To reduce the uncertainty associated with pesticide fate model predictions on the large scale, a rapid method is needed that can generate sorption coefficients (Kd values) with sufficient spatial detail. The feasibility of near-infrared spectroscopy (NIRS) to act as such a method was examined, using weak-acidic (2,4-D), weak-basic (atrazine) and zwitterion (glyphosate) herbicides and the natural steroid estrogen (17β-estradiol). A total of 609 horizons in 140 soil profiles were collected in agricultural fields near Brandon, Manitoba and near Saskatoon, Saskatchewan. In both agricultural fields, Kd values in horizons generally increased in the order of 2,4-D < atrazine < 17β-estradiol < glyphosate. Soil organic carbon content (SOC) followed by the soil pH were the major factors controlling the sorption of 2,4-D, atrazine and 17β-estradiol but glyphosate showed very strong sorption to soil particles regardless of measured SOC and soil pH values. For the chemicals studied, Kd values decreased from A to C horizons regardless of the segment of the slope from which the soil samples were collected, with the exception of glyphosate that showed relatively large Kd values in B-horizons illuviated with clay. Both the Zeiss Corona and the Foss 6500 spectrophotometers produced significantly strong predictive models for soil properties and Kd values of 2,4-D, atrazine and 17β-estradiol. However, models for glyphosate Kd values were weak or not significant. Using a test set approach and either soil spectral or soil properties data as independent variables, partial least squares regressions were successfully developed to estimate Kd values for use in the Pesticide Root Zone Model (PRZM) to calculate the herbicide mass leached. The study concluded that the added benefit of NIRS will be most useful if the pesticides under study have small sorption potentials and short half-lives in soil. Regional approaches to predicting Kd values from NIRS spectral data can also be developed if the calibration model is derived by combining a set of fields where each has a similar statistical population characteristic in Kd values. / February 2016

As wetlands construídas estão entre as tecnologias eficientes recentemente comprovadas para tratamento e polimento de águas residuárias. Comparando com os sistemas convencionais de tratamento, são de baixo custo, fácil operação e manutenção. Esta pesquisa objetivou avaliar estudos de caso nacionais de utilização de wetlands para tratamento de efluentes em nível terciário com a finalidade de efetuar a remoção de nutrientes, buscando estabelecer parâmetros técnicos, operacionais e de manutenção. Foram avaliados sistemas que utilizaram como macrófita: Typha, Vetiver zizanioides L.Nash, Colocasia esculenta, Hedychium coronarium, Heliconia psittacorum, and Cyperus alternifolius; através de fluxos superficial e subsuperficial; o material filtrante foi brita e areia e o tempo de detenção hidráulica variou de 1,1 a 5 dias. Os resultados encontrados variaram de 5,6 por cento a 93,9 por cento para remoção de nitrogênio amoniacal e de 5 a 90,5 por cento para remoção de fósforo total. Constatou-se que a discrepância entre os resultados está associada ao tempo de detenção hidráulico utilizado, tipo de fluxo escolhido, material filtrante e manejo das macrófitas. Concluiu-se que a wetland construída pode ser usada como tratamento de efluentes em nível terciário para remoção de nutrientes, podendo-se afirmar que: a escolha da combinação de macrófita, material filtrante e fluxo deve ser feita de acordo com o efluente a ser tratado; não há um definição quanto ao tempo de detenção hidráulica ideal para cada sistema o que indica a necessidade de instalar pilotos para avaliação antes de implementar as estações em escala real; a poda deve ser feita respeitando o ciclo de desenvolvimento de cada espécie; é necessário realizar pesquisas que monitorem o sistema a longo prazo para avaliar o seu comportamento. / The constructed wetlands are among of the recently proven efficient technologies for treating and polishing of wastewater. Compared to conventional treatment systems, they are low cost, easily operated and maintained. This study aimed to evaluate national case studies of use of wetlands as a tertiary stage of wastewater treatment in order to make the removing of nutrients and establish technical, operational and maintenance parameters. The evaluated systems used as macrophyte: Typha, Vetiver zizanioides L.Nash, Colocasia esculenta, Hedychium coronarium, Heliconia psittacorum, and Cyperus alternifolius; through surface and subsurface flows; the filter material was gravel and sand and the hydraulic retention time ranged from 1.1 to 5 days. The results ranged from 5.6 per cent to 93.9 per cent for ammonia removal and from 5 to 90.5 per cent for total phosphorus removal. It was found that the discrepancy between the results is associated to the use of hydraulic detention time, to the type of flow, filter material and management of macrophytes. It was concluded that the constructed wetland can be used as tertiary stage of wastewater treatment for nutrients removal, it´s possible to say that: the combination between macrophyte, flow and filter material should be made in accordance with the effluent to be treated ; there is no definition as to the optimal hydraulic retention time for each system indicating the need to install a pilot treatment for evaluation before implementing the seasons full-scale; pruning should be done respecting the development cycle of each species; studies should be conducted to monitor the long-term system to evaluate their behavior.

