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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
81

The Effects of Biochar and Anaerobic Digester Effluent on Soil Quality and Crop Growth in Karnataka, India

Sekar, Samantha 29 August 2012 (has links)
No description available.
82

Loblolly Pine and Soil-Site Responses to Harvesting Disturbance and Site Preparation at Stand Closure

Eisenbies, Mark Hale 12 July 2004 (has links)
Intensively managed forests of the Southern United States are among the most important sources of wood fiber and timber in this country. There is a great deal of concern that disturbances associated with trafficking by heavy machinery might diminish long-term soil-site productivity. However, determining the effect of harvesting disturbance and silvicultural treatments on the long-term productivity of pine plantations is difficult because, in addition to harvesting effects, growth distributions are affected by changes in climate, silviculture, and genetics. The primary objectives of this study were to determine (1) whether logging disturbances under operationally realistic circumstances affect soil quality, hydrologic function, and loblolly pine (Pinus taeda L.) productivity on wet pine flats, and (2) whether intensive forest management practices mitigate disturbance effects if they exist. Three 20-ha loblolly pine plantations located on wet pine flats in South Carolina were subjected to combinations of wet- and dry-weather harvesting and mechanical site preparations. Changes in soil-site productivity after five years were evaluated using a new rank method. The key advantage of the rank change method is that it is largely independent of the confounding factors (e.g. genetics, silvicultural practices, and climate) that affect comparisons of tree growth and soil quality between growth cycles. After five years, loblolly pine site indexes (base age 25) ranged between 13 and 33 m, and production ranged between 0.5 and 95 Mg ha-1. Soil bulk densities increased from 1.15 to as high as 1.44 g cm-3 after harvesting; by age 7 years it had decreased to approximately 1.25 g cm-3. At the sub-stand scale (0.008 ha), visually assessed soil physical and harvesting residue disturbances had little influence on relative changes in soil-site productivity after five years. Factors that specifically reflect site drainage were the most influential on changes in productivity. At the operational scale (3.3 ha), there were no differences between wet- and dry- harvested sites as long as bedding was applied as a site treatment. These results indicate that when standard site preparation is employed, fertile, wet pine flats such as these are resilient in that they recover from severe, but operationally realistic, harvesting disturbances. / Ph. D.
83

Soil Organic Matter Dynamics in Cropping Systems of Virginia's Valley Region

Sequeira, Cleiton Henrique 17 March 2011 (has links)
Soil organic matter (SOM) is a well known indicator of soil quality due to its direct influence on soil properties such as structure, soil stability, water availability, cation exchange capacity, nutrient cycling, and pH buffering and amelioration. Study sites were selected in the Valley region of Virginia with the study objectives to: i) compare the efficiency of density solutions used in recovering free-light fraction (FLF) organic matter; ii) compare different soil organic fractions as sensitive indices of short-term changes in SOM due to management practices; iii) investigate on-farm effects of tillage management on soil organic carbon (SOC) and soil organic nitrogen (SON) stocks; and iv) evaluate the role of SOM in controlling soil available nitrogen (N) for corn uptake. The efficiency of the density solutions sodium iodide (NaI) and sodium polytungstate (SPT) in recovering FLF was the same at densities of 1.6 and 1.8 g cm⁻³, with both chemicals presenting less variability at 1.8 g cm⁻³. The sensitivity of SOM fractions in response to crop and soil management depended on the variable tested with particulate organic matter (POM) being the most sensitive when only tillage was tested, and FLF being the most sensitive when crop rotation and cover crop management were added. The on-farm investigation of tillage management on stocks of SOC and total soil N (TSN) indicated significant increases at 0–15 cm depth by increasing the duration (0 to 10 years) of no-tillage (NT) management (0.59 ± 0.14 Mg C ha⁻¹ yr⁻¹ and 0.05 ± 0.02 Mg N ha⁻¹ yr⁻¹). However, duration of NT had no significant effect on SOC and TSN stocks at 0–60 cm depth. Soil available N as controlled by SOM was modeled using corn (<i>Zea mays</i> L.) plant uptake as response and several soil N fractions as explanatory variables. The final model developed for 0–30 cm depth had 6 regressors representing the different SOM pools (active, intermediate, and stable) and a 𝑅² value of 65%. In summary, this study provides information about on-farm management affects on SOM levels; measurement of such effects in the short-term; and estimation of soil available N as related to different soil organic fractions. / Ph. D.
84

