massa de matéria seca; Adicionalmente, testou-se um tratamento com 7,5 Mg ha-1 de palha aleirada na entrelinha. Foram avaliados atributos químicos, físicos e biológicos do solo tais como, pH, macronutrientes, densidade e resistência à penetração, teor e estoques de carbono e nitrogênio e biomassa microbiana. Para a maioria dos atributos do solo, as camadas avaliadas foram: 0-10; 10-20; 20-30 cm, contudo, as camadas avaliadas para os atributos químicos, ao fim do ciclo, foram: 0-5; 5-10; 10-20; 20-30 cm. Em relação a planta, foram avaliados o número e altura de plantas, aos 7, 15, 30, 45, 60, 90, 180 e 390 dias após o corte (DAC). O índice de área foliar foi determinado aos 120, 150 e 180 DAC. A determinação da produtividade da cultura foi feita por biometria aos 390 DAC. Foi calculado o acúmulo de nutrientes na cultura para os tratamentos 0; 3,2; 7,5 Mg ha-1 ao fim do ciclo. Após um ano de implantação do experimento, as diferentes quantidades de palha não alteraram os atributos químicos, densidade do solo e o teor de estoques de C e N. Por outro lado, a deposição de 7,5 Mg ha-1 de palha reduziu a compactação do solo na entre linha de 150 cm. A deposição de maiores quantidades de palha interferiu na rebrota e perfilhamento inicial da cana-de-açúcar, contudo, com o decorrer do ciclo, as plantas se recuperaram, havendo uma estabilização similar no número e altura de planta entre os tratamentos, acarretando valores de IAF e produtividade similares. Dessa forma, conclui-se que para as condições encontradas neste estudo, a remoção da palha no curto prazo não provocou impactos negativos dos atributos químicos, físico e biológicos e, consequentemente redução na produtividade da cana-de-açúcar. Contudo, destaca-se a necessidade de monitorar os efeitos da remoção de palha de cana-de-açúcar nos atributos do solo e planta por médio e longo prazo, permitindo assim, um melhor entendimento acerca da sustentabilidade desta prática de manejo emergente no Brasil. / Globally, the population growth generates an increasing demand for energy, currently supplied by fossil sources. In this sense, public policies have stimulated the renewable energies sources, such as the production of second-generation ethanol (2G), from cellulosic materials, such as sugarcane straw. However, the straw removal can alter chemical, physical and biological soil properties and, finally, the crop yield. Therefore, the objective of this study was to evaluate the straw removal management effects on soil attributes and its impacts on the sugarcane growth and yield. The experiment was conducted near to Igaraçu do Tietê-SP. The soil was classified as an Oxisol \"Nitossolo Vermelho eutróferrico típico\". The experimental design used was a randomized blocks with five treatments and three replications. The evaluated treatments were the following amounts of straw deposited uniformly on the soil surface: 0; 2; 3.2 and 7.5 Mg ha-1 of dry matter mass. In addition, a treatment with 7.5 Mg ha-1 of straw piled within inter-row was tested. Soil chemical, physical and biological attributes such as pH, macronutrients, bulk density, soil resistance to penetration, carbon and nitrogen contents and stocks and microbial biomass were evaluated. For the majority of soil attributes, the evaluated soil layers were: 0-10; 10-20; 20-30 cm, however, the evaluated layers for the chemical attributes, at the end of the cycle, were: 0-5; 5-10; 10-20; 20-30 cm. In terms of plants, the number and height of plants were evaluated at 7, 15, 30, 45, 60, 90, 180 and 390 days after cutting (DAC). The leaf area index (LAI) was determined at 120, 150 and 180 DAC. The determination of the yield of the culture was performed by biometric analysis at 390 DAC. The plant-accumulation of nutrients was calculated for the treatments 0; 3.2; 7.5 Mg ha-1 at the end of the cycle. After one year of implementation of the experiment, the different amounts of straw did not change the chemical attributes, bulk density and soil C and N stocks. On the other hand, the maintenance of 7.5 Mg ha-1 of straw on soil surface reduced the soil compaction, especially within 150-cm spaced crop rows. The maintanance of larger amounts of straw had negative impacts on regrowth and initial tillering of sugarcane; however, with the course of the cycle, the plants recovered, with a similar stabilization in the number and height of the plant between the treatments, leading to similar values of LAI and stalk yield. In conclusion, for the conditions found in this study, short-term straw removal did not cause negative impacts on chemical, physical and biological attributes and, thus, a reduction in sugarcane yield. However, it is necessary to monitor the effects of the removal of sugarcane straw on soil and plant attributes over the medium and long term towards a better understanding of the sustainability of this emergent management practice in Brazilian sugarcane production.