京都大学 / 新制・論文博士 / 博士(農学) / 乙第13423号 / 論農博第2898号 / 新制||農||1086(附属図書館) / 学位論文||R3||N5346(農学部図書室) / (主査)教授 中嶋 洋, 教授 近藤 直, 教授 飯田 訓久 / 学位規則第4条第2項該当 / Doctor of Agricultural Science / Kyoto University / DFAM

Soil moisture is an important variable in many environmental researches and application areas as it affects the interactions between atmosphere and land surface by controlling the energy and water exchange. The current measurement techniques are insufficient to acquire accurate large-scale root zone soil moisture (RZSM) data at the spatial resolution of interest. Though assorted models have been successfully applied in relatively small areas to estimate RZSM, the large-scale estimation is still facing challenges as it requires the flexibility and practicality of the models for the applications under various conditions. Though physically based soil moisture models are widely used, the errors in model physics affect the flexibility of these models meanwhile their large demand of data and computational resources reduces the practicality. On the contrary, the statistical and data-driven methods have high potential but their applications for large-scale RZSM estimation have not been fully explored. To develop feasible models for large-scale RZSM estimation using the surface observations, artificial neural networks, specifically multilayer perceptrons (MLPs), were applied in this study to estimate RZSM at the depths of 20cm and 50cm, using the data of 557 stations in the United States. Two experiments including four models were developed and the input variables of the models were carefully selected. The sensitivity analysis found that surface soil moisture and the cumulative rainfall, snowfall, air temperature and surface soil temperature were important inputs. If given soil texture data as inputs, the models achieved better performance and were extremely sensitive to them. The results showed that the MLPs were effective and flexible for the estimation of soil moisture at 20cm under various climate types and were insensitive to the potential errors in soil moisture datasets. However, the results of the estimation at 50cm are not as good as that of the 20cm. / Thesis / Master of Science (MSc)

Good estimates of soil hydraulic parameters and their distribution in a catchment is essential for crop and hydrological models. Measurements of soil properties by experimental methods are expensive and often time consuming, and in order to account for spatial variability of these parameters in the catchment, it becomes necessary to conduct large number of measurements. Estimation of soil parameters by inverse modelling using observations on either surface soil moisture or crop variables has been successfully attempted in many studies, but difficulties to estimate root zone properties arise for heterogeneous layered soils. Although extensive soil data is becoming more and more available at various scales in the form of digital soil maps there is still a large gap between this available information and the input parameters needed for hydrological models. Inverse modeling has been extensively used but the spatial variability of the parameters and insufficient data sets restrict its applicability at the catchment scale. Use of remote sensed soil moisture data to estimate soil properties using the inverse modeling approach received attention in recent years but yielded only an estimate of the surface soil properties. However, in multilayered and heterogeneous soil systems the estimation of soil properties of different layers yielded poor results due to uncertainties in simulating root zone soil moisture from remote sensed surface soil moisture. Surface soil properties can be estimated by inverse approach using surface soil moisture data retrieved from remote sensing data. Since soil moisture retrieved from remote sensing is representative of the top 5 cm only, inversion of models using surface soil moisture cannot give good estimates of soil properties of deeper layers. Crop variables like biomass and leaf area index are sensitive to the deeper layer soil properties. The main focus of this study is to develop a methodology of estimation of root zone soil hydraulic properties in heterogeneous soils by crop model based inversion techniques. Further the usefulness