[pt] O EFEITO DO BIOCARVÃO NAS CARACTERÍSTICAS QUÍMICAS E NA RETENÇÃO DE ÁGUA DO SOLO SOB UM COQUEIRAL NO MUNICÍPIO DE SEROPÉDICA, RIO DE JANEIRO / [en] THE EFFECT OF BIOCHAR ON THE CHEMICAL CHARACTERISTICS AND WATER RETENTION OF SOIL UNDER A COCONUT PLANTATION IN SEROPÉDICA, RIO DE JANEIRO

MARCELO AURELIO PEREIRA DA SILVA 10 March 2020 (has links)
[pt] A exploração do ecossistema pelo homem tem provocado mudanças ambientais na Terra, como liberação de gases poluentes, aumento da temperatura do planeta, desmatamento, degradação do solo, entre outros. Têm se elaborado novas técnicas que buscam melhorar a qualidade química e física do solo, a recuperação da biodiversidade e ainda contribuir para diminuir os efeitos das mudanças climáticas. O biocarvão é produzido a partir de pirólise de resíduos orgânicos, que pode ser aplicado ao solo para melhorar a qualidade, além de ser uma técnica de mitigação do efeito estufa. O objetivo desse trabalho foi avaliar o efeito da aplicação do biocarvão, produzido de Gliricidia, nos parâmetros físico e químicos do solo em Seropédica, no período de julho de 2017 a julho de 2018. O biocarvão foi incorporado ao Planossolo Háplico sob um coqueiral. O delineamento do experimento utilizado foi em blocos casualizados em esquema fatorial, sendo os fatores com e sem aplicação de biocarvão (10 t ha-1), com 12 repetições em cada tratamento. O biocarvão foi aplicado em faixa de 80 cm, na projeção da copa dos coqueiros. Foram determinados pH, P, Ca, Mg, Al, H+Al, K, Na, Cu, COT, M.O, nas profundidades 0-5, 5-10, 10-20cm, no intervalo de três meses, durante o período de um ano. A propriedade física do solo analisada foi a retenção de água nas potências 0, 60, 100, 330 e 1500 kPa. O uso do biocarvão como condicionador do solo não aumentou significativamente o pH, retenção de água e nos teores de carbono orgânico total e na CTC. Contudo nota-se que o biocarvão pode ser promissor para aumentar o carbono do solo e consequentemente mitigar o efeito estufa. / [en] Ecosystem exploration by humans has led to environmental changes on Earth, such as the release of polluting gases, rising global temperatures, deforestation, soil degradation, and so on. New techniques have been developed that seek to improve the chemical and physical quality of the soil, the recovery of biodiversity and also contribute to reduce the effects of climate change. Biocarbon is produced from pyrolysis of organic waste, which can be applied to the soil to improve the quality, besides being a greenhouse mitigation technique. The objective of this work was to evaluate the effect of biochar, produced of Gliricidia, on the physical and chemical quality of the soil in Seropédica, from July 2017 to July 2018. The biochar was incorporated to the Solonetz under a coqueiral in Seropédica. The experimental design was a randomized complete block design in a factorial scheme, with the factors with and without application of biochar (10 t ha-1), with 12 replicates in each treatment. pH, P, Ca, Mg, Al + 3, H + Al, K, Na, Cu, COT, M.O at depths 0-5, 5-10, 10-20cm were evaluated at three months intervals. The soil physical property analyzed was the water retention at powers 0, 60, 100, 330 and 1500 kPa. The use of bio-carbon as a soil conditioner increased the water retention and total organic carbon contents in the 0-5 cm depth, increasing the organic matter content. The use of biochar as a soil conditioner did not significantly increase pH, water retention and total organic carbon content and CTC. However, it is noted that biochar can be promising to increase soil carbon and consequently mitigate the greenhouse effect.
85