Submitted by Gabriela Lopes (gmachadolopesufpel@gmail.com) on 2018-02-08T11:02:37Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertaçao Final Rafael Barcellos Nunes.pdf: 1393960 bytes, checksum: f748f562ab1182d19385edfe5b570af6 (MD5) / Approved for entry into archive by Aline Batista (alinehb.ufpel@gmail.com) on 2018-02-16T10:55:13Z (GMT) No. of bitstreams: 2 Dissertaçao Final Rafael Barcellos Nunes.pdf: 1393960 bytes, checksum: f748f562ab1182d19385edfe5b570af6 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2018-02-16T10:55:13Z (GMT). No. of bitstreams: 2 Dissertaçao Final Rafael Barcellos Nunes.pdf: 1393960 bytes, checksum: f748f562ab1182d19385edfe5b570af6 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2017-03-30 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / O tabaco é uma cultura de grande importância econômica no Brasil, sendo esse o segundo produtor mundial. O estado do Rio Grande do Sul é o maior produtor Brasileiro. O município de Pelotas mesmo não caracterizando se como um grande produtor de tabaco, cultura representa uma fonte geradora de renda muito importante. Entretanto, o cultivo de tabaco ocasiona diversos problemas relacionados ao mau uso do solo, haja visto, que o referido cultivo é muito intenso, o que causa muitos desgastes ao solo. O objetivo deste trabalho foi, portanto, construir um diagnóstico da qualidade do solo em áreas submetidas ao cultivo do tabaco, com no mínimo 15 anos de produção contínua, localizadas no município de Pelotas, RS. Para se construir este diagnóstico foram avaliadas, além das áreas com tabaco, áreas adjacentes com vegetação nativa. Para mensurar a qualidade do solo foram selecionados uma cesta de indicadores, contemplando a propriedades físicas, químicas, biológicas e microbiológicas do solo. As quais foram: densidade do solo, porosidade total, microporosidade, macroporosidade, resistência a penetração, diâmetro médio ponderado dos agregados, pH, matéria orgânica, capacidade de troca de cátions, teor de Al e Na, macronutrientes (K, P, Ca, Mg), micronutrientes (Mn, Zn, Cu), relação de ácaros e colêmbolos (mesofauna), minhocas (macrofauna), carbono da biomassa microbiana, respiração basal e quociente metabólico. Os resultados químicos mostram alterações significativas quando comparadas às vegetações nativas, principalmente pela perda de matéria orgânica e menor capacidade de troca de cátions da área cultivada com tabaco. Já os físicos apresentam valores estatisticamente inferiores aos da vegetação nativa, principalmente em relação aos valores de diâmetro médio ponderado. Os indicadores biológicos mostram valores abaixo do recomendado. Por sua vez, os indicadores microbiológicos apresentam valores inferiores para o carbono da biomassa microbiana nas áreas cultivadas. Neste sentido, concluiu se que a produção intensiva de tabaco ocasiona perdas na qualidade do solo como um todo. / Tobacco is a crop of great economic importance in Brazil being this the second largest producer in the world. Rio Grande do Sul is the largest Brazilian producer. The municipality of Pelotas, even though it is not characterized as a major tobacco producer, this crop represents to the municipality a very important source of income. However, the cultivation of tobacco causes several problems related to the soil, since it has been intensively cultivated, which causes many wear to the soil. The objective of this work was, therefore, to construct a soil quality diagnosis in areas submitted to tobacco cultivation, with at least 15 years of continuous production, located in the city of Pelotas, RS. In order to construct this diagnosis, in addition to the areas with tobacco, adjacent