of the radar soil moisture and leaf area index in retrieving soil hydraulic properties using the develop approach is be tested in different soil and crop combinations. A brief introduction about the soil hydraulic properties and their importance in agro-hydrological model is discussed in Chapter 1. Soil water retention parameters are explained in detail in this chapter. A detailed review of the literature is presented in chapter 2 to establish the state of art on the following: (i) estimation of soil hydraulic properties, (ii) role of crop models in estimating soil hydraulic properties, (iii) retrieval of surface soil moisture using water cloud model from SAR data, (iv) retrieval of leaf area index from SAR (synthetic aperture radar) data and (v) modeling of root zone soil moisture and potential recharge. The thesis proposes a methodology for estimating the root zone soil hydraulic properties viz. field capacity, wilting point and soil thickness. To test the methodology developed in this thesis for estimating the soil hydraulic properties and their uncertainty, three synthetic experiments were conducted by inversion of STICS (Simulateur mulTIdiscplinaire pour les Cultures Standard) model for maize crop using the GLUE (Generalized Likelihood Uncertainty Estimation) approach. The estimability of soil hydraulic properties in a layer-wise heterogeneous soil was examined with several sets of likelihood combinations, using leaf area index, surface soil moisture and above ground biomass. The robustness of the approach is tested with parameter estimation (model inversion) in two different meteorological conditions. The details of the numerical experiments and the several likelihood and meteorological cases examined are given in Chapter 3. The likelihood combination of leaf area index and surface soil moisture provided consistently good estimates of soil hydraulic properties for all soil types and different meteorological cases. Relatively wet year provided better estimates of soil hydraulic properties as compared with a dry year. To validate the approach of estimating root zone soil properties and to test the applicability of the approach in several crops and soil types, field measurements were carried out in the Berambadi experimental watershed located in the Kabini river basin in south India. The profile soil measurements were made for every 10 cm upto 1 m depth. Maize, Marigold, Sunflower, Sorghum and Turmeric crops were monitored during the four year period from 2010 to 2013. Crop growth parameters viz. leaf area index, above ground biomass, yield, phenological stages and crop management activities were measured/monitored at 10 day frequency for all the five crops in the study area. The details of the field experiments performed, the data collected and the results of the model inversion using the ground measured data are given in Chapter 4. The likelihood combination of leaf area index and surface soil moisture provided consistently lower root mean square error (1.45 to 2.63 g/g) and uncertainty in the estimation of soil hydraulic properties for all soil crop and meteorological cases. The uncertainty in the estimation of soil hydraulic properties was lower in the likelihood combination of leaf area index and soil moisture. Estimability of depth of root zone showed sensitivity to the rooting depth. Estimating root zone soil properties at field plot scale using SAR data (incidence angle 24o, wave length 5.3 GHz) of RADARSAT-2 is presented in the Chapter 5. In the first step, an approach of estimating leaf area index from radar vegetation index using the parametric growth curve of leaf area index and the retrieval of soil moisture using water cloud model are given in Chapter 5. The parameters of the growth curve and the leaf area index are generated using a time series of RADARSAT-2 for two years 2010-2011 and 2011-12 for the crops (maize, marigold, sunflower, sorghum and turmeric) considered in this study. The surface soil moisture is retrieved using the water cloud model, which is calibrated using the ground measured values of leaf area index and surface soil moisture for different soils and crops in the study area. The calibration and validation of LAI and water cloud models are discussed in this Chapter. Eventually, the retrieved leaf area