Soil health and quality concept in agricultural extension and soil science : an assessment of topsoil conditions in a long term vineyard soil management trail in Robertson, South Africa

Mathys, Ilse Lois 03 1900 (has links)
Thesis (MScAgric (Soil Science))--University of Stellenbosch, 2011. / Includes bibliography. / ENGLISH ABSTRACT: The natural resource condition or health has been accepted as a valuable indicator of sustainable land use. The assessment of soil health (quality) has become a valuable tool in determining the sustainability of land management systems. This work aims to evaluate the sustainability of soil management practices in agricultural extension for vineyards in Robertson, South Africa based, on the current approach of the concept of soil health and soil quality, as well as to briefly explore the present reservations regarding the definition of the concept. The soil management treatments include a mechanical weed control, chemical weed control, annual addition of straw mulch, annual cover crop and perennial cover crop. The objective of study is to (i) identify suitable soil health (quality) indicators for vineyards in the study area; (ii) analyze the soil health (quality) indicators for different soil management treatments; (iii) evaluate the effect of various soil management treatments on the overall soil functionality, by comparing measured indicators to the soil property threshold values, for optimal vine growth; iv) establish a more consistent understanding and use of the terms health and quality, as understood and used in the general science community, with particular reference to the public health system. The soil physical, chemical and biological properties which were selected as indicators of soil health (quality) based on specific criteria similar to previous work done on the concept. The properties selected include soil texture, gravimetric water content, bulk density, soil aeration, water aggregate stability, soil pH, EC, available N,P,K , soil organic matter content, soil microbial biomass, potential mineralizable nitrogen and soil respiration. The study makes use of methods of analysis previously used for soil health and soil quality assessments, as well as soil analytical methods as accepted by experienced soil scientist within the study area. The soil was sampled on three separate events to depths of 0-200 mm for initial characterization of soil and 0-50 mm to compare soil health (quality) Between tracks and In tracks of treatment plots. The values obtained for each property were compared with the optimum for vineyards and ranked accordingly. The treatment that resulted in the most desirable soil health (quality) was the straw mulch and perennial cover crop treatments. / AFRIKAANSE OPSOMMING: Die toestand of gesondheid van natuurlike hulpbronne is aanvaar as `n waardevolle aanduiding van volhoubare grondgebruik. Die assessering van grond gesondheid (kwaliteit) is 'n waardevolle hulpmiddel in die bepaling van die volhoubaarheid van grond bestuur stelsels. Hierdie werkstuk poog om die volhoubaarheid van grond bestuurs praktyke te evalueer vir wingerde in Robertson, Suid-Afrika wat baseer is op die huidige benadering van grond gesondheid en kwaliteit. Die tesis dek ook die huidige onsekerhede oor die konsep en definisies van terme wat gebruik word in die konsep. Die grond bestuur praktyke sluit in 'n meganiese onkruidbeheer, chemiese onkruidbeheer, jaarlikse toevoeging van `n strooi deklaag, jaarlikse en meerjarige dekgewas dekgewasse. Die doel van die studie was om (i) die geskikte grond gesondheid (kwaliteit) indikators vir wingerde in die studie area te identifiseer, (ii) die grond gesondheid (kwaliteit) indikators vir verskillende bogrond bestuur praktyke te identifiseer; (iii) die effek van verskillende grond bestuur praktyke op die algehele grond funksies te evalueer, deur dit te vergelyk met die gemete indikators vir drempelwaardes vir optimale wingerd groei; iv) 'n meer konsekwente begrip en gebruik van die terme “gesondheid” en “kwaliteit” vas te stel, soos dit verstaan en gebruik word in die algemene wetenskaplike gemeenskap, met spesifieke verwysing na die openbare gesondheidsisteem. Die grond fisiese, chemiese en biologiese eienskappe wat as indikators van grond gesondheid (kwaliteit) geselekteer was, word gebaseer op spesifieke kriteria soortgelyk aan dié wat in vorige werk op die konsep gedoen was. Die eienskappe wat geselekteer is sluit in grondtekstuur, gravimetriese waterinhoud, bulk digtheid, grond deurlugting, totalle water stabiliteit, grond pH, electriese geleiding, toeganklike N, P, K, grond organiese materiaal inhoud, grond mikrobiese massa, potensiële mineraliseerbare stikstof en grond respirasie. Die studie maak gebruik van analitiese metodes wat voorheen gebruik was vir grond gesondheid en kwaliteit, sowel as die grond analitiese metodes soos gebruik deur ervare grondkundiges binne die studie gebied. Die grondmonsters was geneem op drie afsonderlike geleenthede oor dieptes van 0-200 mm vir die aanvanklike karakterisering van grond en 0-50 mm, om grond gesondheid (kwaliteit) Tussen trekkerspore en In trekkerspore van die persele te vergelyk. Die waardes verkry vir elke eienskap was vergelyk met die optimum vir wingerde en verdeel volgens kwaliteit. Die behandeling wat die mees optimale grond gesondheid (kwaliteit) getoon het, was die strooi deklaag en meerjarige dekgewas behandelings.
86