areas with native vegetation were evaluated. In order to measure soil quality, a minimum data set of indicators was selected, considering the physical, chemical, biological and microbiological attributes of the soil. Soil density, total porosity, microporosity, macroporosity, penetration resistance, weighted average diameter of the aggregates, pH, organic matter, cation exchange capacity, ontent of Al and Na, macronutrients (K, P, Ca, Mg), micronutrients (Mn, Zn, Cu), mite and collophy (mesofauna) relationship, earthworms (macrofauna), microbial biomass carbon, basal respiration and metabolic quotient. The chemical results showed significant changes when compared to the native vegetation, mainly due to the loss of organic matter and lower cation exchange capacity of the cultivated area with tobacco. On the other hand, the physical indicators presented statistically lower values, mainly to the weighted average diameter and the biological indicators presented values below the recommended one, but without statistical differences between the areas. In turn, the microbiological indicators presented lower values for microbial biomass carbon in the cultivated areas and there was no significant difference in relation to the basal respiration evaluated in the areas. In this sense, it was concluded that the intensive production of tobacco caused losses in the quality of the soil as a whole.

Globalmente, o crescimento populacional gera uma maior demanda por energia, atualmente suprida por fontes fósseis. Nesse sentido, políticas públicas têm estimulado as fontes de energias renováveis, como por exemplo a produção de etanol de segunda geração (2G), a partir de materiais celulósicos, como a palha da cana-de-açúcar. Contudo, a remoção dessa palha pode alterar atributos químicos, físicos e biológicos do solo e, por fim, a produtividade da cultura. Portanto, o objetivo deste estudo é avaliar as mudanças ocasionadas pela remoção de quantidades de palha em atributos do solo e os impactos nos componentes de produção da cana-de-açúcar. O experimento foi conduzido próximo a cidade de Igaraçu do Tietê-SP. O solo do local foi classificado como Nitossolo Vermelho Eutróferrico Típico. O delineamento utilizado foi blocos ao acaso com cinco tratamentos e três repetições. Os tratamentos avaliados foram as seguintes quantidades de palha depositadas uniformemente na superfície do solo: 0; 2; 3,2 e 7,5 Mg ha-1 de massa de matéria seca; Adicionalmente, testou-se um tratamento com 7,5 Mg ha-1 de palha aleirada na entrelinha. Foram avaliados atributos químicos, físicos e biológicos do solo tais como, pH, macronutrientes, densidade e resistência à penetração, teor e estoques de carbono e nitrogênio e biomassa microbiana. Para a maioria dos atributos do solo, as camadas avaliadas foram: 0-10; 10-20; 20-30 cm, contudo, as camadas avaliadas para os atributos químicos, ao fim do ciclo, foram: 0-5; 5-10; 10-20; 20-30 cm. Em relação a planta, foram avaliados o número e altura de plantas, aos 7, 15, 30, 45, 60, 90, 180 e 390 dias após o corte (DAC). O índice de área foliar foi determinado aos 120, 150 e 180 DAC. A determinação da produtividade da cultura foi feita por biometria aos 390 DAC. Foi calculado o acúmulo de nutrientes na cultura para os tratamentos 0; 3,2; 7,5 Mg ha-1 ao fim do ciclo. Após um ano de implantação do experimento, as diferentes quantidades de palha não alteraram os atributos químicos, densidade do solo e o teor de estoques de C e N. Por outro lado, a deposição de 7,5 Mg ha-1 de palha reduziu a compactação do solo na entre linha de 150 cm. A deposição de maiores quantidades de palha interferiu na rebrota e perfilhamento inicial da