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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.
11

FERTILIDADE DE SOLO E VIABILIDADE TÉCNICA ECONÕMICA DA AGRICULTURA DE PRECISÃO NA REGIÃO DAS MISSÕES RS. / SOIL FERTILITY AND TECHNICAL FEASIBILITY - ECONOMIC OF PRECISION AGRICULTURE IN THE REGION OF MISSIONS RS.

Schadeck, Flavio André 30 January 2015 (has links)
This paper presents a study that was conducted in a commercial area of grain production in the municipality of Santo Ângelo, region of the Missions - northwest of Rio Grande do Sul, during the Master Course in Precision Agriculture, Federal University Santa Maria / UFSM. The Climate is second Köppen classification of humid subtropical Cfa and gently undulating, with a fertility for the nutrient phosphorus (P) already built. This study aimed to determine whether use of precision agriculture tools, by applying fertilizers correction broadcasted with the variable rate shows an increase in soil fertility levels, and to verify the yield of soybean and wheat over three years subsequent and its technical and economic viability. The Trial period was set for the months of June 2011 to June 2014. Methodologically the project had an applied research, quantitative nature, from the point of view of its objectives was contemplating a descriptive case study. technical and economic. The Soil analyzes were performed by BaseAP Company, highlighting the main variables pH soil, Saturation for bases and potassium with need correction. Obtained was a 43% reduction in the use of lime and an increase in soybean and wheat productivity between 19 and 28%. The study showed an economic return to the producer of 22% compared to a control area without Precision Agriculture. It was expected an increase in the potassium concentration in the resampling but not found, raising the possibility of doing a maintenance fertilization on crop instead of making a soil amendment. / Este trabalho apresenta um estudo que foi realizado em uma área comercial de produção de grãos, no Município de Santo Ângelo, região das Missões - Noroeste do Rio Grande do Sul, durante a conclusão do curso de Pós-Graduação em Agricultura de Precisão pela Universidade Federal de Santa Maria/UFSM. O clima da região é segundo classificação de Köppen-Geiger do tipo Cfa subtropical úmido e o relevo levemente ondulado, com uma fertilidade para o nutriente fósforo (P) já construída. Esse trabalho teve como objetivo verificar se o uso de ferramentas de Agricultura de Precisão, pela aplicação de correção de fertilizantes a lanço e a taxa variada apresenta um aumento nos teores de fertilidade solo, verificando também as produtividades de soja e trigo ao longo de três anos subsequentes e sua viabilidade técnica e econômica. O período do experimento foi definido para os meses de junho de 2011 a junho de 2014. Metodologicamente o projeto teve uma pesquisa aplicada, de cunho quantitativo, do ponto de vista de seus objetivos foi descritiva contemplando um estudo de caso. As análises de solo foram realizadas pela Empresa BaseAP, destacando-se como variáveis principais pH do solo, Saturação por bases e Potássio que apresentaram necessidade de correção. Obteve-se uma redução de 43% no uso de calcário dolomítico e um aumento de produtividade de soja e trigo entre 19 e 28%. O estudo mostrou um retorno econômico ao produtor de 22% comparado a uma área testemunha sem Agricultura de Precisão. Esperava-se um aumento nos teores de potássio na reamostragem mas não foi encontrado, levantando a hipótese de se fazer uma adubação de manutenção na cultura ao invés de se fazer uma correção de solo.
12

Status of heavy metal (Pb, Cd) pollution in agricultural soil in Dong Mai lead recycling craft village in Hung Yen, Vietnam