Effects of dyeing and bleaching industries on the area around the Orathupalayam Dam in Southern India

Furn, Kristina January 2004 (has links)
<p>Rural people around the 4 km2 Orathupalayam Dam in southern India live in one of India’s most polluted areas. The people were once restricted mainly by scarcity of water but today they cannot drink their well water or cultivate their soil. The dam, created to store floodwater from the Noyyal River, also stores effluent water from the more than 700 dyeing and bleaching industries situated in the town of Tiruppur, 20 km upstream. Although most industries have treatment plants they do not treat total dissolved solids (TDS) and thus NaCl becomes one of the major components of the effluent. 75 to 100 million litres of effluents are released every day.</p><p>Through water sampling in open and bore wells, and with the help of GPS, ArcView and Surfer it could be concluded that high TDS levels and concentrations of Cl-, Ca2+, Mg2+ and Na+ were associated with the dam. A definite spatial pattern of the spreading of polluted water could be determined. Water from the dam was fed to the ground water all around the dam and also affected the groundwater more than 4 km to the southeast. Soil samples and interviews with farmers made it clear that land irrigated with dam water or affected well water soon became uncultivable. The water destroyed the soil structure and seeds did not germinate after irrigation with polluted water.</p><p>Through interviews it could be concluded that the local people around the dam paid a large part of the externalities of the polluting activities of the textile industries in terms of negative health effects and lost agricultural land, water resources, fishing and working opportunities. These problems have mostly been caused by the high salt concentration in the effluents but it is unclear to what extent other substances have caused or might cause harmful effects to the environment, people and animals.</p>
87

Evaluation of selected soil properties in semi-arid communal rangelands in the Western Bophirima district, South Africa / Abdoulaye Saley Moussa