cana-de-açúcar, contudo, com o decorrer do ciclo, as plantas se recuperaram, havendo uma estabilização similar no número e altura de planta entre os tratamentos, acarretando valores de IAF e produtividade similares. Dessa forma, conclui-se que para as condições encontradas neste estudo, a remoção da palha no curto prazo não provocou impactos negativos dos atributos químicos, físico e biológicos e, consequentemente redução na produtividade da cana-de-açúcar. Contudo, destaca-se a necessidade de monitorar os efeitos da remoção de palha de cana-de-açúcar nos atributos do solo e planta por médio e longo prazo, permitindo assim, um melhor entendimento acerca da sustentabilidade desta prática de manejo emergente no Brasil. / Globally, the population growth generates an increasing demand for energy, currently supplied by fossil sources. In this sense, public policies have stimulated the renewable energies sources, such as the production of second-generation ethanol (2G), from cellulosic materials, such as sugarcane straw. However, the straw removal can alter chemical, physical and biological soil properties and, finally, the crop yield. Therefore, the objective of this study was to evaluate the straw removal management effects on soil attributes and its impacts on the sugarcane growth and yield. The experiment was conducted near to Igaraçu do Tietê-SP. The soil was classified as an Oxisol \"Nitossolo Vermelho eutróferrico típico\". The experimental design used was a randomized blocks with five treatments and three replications. The evaluated treatments were the following amounts of straw deposited uniformly on the soil surface: 0; 2; 3.2 and 7.5 Mg ha-1 of dry matter mass. In addition, a treatment with 7.5 Mg ha-1 of straw piled within inter-row was tested. Soil chemical, physical and biological attributes such as pH, macronutrients, bulk density, soil resistance to penetration, carbon and nitrogen contents and stocks and microbial biomass were evaluated. For the majority of soil attributes, the evaluated soil layers were: 0-10; 10-20; 20-30 cm, however, the evaluated layers for the chemical attributes, at the end of the cycle, were: 0-5; 5-10; 10-20; 20-30 cm. In terms of plants, the number and height of plants were evaluated at 7, 15, 30, 45, 60, 90, 180 and 390 days after cutting (DAC). The leaf area index (LAI) was determined at 120, 150 and 180 DAC. The determination of the yield of the culture was performed by biometric analysis at 390 DAC. The plant-accumulation of nutrients was calculated for the treatments 0; 3.2; 7.5 Mg ha-1 at the end of the cycle. After one year of implementation of the experiment, the different amounts of straw did not change the chemical attributes, bulk density and soil C and N stocks. On the other hand, the maintenance of 7.5 Mg ha-1 of straw on soil surface reduced the soil compaction, especially within 150-cm spaced crop rows. The maintanance of larger amounts of straw had negative impacts on regrowth and initial tillering of sugarcane; however, with the course of the cycle, the plants recovered, with a similar stabilization in the number and height of the plant between the treatments, leading to similar values of LAI and stalk yield. In conclusion, for the conditions found in this study, short-term straw removal did not cause negative impacts on chemical, physical and biological attributes and, thus, a reduction in sugarcane yield. However, it is necessary to monitor the effects of the removal of sugarcane straw on soil and plant attributes over the medium and long term towards a better understanding of the sustainability of this emergent management practice in Brazilian sugarcane production.