index and surface soil moisture from RADARSAT-2 data were used to estimate the soil hydraulic properties and their uncertainty in a similar manner as discussed in Chapter 4 for various crop and soil plots and the results are presented in Chapter 5. The mean and uncertainty in the estimation of soil hydraulic properties using inversion of remote sensing data provided results similar to the estimates from inversion of ground data. The estimates of soil hydraulic properties compared well (R2 of 0.7 to 0.80 and RMSE of 2.1 to 3.16 g/g) with the physically measured vales of the parameters. In Chapter 6, root zone soil moisture and potential recharge are modelled using the STICS model and the soil hydraulic parameters estimated using the RADARSAT-2 data. The potential recharge is highly sensitive to the water holding capacity of rooting zone. Variability in the root zone soil moisture for wet and dry years for different soil types on irrigated and non-irrigated crops were investigated. Potential recharge from different crop and soil types were compared. The uncertainty in the estimation of potential recharge due to uncertainty in the estimation of field capacity is quantified. The root zone soil moisture modeled by STICS showed good agreement with the measured root zone soil moisture in all crop and soil cases. This was tested for both dry and wet year and provides similar results. The temporal variability of root zone soil moisture was also modeled well by the STICS model; the model also predicted well the intra-soil variability of soil moisture of root zone. The results of the modeling of root zone soil moisture and potential recharge are presented in Chapter 6. At the end, in Chapter 7, the major conclusions drawn from the various chapters are summarized.

The growing season for vegetable crops is limited by freezing temperatures in arid high elevation climates such as northern Utah. Logan, Utah (41.73 N, 111.83 W, 1382 m elevation) has a short, variable growing season with an average frost-free period of 135 days. Extending the growing season provides growers with an opportunity to extend revenue into a normally unproductive period and benefit from out-of-season price premiums. High tunnels have been used to effectively extend the growing season for numerous crops by providing cold temperature protection. However, limited high tunnel research has been performed in arid high elevation regions that experience extreme temperature fluctuations. The use of high tunnels was investigated in North Logan, Utah to extend the growing season for tomatoes and lettuce. In 2009 and 2010, supplemental heating under low tunnels within high tunnels was investigated to provide early season cold temperature protection for tomatoes. Sunbrite tomatoes were transplanted into four high tunnels over three planting dates. Tomatoes were subjected to supplemental heating treatments including soil warming cables alone or in conjunction with 40-watt incandescent lights for air heating. The highest early season and overall yield was achieved with the 17 Mar. planting date. Early season yield was significantly less for the latest planting date (7 Apr.) compared to the 17 Mar. and 30 Mar. planting dates. Early season yield was significantly greater for treatment plots with soil plus air heating, and soil heating alone significantly improved total yield. The use of a vertical structure within a high tunnel was investigated to improve productivity for lettuce. Parris Island Cos lettuce was consecutively transplanted from spring 2008 to spring 2010 in a high tunnel at the same site. The vertical growing system allowed for 31 plants*m-2 in south oriented gutters, and 45 plants*m-2 in east/west oriented gutters compared to 25 plants*m-2 in the ground including space for maintenance. Root zone temperatures in the gutters fluctuated widely in response to air temperatures, and super-optimal soil temperatures impeded growth. Productivity (g*m-2) in the gutters was only significantly greater than productivity in the ground soil during the spring and fall months when soil and air temperatures were not frequently below 0 °C or above 24 °C. This thesis includes both research results and extension factsheets intended for growers interested in high tunnel production of tomato and lettuce.