Saley Moussa, Abdoulaye January 2007 (has links)
Concerns were raised over the past decades, on the degradation condition of arid and semi-arid rangelands in South Africa, mainly in areas under communal land management. Baseline information on soil quality is essential to monitor changes in land conditions and assess impacts of land uses and management over time. The objectives of this study, initiated within the framework of the Desert Margins Program, were to characterize and establish baseline indicators of soil quality health, and to investigate the potential effects of grazing and exclusion management (hypothesized as grazing effect) on selected soil properties in the western Bophirima District in South Africa. Soils were characterized for physical, chemical, enzymatic activity and microbial biomass properties, and grazing effects were evaluated on selected properties. The aboveground herbaceous species composition and biomass production were also determined. Sandy, poor fertile soils (low organic carbon and phosphorus) characterized all sites. Various levels of enzymatic and microbial biomass were recorded at the sites. Grazing had no significant effects on most of soil chemical properties, but did affect selected enzymatic activities, site-specifically. No significant differences of grazing effects were observed on soil microbial biomass. The inconsistent responses of soil properties across the sites prompt to caution regarding the generalization and/or extrapolation of grazing effects to other areas, without consideration of the prevailing environmental and management characteristics to each site. Notwithstanding the alarming plea about degradation at these communal sites, indicators of soil quality did not significantly differ between communal and surrounding commercial and/or game managed areas, despite their apparent vegetation degradation. The results showed that rangeland under the communal management were characterized by increaser species of low grazing value, but this situation did not necessarily interpret severe soil degradation as tacitly described. Soil degradation depends on land use, management and environmental conditions, and references are needed to assess degradation. Important interrelationships between the aboveground vegetation and soil belowground activity were observed. This emphasized the need to integrate both soil and vegetation into rangeland monitoring, as these interrelationships and associated ecological processes sustain rangeland health. Further research is needed to re-examine the "inferred degradation of rangelands in communal areas, taking into consideration their history, and using appropriate baselines and references sites. Only then, can degradation trends and hotspots be identified and thereof, appropriate management decisions (through participatory research) taken locally to combat degradation and sustain long-term rangeland resources uses. / Thesis (Ph.D. (Environmental Science))--North-West University, Potchefstroom Campus, 2007.
88

A new integrative and operational framework to assess the impact of land management on soil quality : From a field scale to a global scale indicator to be integrated within the Life Cycle Assessment framework / Nouveau cadre d’analyse intégré et opérationnel pour évaluer l’impact de l’usage des terres sur la qualité des sols : Définition d’un nouvel indicateur à une échelle locale et à une échelle globale, adapté au cadre d’Analyse du Cycle de Vie

Thoumazeau, Alexis 05 November 2018 (has links)
Le sol fait face à de nombreuses pressions anthropiques qui menacent son fonctionnement et sa capacité à fournir des services essentiels au bien-être humain. Pour évaluer l’effet de ces perturbations et proposer de nouvelles voies de gestion des sols, il est nécessaire de développer des méthodes d’évaluation de la qualité des sols opérationnelles. La qualité des sols a été définie comme « la capacité des sols à fonctionner […] » (Karlen et al., 1997). Cependant, la littérature scientifique se focalise plutôt sur son état et ses propriétés que sur son fonctionnement. En effet, la qualité des sols est généralement appréhendée comme une somme de propriétés édaphiques, chimiques et biologiques qui ne tiennent pas compte des nombreuses interactions de cet écosystème. Cette étude propose un nouveau cadre conceptuel d’évaluation fonctionnelle de la qualité des sols basé sur la mesure directe des fonctions portées par les assemblages biologiques du sol. A partir de ce cadre, un nouveau set d’indicateurs, nommé Biofunctool®, a été développé. Biofunctool® permet de renseigner trois fonctions du sol (transformation du carbone, cycle des nutriments et maintenance de la structure) à partir de douze indicateurs, bords de champ et de faible technicité. Le set d’indicateurs a été appliqué dans divers sites expérimentaux en Asie du Sud Est et a permis de relever l’impact i) de la transition entre une culture annuelle et une culture pérenne, ii) de l’évolution du développement de cultures pérennes et iii) d’une couverture du sol avec légumineuses en plantation d’hévéa sur la qualité des sols. L’évaluation locale et fonctionnelle de la qualité des sols a pu ensuite être extrapolée à une échelle plus globale grâce à un modèle prédictif. Ce modèle permet de répondre à une forte attente d’intégration d’un indicateur fonctionnel de qualité des sols dans les modèles d’évaluation environnementale à une échelle globale comme l’Analyse Cycle de Vie. / Soils are currently threatened by many human activities that jeopardize soil functioning and its ability to provide ecosystem services, vital for human well-being. In order to assess human impacts and to propose new management practices to protect soils, it is necessary to implement assessments of soil quality. Soil quality was defined by Karlen et al. (1997) as “the capacity of soil to function […]”. However, in the literature, most of study focus on assessment of soil properties and intrinsic states rather than focusing on the soil functioning and the multiple interactions within the complex system. This study proposes a new integrative approach of the soil quality from direct assessment of the functions carried out by the soil biological assemblages, namely Biofunctool®. Biofunctool® allows for assessing three soil functions (carbon transformation, nutrient cycling, structure maintenance) based on twelve functional, in-field and low-tech indicators. Biofunctool® was applied over several case studies in Thailand to assess the impact of various land management on soil quality. The results pinpointed the impact of the conversion from an annual cropping system to a perennial one on soil; it also raised the evolution of soil quality over perennial tree stands and the impact of cover crop in rubber tree systems. The local assessment of soil integrative quality was then scaled up, to be integrated within the Life Cycle Assessment framework through a predictive model approach. The model developed allows to meet the current demand in defining integrative indicators of soil quality adapted to global scale environmental frameworks.
89