Globally, increasing demands for biofuels have intensified the rate of land-use change (LUC) for expansion of bioenergy crops. In Brazil, the world\'s largest sugarcane-ethanol producer, sugarcane area has expanded by 35% (3.2 Mha) in the last decade. Sugarcane expansion has resulted in extensive pastures being subjected to intensive mechanization and large inputs of agrochemicals, which have direct implications on soil quality (SQ). We hypothesized that LUC to support sugarcane expansion leads to overall SQ degradation. To test this hypothesis we conducted a field-study at three sites in the central-southern region, to assess the SQ response to the primary LUC sequence (i.e., native vegetation to pasture to sugarcane) associated to sugarcane expansion in Brazil. At each land use site undisturbed and disturbed soil samples were collected from the 0-10, 10-20 and 20-30 cm depths. Soil chemical and physical attributes were measured through on-farm and laboratory analyses. A dataset of soil biological attributes was also included in this study. Initially, the LUC effects on each individual soil indicator were quantified. Afterward, the LUC effects on overall SQ were assessed using the Soil Management Assessment Framework (SMAF). Furthermore, six SQ indexes (SQI) were developed using approaches with increasing complexity. Our results showed that long-term conversion from native vegetation to extensive pasture led to soil acidification, significant depletion of soil organic carbon (SOC) and macronutrients [especially phosphorus (P)] and severe soil compaction, which creates an unbalanced ratio between water- and air-filled pore space within the soil and increases mechanical resistance to root growth. Conversion from pasture to sugarcane improved soil chemical quality by correcting for acidity and increasing macronutrient levels. Despite those improvements, most of the P added by fertilizer accumulated in less plant-available P forms, confirming the key role of organic P has in providing available P to plants in Brazilian soils. Long-term sugarcane production subsequently led to further SOC depletions. Sugarcane production had slight negative impacts on soil physical attributes compared to pasture land. Although tillage performed for sugarcane planting and replanting alleviates soil compaction, our data suggested that the effects are short-term with persistent, reoccurring soil consolidation that increases erosion risk over time. These soil physical changes, induced by LUC, were detected by quantitative soil physical properties as well as by visual evaluation of soil structure (VESS), an on-farm and user-friendly method for evaluating SQ. The SMAF efficiently detected overall SQ response to LUC and it could be reliably used under Brazilian soil conditions. Furthermore, since all of the SQI values developed in this study were able to rank SQ among land uses. We recommend that simpler and more cost-effective SQI strategies using a small number of carefully chosen soil indicators, such as: pH, P, K, VESS and SOC, and proportional weighting within of each soil sectors (chemical, physical and biological) be used as a protocol for SQ assessments in Brazilian sugarcane areas. The SMAF and SQI scores suggested that long-term conversion from native vegetation to extensive pasture depleted overall SQ, driven by decreases in chemical, physical and biological indicators. In contrast, conversion from pasture to sugarcane had no negative impacts on overall SQ, mainly because chemical improvements offset negative impacts on biological and physical indicators. Therefore, our findings can be used as scientific base by farmers, extension agents and public policy makers to adopt and develop management strategies that sustain and/or improving SQ and the sustainability of sugarcane production in Brazil. / Globalmente, o aumento