Made available in DSpace on 2014-07-29T15:01:43Z (GMT). No. of bitstreams: 1 dissertacao daniela de s s bufaical 2010.pdf: 546520 bytes, checksum: 6c1b30b52d2b46ab060381d4e8c948d9 (MD5) Previous issue date: 2010-08-31 / This study aimed to evaluate the efficiency of a constructed wetlands planted with the vegetal species white ginger (Hedychium coronarium J. König), narrow leaf cattail (Typha angustifolia L.) and papyrus sedge (Cyperus gigantus) under three charges application of the sludge from the sewage treatment station of Goiânia, Goiás, Brazil, in the reduction of thermotolerant coliforms and viable helminths eggs and sludge dewatering. It also aimed to characterize the sludge and to evaluate the quality of the filtrate, and to investigate the occurrence of substances excreted by the macrophytes roots, which may help reduce pathogens. The experiment was conducted at the Goiânia sewage treatment station. To evaluate the reduction of pathogens, the sludge dewatering and the filtrate quality were used 12 plastic containers, each one with 1 m3 of volumetric capacity, filled with support media containing 5 cm of gravel number one, a geotextile blanket and 20 cm of sand. In the gravel was installed a drainage system of gases, consisting of a PVC tube with 25 mm in diameter, in an "L" format, whose horizontal portion was drilled with holes of 4 mm in diameter. The sludge was applied at application rates of 43, 140 and 248 kg TS m-2 year, bringing the rates of 20, 70 and 120 L m-2 week, respectively. The applications of sludge were divided into two times a week, half on Tuesdays and half on Fridays. After three months of application, samples were taken from the dewatered sludge every 14 days, and sent to the laboratory for solids, thermotolerant coliforms and viable helminths eggs determination. During three weeks the filtrate was collected in each container and submitted to analysis of solids and thermotolerant coliforms. To investigate the release of toxins by macrophytes roots were used four 20 L buckets containing sand as support medium. Three buckets were planted with the species of macrophytes and one wasn t planted. The buckets were irrigated with dechlorinated water for four months, keeping the water level inside the buckets at 5 cm from the substrate surface. After this period 2 L samples of effluent from each bucket were collected and sent to the laboratory to investigate the antimicrobial activity. The results were analyzed using the Statistical Analysis System (SAS), performing F and Tukey Kramer (5% probability) tests. About the filtrate there was no significant difference in the removal of solids and thermotolerant coliforms in the rates of 70 L m-2 week and 120 L m-2 week. At the rate of 20 L m-2 week there was no filtrated material. For the dewatered sludge there was no significant difference in the removal of thermotolerant coliforms, viable helminths eggs and solids concentration among the treatments. The total solids were lower at the application rate of 120 L m-2 week. Plant development was hampered by sludge application and at the application rate of 120 L m-2 week, the species narrow leaf cattail and papyrus sedge had died after three months of sludge aplication. The extracts found at the water in contact with the macrophytes roots didn t inhibit microbial activity. The dewatered sludge treated by the constructed wetlands attended the 375 Conama Resolution for type A sludge for viable helminthes eggs and for type B sludge for thermotolerant coliforms / Os objetivos deste estudo foram avaliar a eficiência do sistema de tratamento do tipo leito de macrófitas plantados com as espécies vegetais lírio do brejo (Hedychium coronarium J. König), taboa (Typha angustifolia L.) e papirus (Cyperus gigantus), em três taxas de aplicação de lodo da Estação de Tratamento de Esgoto de Goiânia, na redução de coliformes termotolerantes e de ovos viáveis de helmintos e no desaguamento do lodo. Realizar a caracterização do lodo e avaliar a qualidade do filtrado, bem como investigar a ocorrência de liberação de substâncias excretadas pelas raízes das