Sugarcane straw removal for bioenergy production: implications on plant and soil responses / Remoção da palha de cana-de-açúcar para bioenergia: implicações na planta e respostas do solo

Lisboa, Izaias Pinheiro 28 September 2018 (has links)
The usage of crop residues, among other lignocellulosic biomass, has being considered a promising alternative feedstock for bioenergy (i.e., second generation ethanol - ethanol 2G and bioelectricity) production. With the adoption of sugarcane-mechanical harvesting in Brazil, in average 15 Mg ha-1 of straw are left on the field annually. Partial straw removal for bioenergy production has become a common practice, while partial straw retention on the field ensures several benefits for the soil-plant system. Efforts have being done in order to establish the best route to straw recovery from the field and defining the amount which meeting both needs. Thus, the aims of this study were: i) to establish a step-by-step guidelines to straw recovery from the field; ii) to determine the implications of increasing rates of straw removal on plant growth, stalk yield and stalk industrial quality; iii) to evaluate the effectiveness of straw-blanket raking practice on plant growth and yield, and iv) to use Soil Management Assessment Framework (SMAF) as a tool to perform an integrated approach of soil quality (SQ) under different rates of straw removal. To achieve the proposed goals, a 2-years experiment was set up within the dry and wet seasons at Valparaíso and Capivari, São Paulo, locations with different edaphoclimatic conditions. Increases of primary extractor fan\'s velocity on the harvester lead to placement and removal of straw rates proportionally to 0, 25, 50, 75 e 100%. After two years, parameters associated to the soil- chemical [(Phosphorus-P, Potassium-K and pH), physical-(bulk density) and biological- (microbial biomass carbon-MBC and SOC)] attributes were analyzed within the 0-5, 5-10, 10-20 and 20-30 cm. Under colder climatic condition, plant tillering improved by the increasing rates of straw removal, however plant growth and stalk yield are slightly affected by the straw management. Stalk harvested in the dry season presented higher industrial quality than those harvested within the wet season but this parameter is unaffected by straw removal. Further, under colder climatic condition, to rake the straw blanket enhanced plant tillering while plant growth and stalk yield were not influenced by raking the straw blanket. No straw removal increases P content on plant tissue, regardless of blanket management, especially under the poorest inherent soil condition. The SMAF tool was able to detect changes on soil quality under different rates of straw removal and Oxisol responds faster to straw removal management than Ultisol in the short term. Total straw removal leaded to Oxisoil physical quality degradation; among the soil attributes, soil-physical attribute within the 0-10 cm is correlated with stalk yield. The partial straw removal for bioenergy production leads to the optimization on sugarcane biomass usage. However, the appropriate rate of straw to be removed is site specific and ranged 4-9 Mg ha-1 under the conditions in which this study was performed. The stalk yield was unaffected by raking the straw blanket. The monitoring of SOC, adoption of traffic controller and application of subproducts from the sugarcane industry are strategies to increase soil quality and, consequently, the sustainability of the crop