da demanda de biocombustíveis têm intensificado a taxa de mudança de uso da terra (MUT) para expansão da produção de culturas para fins energéticos. No Brasil, a área de cana-de-açúcar aumentou 35% (3,2 Mha) na última década. A expansão do cultivo de cana-de-açúcar tem resultado em pastagens extensivas sendo submetidas a intensiva mecanização e ao uso de agroquímicos, implicando diretamente na qualidade do solo (QS). A hipótese testada nesse estudo foi que a MUT resulta na degradação da QS. Para tanto foi conduzido um estudo em três locais na região centro-sul, com objetivo de avaliar as modificações na QS devido a principal sequência de MUT (vegetação nativa - pastagem - cana-de-açúcar) associada a expansão do cultivo de cana-de-açúcar no Brasil. Em cada uso da terra, amostras indeformadas e deformadas de solo foram coletadas nas profundidades de 0- 10, 10-20 e 20-30 cm. Os atributos químicos e físicos do solo foram mensurados através de análises laboratoriais e à campo. Dados de atributos biológicos também foram incluídos no estudo. Inicialmente, os efeitos da MUT foram quantificados individualmente para cada um dos atributos do solo, e em seguida as alterações na QS global foram avaliadas através da Soil Management Assessment Framework (SMAF) e de seis índices de QS (IQS), desenvolvidos usando métodos com complexidade crescente. Os resultados demonstraram que a conversão da vegetação nativa em pastagem extensiva resultou na acidificação do solo, redução dos teores de carbono orgânico (COS) e macronutrientes (especialmente P), e severa compactação do solo, desequilibrando a relação entre ar e água e aumentando a resistência mecânica do solo ao crescimento radicular. Conversão da pastagem em cana-de-açúcar melhorou a qualidade química do solo através da correção da acidez e aumento dos macronutrientes. Apesar dessas melhorias, prolongado período de cultivo de cana-de-açúcar reduziu os teores de COS; e a maioria do P adicionado via fertilizantes acumulou em formas menos lábeis, confirmando o importante papel do P orgânico no fornecimento de P disponível às plantas em solos brasileiros. O cultivo de cana-de-açúcar teve impactos negativos nos atributos físicos do solo menos intensos do que aqueles gerados pelo uso com pastagem. Embora o preparo do solo para plantio e reforma da cana-de-açúcar reduziu a compactação do solo, os dados sugeriram que estes efeitos são de curta duração, ocorrendo a reconsolidação do solo e o aumento dos riscos de erosão ao longo do tempo. As alterações físicas do solo induzidas pela MUT foram detectadas tanto por meio de atributos quantitativos quanto por meio de avaliação visual da estrutura do solo (VESS), um método simples e diretamente aplicado no campo. A SMAF detectou eficientemente as alterações na QS devido a MUT. Além disso, todos os IQS desenvolvidos permitiram ranquear corretamente a QS entre os usos da terra. Assim, recomendamos que IQS mais simples e com melhor relação custo-benefício usando poucos indicadores chaves, tais como: pH, P, K, VESS e COS com ponderação proporcional entre os setores do solo (químico, físico e biológico) sejam usados como protocolo para avaliar a QS nas áreas de produção de cana-de-açúcar. Os resultados obtidos usando a SMAF e os IQS sugeriram que a conversão da vegetação nativa em pastagem extensiva reduziu a QS, degradando indicadores químicos, físicos e biológicos. Por outro lado, a conversão de pastagem em cana-de-açúcar não teve impactos na QS global, uma vez que a melhoria dos atributos químicos compensou os impactos negativos nos indicatores físicos e biológicos. Desta forma, esses resultados poderão ser utilizados como base científica pelos produtores, extencionistas e políticos para orientar estratégias de manejo que mantenham e/ou melhorem a QS e consequentemente a sustentabilidade da produção de cana-de-açúcar no Brasil.