macrófitas, que possam auxiliar na redução dos patógenos. O experimento foi conduzido na ETE Goiânia (GO). Para avaliação da redução dos patógenos, desaguamento do lodo e avaliação do filtrado foram utilizados 12 contenedores plásticos de 1 m3 cada, preenchidos com meio suporte contendo 5 cm de brita no 1, manta geotextil e 20 cm de areia. Na brita foi instalado um sistema de drenagem de gases, constituído por um tubo de PVC de 25 mm de diâmetro, em formato de ele , cuja parte horizontal foi perfurada com furos de 4 mm de diâmetro. Na areia foram plantadas mudas das espécies vegetais, oito mudas por contenedor. Três contenedores não foram plantados, servindo de tratamento testemunha. Nos contenedores o lodo foi aplicado em taxas de 43, 140 e 248 kg ST m-2 ano, perfazendo as taxas de 20, 70 e 120 L m-2 semana, respectivamente. As aplicações do lodo foram realizadas duas vezes por semana, metade na terça-feira e metade sexta-feira. Após três meses de aplicação, foram realizadas coletas do lodo desaguado a cada 14 dias, e enviadas ao laboratório para realização das análises de sólidos totais, coliformes termotolerantes e ovos viáveis de helmintos. Durante três semanas foi coletado o filtrado de cada contenedor para realização das análises de sólidos totais e coliformes termotolerantes. Para investigação da liberação de toxinas pelas macrófitas foram utilizados quatro baldes de 20 L contendo meio suporte de areia lavada. Os baldes foram plantados com cada espécie de macrófita e um não foi plantado. As macrófitas plantadas nos baldes foram irrigadas com água sem cloro durante quatro meses, mantendo-se o nível de água a 5 cm da superfície do substrato. Após esse período foram coletados 2 L de amostra de efluente de cada balde e enviadas para o laboratório de pesquisa de produtos naturais para a realização de ensaios de investigação de atividade antimicrobiana. Os resultados foram analisados pelo Statistical Analysis System (SAS), realizando-se os testes F e de Tukey Kramer, a 5% de probabilidade. No filtrado não houve diferença significativa na remoção de sólidos totais e coliformes termotolerantes nas taxas 70 L m-2 semana e 120 L m-2 semana e a taxa 20 L m-2 semana não apresentou filtrado. No lodo não houve diferença significativa na remoção de coliformes termotolerantes, ovos viáveis de helmintos e concentração de sólidos entre os tratamentos. A concentração de sólidos totais foi menor na taxa de aplicação de 120 L m-2 semana. O desenvolvimento das plantas foi prejudicado pela aplicação do lodo e na taxa 120 L m-2 semana, após 3 meses de aplicação, as espécies vegetais taboa e papirus morreram. Os extratos encontrados na água em contato com as raízes das macrófitas não inibiram a atividade microbiana. O lodo submetido ao tratamento do tipo leito de macrófitas atende à Resolução Conama 375 para o lodo tipo A para ovos viáveis de helmintos e lodo tipo B para coliformes termotolerantes.

Submitted by Franciele Moreira (francielemoreyra@gmail.com) on 2017-11-03T17:48:11Z No. of bitstreams: 2 Dissertação - Lullyane de Queiroz Rodrigues Barrero - 2017.pdf: 1767328 bytes, checksum: 812e2f494e644474c6532429fef8f34b (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2017-11-06T09:53:51Z (GMT) No. of bitstreams: 2 Dissertação - Lullyane de Queiroz Rodrigues Barrero - 2017.pdf: 1767328 bytes, checksum: 812e2f494e644474c6532429fef8f34b (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2017-11-06T09:53:51Z (GMT). No. of bitstreams: 2 Dissertação - Lullyane de Queiroz Rodrigues Barrero - 2017.pdf: 1767328 bytes, checksum: 812e2f494e644474c6532429fef8f34b (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2017-09-21 / The endocrine disrupting compound 17 α-ethinylestradiol (EE2), present in female contraceptives, after consumption, is eliminated by urine and goes into the sewer system. Conventional sewage treatment methods cannot properly remove such chemical which is then carried into the receiving bodies, where they are capable of mimicking, antagonizing or negatively altering steroids levels of various aquatic organisms. The purpose of this study was to evaluate