cultivation. / O uso de resíduos culturais, dentre outros tipos de biomassa lignocelulósica, tem sido considerado uma alternativa promissora para produção de bioenergia (etanol de segunda geração e bioeletricidade). Com a implementação da colheita mecanizada da cana-de-açúcar no Brasil, em média 15 Mg ha-1 palha são deixadas no campo anualmente. A utilização de parte deste resíduo para produção de bioenergia tem se tornado uma prática comum, enquanto a manutenção de parte da palha no campo viabiliza vários benefícios ao sistema solo-planta. Esforços têm sido feitos a fim de estabelecer a melhor rota para remoção da palha do campo e definir a quantidade que atenda ambas demandas. Assim, os objetivos deste estudo foram: i) estabelecer um guia que viabilize a remoção de diferentes taxas de palha; ii) determinar as implicações oriundas da remoção de taxas de palha no crescimento, produtividade e qualidade tecnológica de colmos; iii) avaliar a eficácia do enleiramento da camada de palha sobre o crescimento e produtividade da cultura e, iv) utilizar Soil Management Assessment Framework (SMAF) como ferramenta para avaliar de modo integrado os efeitos da remoção de diferentes taxas de remoção de palha sobre a qualidade do solo (QS). Para tanto, foram conduzidos quatro ensaios, sendo um na estação seca e outro na estação úmida em dois locais: Capivarí e Valparaíso, SP; locais com diferentes condições edafoclimáticas. Crescentes rotações no extrator primário da colhedora viabilizaram a deposição e remoção de taxas de palha proporcionais a 0, 25, 50, 75 e 100%. Após dois anos, análises de parâmetros associados aos atributos químicos [(P, K, pH), físicos (densidade) e biológicos (carbono da biomassa microbiana - MBC e SOC)] do solo foram realizadas nas profundidades 0- 5, 5-10, 10-20 e 20-30 cm. Em condições climática mais fria, a remoção de crescentes quantidades de palha melhora o perfilhamento da cultura; entretanto, o crescimento e produtividade de colmo são pouco afetadas pelo manejo da palha. A qualidade tecnológica de colmos colhidos na época seca é superior aos colhidos na época úmida, entretanto, este parâmetro não é afetado pela remoção de crescentes quantidades de palha. Sobre condições climática mais fria, o perfilhamento é beneficiado pelo enleiramento da palha, ao passo que tanto o crescimento quanto a produtividade são insensíveis à essa prática. A retenção da palha aumenta o conteúdo de P no tecido vegetal, especialmente em solo naturalmente pouco fértil. A SMAF foi capaz de detectar alterações na QS em função da remoção de taxas de palha; sendo o Latossolo Vermelho distrófico típico o mais afetado pela remoção da palha em relação ao Argissolo Vermelho- Amarelo distrófico típico em curto prazo. A remoção total da palha promoveu degradação física do primeiro tipo de solo; dentre os atributos do solo avaliados, o atributo físico na profundidade 0-10 cm está correlacionado com a produtividade da cultura. A remoção parcial da palha de canade- açúcar para produção de bioenergia promove otimização no uso da biomassa da cultura. Entretanto, a taxa de palha a ser removida é intrínseca para cada local e variou de 4-9 Mg ha-1 neste estudo. A produtividade é insensível ao enleiramento da palha. O monitoramento nos teores de carbono do solo, a adoção do controle de tráfego de máquinas e a aplicação de resíduos da agroindústria canavieira podem ser estratégias adotadas para melhorar a QS e, por consequência, a sustentabilidade de cultivo da cana-de-açúcar.
90