Orientador: Admilson Írio Ribeiro / Resumo: Os processos industriais e de urbanização promovidos nas últimas décadas geraram uma grande dualidade, visto que, proporcionaram o desenvolvimento econômico, em contrapartida suas atividades de implantação e operação ocasionaram diversos impactos ambientais negativos, comprometendo funções ecológicas em diferentes ecossistemas. Diante disso, ações voltadas para a recuperação das áreas degradadas consistem em medidas compensatórias para ambientes que perderam a capacidade de resiliência ou que demandem de um longo período para reestabelecimento das funcionalidades ecológicas e da biodiversidade. Dessa maneira, o monitoramento torna-se uma importante estratégia de gestão para avaliar a evolução da recuperação e verificar o quão próximo encontram-se das metas estabelecidas no Plano de Recuperação de Áreas Degradadas. Assim, além de mensurar aplicabilidade das ações e métodos de recuperação adotados o monitoramento das áreas auxilia na identificação de fatores que possam contribuir para a gestão da área, no decorrer do tempo. Durante essa fase, uma das principais necessidades está na escolha dos indicadores ambientais, pois eles são responsáveis por expressar as condições ambientais durante o processo de monitoramento. A utilização de bioindicador ambiental, relacionados com a macrofauna edáfica torna-se útil, tendo em vista sua capacidade e sensibilidade, as ações antrópicas. Dessa forma, essa pesquisa teve como objetivo avaliar a tendência da macrofauna edáfica em diferentes ár... (Resumo completo, clicar acesso eletrônico abaixo) / Mestre

Draining of the Everglades allowed for the expansion of urban and agricultural development, reducing half of the size of the historic Everglades. The detrimental cascading effect on the Everglades ecosystem function is related to the total phosphorus (TP) concentrations of water inflow, the inflow rate and the distance from the discharge point. As Everglades restoration has approached 15 years since the inception of the Comprehensive Everglades Restoration Plan (CERP), there is a need to assess its progress across the ecosystem. Available data from 2004 to 2014 were collected for soils and from 2004 to 2016 for water to understand a decade of trends. Both Geographic Information System (GIS) and statistical data analysis were applied to determine changes in water quality and soil chemistry. Key findings indicate a declining trend in water TP, with mixed results for soil. Higher TP concentrations (>10 µg/L) were prevalent the areas less than 1 km from a canal or water discharge point for both soil and water. The TP in surface water was higher in the wet season compared to the dry season across the EPA possibly associated with hydrologic, climatic or other factors.

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.

Several farming systems, in a region of the Dark Brown soil zone west of Saskatoon, were investigated to identify farming practices that are soil-conserving, or soil-degrading, by measuring their effects on soil quality. The study identified soil properties that are practical and measurable indicators of soil quality, and factors that influence farmers adoption of soil-conserving farming practices. On coarse-loamy to sandy-textured, glaciolacustrine soils, farming systems with long rotations and adequate fertilizer inputs or permanent cover, were associated with a higher quality of soils than tillage-intensive crop-fallow systems. Better soil quality was attributed to the larger addition of crop residues, enabling long-rotation soils to maintain a relatively large pool of mineralizable C, N, and P, and a large microbial biomass. The larger microbial biomass was an indicator of the improved quality of continuously cropped soils as a habitat for microorganisms, and their increased ability to cycle nutrients and C. Other indicators of improved soil quality were increased soil thickness, organic C content, infiltration rate, and aggregation, and decreased bulk density and salinity. Slightly lower A horizon pH was the only negative indicator of quality associated with the continuously cropped soils. The ability of farmers to adapt the longer-rotation systems was constrained by capital and labour limitations, management skills or lifestyle choices. Farmers with limited capital were less willing to invest in the inputs required to continuously crop, because they perceived an increase in the risk of crop failure in that system. Farmers with a large land base, or with off-farm employment, may not have the time or labour to seed and harvest all of their land every year. Among the study farms, the farmers who were best able to adopt continuous cropping systems were those involved in multifamily, mixed farms. There were less labour and capital limitation to continuous cropping on multifamily farms. On mixed farms, where income was derived from both livestock and grains, the risk of reduced grain yield was less serious. Appropriate use of low quality, erodible soils was often an important consideration of farmers who raised cattle.