Pham, Thi Thao Trang, Phan, Thi Phuong, Nguyen, Khanh Linh, Nguyen, Thi Kim Oanh, Ha, Thi Thu Thuy, Ho, Thi Oanh, Nguyen, Kieu Bang Tam, Nguyen, Thi My Trang, Do, Thi Thu Trang, Nguyen, Thi Hue, Vu, Van Tu, Chu, Thi Thu Ha 07 January 2019 (has links)
The newly planned lead recycling zone in Dong Mai village has been operating with primary treatment systems using lime to neutralize acid in wastewater is a good sign for the local environment, yet the real problem that needs further attention and proper solutions is the accumulation of heavy metals typically lead (Pb) and cadmium (Cd) in agricultural land near the old Pb recycling area. In this context, 27 soil samples were collected and analyzed by AAS method to assess the situation and the quality of the agricultural soil. The results showed that the levels of Cd in the soil were still in acceptable level according to National Regulation. However, the lead contents in all of the soil samples exceeded National Regulation. The level of Pb pollution in soil was inversely proportional to the distance with old lead melting zone. The lead content in the soil sample collected at the distance of 50 m radius to the old melting zone reached 7070 ppm, which was 100 times higher than the allowable value of National Regulation. / Khu tái chế chì mới tại thôn Đông Mai đã được quy hoạch và đi vào hoạt động cùng hệ thống xử lý sơ bộ với vôi bột là một tín hiệu đáng mừng cho môi trường nơi đây, nhưng vấn đề cần quan tâm và giải quyết triệt để là sự tích lũy một lượng lớn kim loại nặng điển hình là chì (Pb) và cađimi (Cd) trong đất nông nghiệp gần những khu tái chế chì cũ. 27 mẫu đất đã được thu thập và phân tích bằng phương pháp AAS để đánh giá tình trạng, chất lượng đất nông nghiệp tại đây. Kết quả cho thấy hàm lượng Cd trong đất vẫn trong mức độ cho phép theo Quy chuẩn quốc gia. Tuy nhiên, 100% các mẫu đất đều có hàm lượng chì vượt quá mức cho phép theo Quy chuẩn quốc gia. Mức độ ô nhiễm Pb trong đất tỷ lệ nghịch với khoảng cách tới khu lò nấu chì cũ. Mẫu đất cách 50 m so với khu vực lò cũ có hàm lượng chì lên tới 7070 ppm, gấp hơn 100 lần so với Quy chuẩn quốc gia.
13

Targeting novel soil glycosyl hydrolases by combining stable isotope probing and metagenomics

Verastegui Pena, Yris Milusqui 14 February 2014 (has links)
Soil represents the largest global reservoir of microbial diversity for the discovery of novel genes and enzymes. Both stable-isotope probing (SIP) and metagenomics have been used to access uncultured microbial diversity, but few studies have combined these two methods for accessing the biotechnological potential of soil genetic diversity and fewer yet have employed functional metagenomics for recovering novel genes and enzymes for bioenergy or bioproduct applications. In this research, I demonstrate the power of combining functional metagenomics and SIP using multiple plant-derived carbon substrates and diverse soils for characterizing active soil bacterial communities and recovering glycosyl hydrolases based on gene expression. Three disparate Canadian soils (tundra, temperate rainforest and agricultural) were incubated with five native carbon (12C) or stable-isotope labelled (13C) carbohydrates (glucose, cellobiose, xylose, arabinose and cellulose). Sampling at defined time intervals (one, three and six weeks) was followed by DNA extraction and cesium chloride density gradient ultracentrifugation. Denaturing gradient gel electrophoresis (DGGE) of all gradient fractions confirmed the recovery of labeled nucleic acids. Sequencing of original soil samples and labeled DNA fractions demonstrated unique heavy DNA patterns associated with all soils and substrates. Indicator species analysis revealed many uncultured and unclassified bacterial taxa in the heavy DNA for all soils and substrates. Among characterized taxa, Salinibacterium (Actinobacteria), Devosia (Alphaproteobacteria), Telmatospirillum (Alphaproteobacteria), Phenylobacterium (Alphaproteobacteria) and Asticcacaulis (Alphaproteobacteria) were the bacterial ???indicator species??? for the heavy substrates and soils tested. Both Actinomycetales and Caulobacterales (genus Phenylobacterium) were associated with metabolism of cellulose. Members of the Alphaproteobacteria were associated with the metabolism of arabinose and members of the order Rhizobiales were strongly associated with the metabolism of xylose. Annotated metagenomic data suggested diverse glycosyl hydrolase gene representation within the pooled heavy DNA. By screening only 2876 inserts derived from the 13C-cellulose heavy DNA, stable-isotope probing and functional screens enabled the recovery of six clones with activity against carboxymethylcellulose and methylumbelliferone-based substrates.
14

Posouzení kvality půdy zpracované klasickým způsobem ve vybrané lokalitě v Olomouckém kraji / Assessment of soil quality processed with conventional tillage in the selected site in the Olomouc region

Drlíková, Barbora January 2017 (has links)
Diploma thesis documents the problems of soil quality, which is assessed on the basis of physical, chemical or biological indicators of soil quality. The paper describes the various indicators, its methodology and evaluation. In the practical part evaluates the quality of soil cultivated with the traditional way - using plowing. The experimental area, where the samples were taken from the soil, lies in the Olomouc region in the municipality Šumvald. Evaluated were selected physical, chemical and physico-chemical properties of soil, e.g. particle size distribution, bulk density, porosity, air capacity, hydrolimits, pH, carbonates, humus content and salinity of the soil.

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