Avaliação do potencial de poluição no solo e nas águas subterrâneas decorrente da atividade cemiterial / Assessment of contamination potential in soil and groundwater due to cemetery activity

Campos, Ana Paula Silva 05 July 2007 (has links)
Em boa parte da sociedade ocidental a morte é vista como um evento perturbador e marcante, apesar disto o tema tem inspirado uma série de publicações. Por outro lado, a atividade cemiterial, tópico também marcante e perturbador, e que pode vir a causar possíveis danos ao meio ambiente e à saúde pública, tem muito pouco material publicado. No que concerne ao meio ambiente e à saúde pública, os cemitérios podem apresentar a potencialidade de comprometer a qualidade do solo e das águas subterrâneas, face ao processo de decomposição dos corpos dispostos no subsolo. Os cemitérios implantados podem vir a constituir-se numa fonte com risco de contaminação, e causar alterações físicas, químicas e biológicas nos locais que não estiverem protegidos ou em condições geológicas vulneráveis. Para minimizar o risco de infiltrações e a contaminação das águas subterrâneas é recomendável manter estanque a base das sepulturas e a utilização de locais com aqüíferos a grandes profundidades. Em condições favoráveis, a carga patogênica associada poderá ser eliminada pelo processo de autodepuração biológica e físico-química do solo. É importante a conscientização da população, com vistas à proteção, limpeza e desinfecção da água de poços, além de cuidados por parte dos cemitérios, no sentido de conhecer a qualidade do lençol freático e sua potabilidade, que devem conduzir monitoramento hidrogeológico periódico. Deve-se manter licenciamento, fiscalização, monitoramento e acompanhamento rigorosos. A implantação e a operação de cemitérios devem ser conduzidas com as melhores técnicas de proteção e preservação do meio ambiente, com amplos estudos ambientais prévios e um alto padrão de operação, respeitando as condições sanitárias estabelecidas e fixando faixas de proteção como forma de garantir a qualidade das águas e seu uso para abastecimento público. O risco potencial de poluição pelos cemitérios pode existir, porém se a implantação e o gerenciamento forem adequados, este poderá ser mínimo, se comparado ao potencial poluidor de outras atividades antrópicas. / In the western society death is seen as a disturbing and marked event, even so this issue has inspired several papers about. In the other hand, cemetery activity that are also a marked and disturbing issue and beside that can cause possible damages to the environment and public health, have inspired few papers about. Concerning the environment and public health, the cemeteries present a potential on damaging soil and groundwater quality due to the decomposition process of the bodies buried in the subsoil. The existing cemeteries can be a high risk source of contamination, and can cause also physical, chemical and biological alterations in the soil and groundwater without protection or with vulnerable conditions. In order to minimize the infiltration risk and the groundwater contamination it is recommendable to keep sealed the bottom of the grave and make use of site with a very deep of water table level. In favorable conditions, the pathogenic associated load can be eliminated by the biological and physical-chemical self-purification process of the soil. It is important the population conscientiousness, viewing water wells cleanness, protection and the prevention of any infection, and beside that, the cemeteries owners in order to know the groundwater quality, they must perform periodical hydrogeological monitoring. It must be kept rigorous processes of permitting, inspection, compliance and monitoring. The construction and operation of cemeteries must be conducted using the best techniques for the environmental protection and conservation, and after an extensive previous environmental studies and an high standard operation, in compliance with all sanitary requirements and setting protection zones as one of the way to protect the water quality and its use as a public water supply. The potential risk of pollution from the cemeteries exists, but if the implementation and the management are adequate, the risk could be minimized, even comparing to the polluter potential of other anthropic activities.

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