ABSTRACT SOIL AND WATER ANALYSIS TECHNIQUES FOR AGRICULTURAL PRODUCTION Maral, Nuh M. Sc., Department of Chemistry Supervisor: Prof. Dr. G. inci G&ouml / kmen May 2010, 108 pages In Turkey, usage of increasing amounts of fertilizers and pesticides by some unconscious farmers cause soil pollution and soil infertility for the crop production. Usage of water in excessive amounts and/or in poor quality for irrigation creates problems during the plant production. So in this study, soil and water samples were analyzed by using simple and reliable techniques for the soil and water quality in laboratories of METU and Soil Fertilizer and Water Resources Central Research Institute Laboratory in Ankara. The soil and water samples were collected using the standard techniques from Ankara, Bolu, &Ccedil / orum and Kirikkale. According to the soil test results, the textures of the soil samples are found as loam and clay loam. The total salt content of the soil samples are between 0.033 &ndash / 0.063 % (w/w), meaning they are low salinity soils (total salt less than 0.15 % w/w). The pH of the soil samples are between 7.86&ndash / 8.15, they are slightly alkaline. The phosphorus concentrations of soil samples are in a range 4.95 to 35.45 P2O5 kg/da. Some of the soil samples have too high phosphorus content (greater than 12 P2O5 kg/da). The potassium content of soil samples are found between 141&ndash / 286 K2O kg/da, so the soil is efficient for crop production. Lime content of the soil samples is between 1.04&ndash / 2.67 % (w/w) CaCO3. It means all of the soil samples are calcareous but it is not too high for the agricultural production. Organic matter content of soil samples are found between 0.83&ndash / 2.04 % (w/w). This means the soils are limited in their organic matter content for the crop production. Analysis of 22 water samples yielded EC values between 0.384 &ndash / 1.875 dS/m. Water samples have moderate to high-salinity (if EC values between 0.205 and 2.250 dS/m), yet these can be used for the irrigation of the crops. pH values of water samples are found between 7.18-8.10, meaning that they are slightly alkaline. Bicarbonate concentrations of 19 of the water samples are greater than 200 mg/L. These waters may not be suitable for irrigation of ornamental plants. All of the water samples, except water samples from G&ouml / lbaSi, have sodium absorption ratio (SAR) values between 1 and 9. Water samples with low SAR values, except water samples from G&ouml / lbaSi, can be used for irrigation of almost all soils with little danger of developing harmful levels of sodium. The Residual Sodium Carbonate (RSC) values of water samples Ankara G&ouml / lbaSi and Sincan-1 are greater than 2.50 meq/L and these water samples are not suitable for the irrigation. RSC values of Etimesgut, Sincan-2 and Kazan water samples are positive and lower than the value 2.00 meq /L. All the other water samples have negative RSC values so they are the safe to use for irrigation. It has been observed that development of practical field analysis techniques for all soil and water quality parameters may be possible with exception of micronutrient determination. For determining soil and water quality parameters in the rural areas there is a need to establish a small laboratory with necessary equipment and apparatus and training one or two farmers. With the experience gained in this study, some of these techniques may be adapted to the rural field applications, so soil and water may be tested by the farmers for better yields.

Soil quality standards (SQSs) are one of the most important elements of management system for contaminated sites. In order to manage risks associated with soil contamination, risk based SQSs are used worldwide. However, in Turkey, the Soil Pollution Control Regulation in force was focusing mainly on the use of stabilized sludge on soil and was including standards for a limited number of parameters, mainly metals and some organic chemicals. Thus, existing SQSs were far away from providing common criteria for assessment of the soil quality. In this study, the aim was to develop human health risk based SQSs for Turkey. For derivation of risk based SQSs, the conceptual framework and technical infrastructure were established. SQSs were derived for 151 chemical substances and for three different land use types by incorporating generic site characteristics for Turkey. Since SQSs are highly sensitive to site conditions and chemical-specific data used in calculations, a Microsoft Excel based exposure model was developed as a technical tool. This tool serves for calculation of generic and site-specific SQSs and maintenance of the currency of the standards by allowing periodic update of data used in calculations. Besides, a hydrogeologic database was developed to provide information on the general soil and hydrogeologic characteristics that are used in derivation of SQSs. This database is ultimately, expected to serve for development of conceptual site models, sampling strategies, and derivation of dilution factors during risk assessment studies. As a result, this study presents a general perspective and approach for derivation of human health risk based SQSs. It is believed that the developed conceptual and technical infrastructure will contribute to contaminated site management and risk assessment studies conducted by the regulatory authorities and the other stakeholders in Turkey.