the usage potential of soil covered with Buddhas's Belly bamboo (Bambusa tuldoides cv. ventricosa) in removing EE2 from sewage. For this, 760 mL of sanitary sewage containing 2 mg EE2/L; 2.5 mg EE2/L; 3 mg EE2/L and 3.5 mg EE2/L, were applied in 10L plastic pots, with grown Buddha's Belly bamboo plants. The drained fluid from each pot was collected, measured and subjected to EE2 concentration analysis. The efficiency of EE2 load (concentration times volume) removal was calculated and the treatments were compared. The efficiency of EE2 removal was 80.22%; 87.44%; 89.65% and 95.33% respectively for sewage with EE2 concentrations of 2 mg/L; 2.5 mg/L; 3 mg/L and 3.5 mg/L. The efficiency of EE2 removal by soil covered with bamboo increased as the concentration of hormone increased. / O desregulador endócrino 17α-etinilestradiol (EE2), presente nos anticoncepcionais femininos, após consumido é eliminado pela urina e vai para o efluente. Os sistemas convencionais de tratamento não conseguem removê-lo de forma adequada e são então dispostos nos corpos receptores, onde são capazes de mimetizar, antagonizar ou alterar de forma negativa os níveis de esteroides de vários organismos. O objetivo do presente trabalho foi avaliar o potencial do uso do solo vegetado com bambu barriga de Buda (Bambusa tuldoides cv. ventricosa) para a remoção do EE2 do efluente. Para tanto, foram aplicados 760 mL de efluente sanitário contendo concentrações de 2 mg/L; 2,5 mg/L; 3 mg/L e 3,5 mg/L de EE2, em vasos plásticos de 10 litros de capacidade volumétrica, plantados com o bambu. O líquido drenado de cada vaso foi coletado, medido e submetido a análise de determinação da concentração de EE2. Calcularam-se as eficiências de remoção da quantidade absoluta de EE2 (concentração vezes volume) e compararam-se os tratamentos. A eficiência na remoção de EE2 foi de 80,22%; 87,44%; 89,65% e 95,33%, respectivamente, para o efluente aplicado nas concentrações de 2 mg/L; 2,5 mg/L; 3 mg/L e 3,5 mg/L de EE2. A eficiência de remoção do EE2 pelo solo vegetado com bambu cresceu com a concentração de hormônio aplicada, sendo parte deste hormônio absorvido pela planta, devido a capacidade do EE2 mimetizar outros hormônios, e outra parte adsorvida no solo que atuou como filtro.

Thesis (M.Sc. (Horticulture)) -- University of Limpopo, 2020 / The South African Agricultural Sector has a mandate to reduce water use so that water can be available for other economic sectors. Thus, various water saving techniques must be continuously investigated in agricultural production to find efficient water use technique that saves water without compromising fresh fruit quality. Therefore, combined effect of irrigation method, 1-methylcyclopropene (1-MCP) and cold storage temperature on postharvest quality of ‘Hass’ avocado fruit was evaluated. Postharvest attributes of fruit colour, flesh firmness, ripening percentage, respiration, weight loss, body rot, stem end-rot, vascular browning, chilling injury and electrolyte leakage were assessed for 2 x irrigation methods [Full irrigation (FI) and Partial root-zone drying (PRD)], 2 x 1-methylcyclopropene (300 ng/L 1-MCP and untreated) and 2 x storage temperature (2.0 and 5.5°C) treatments. An interaction between the three treatments did not significantly (P > 0.05) influence fruit colour, flesh firmness, ripening percentage, fruit weight loss, body rot, stem end-rot, vascular browning, chilling injury and electrolyte leakage. Their combined effect was only significant (P = 0.019) on ‘Hass’ fruit respiration rate. The combination of full and PRD irrigation, 1-MCP and low storage temperature (2.0°C) did not negatively affect fruit quality. However, fruit stored at 2.0°C without 1-MCP treatment were affected by chilling injury when compared with fruit stored at 5.5°C. In conclusion, due to the inconclusiveness of results obtained, further studies, on the effect of these treatments especially under 5.5°C storage temperature should be carried out prior recommending the combination treatment for export markets. / Agricultural Research Council-Tropical and Subtropical Crops (ARC-TSC) and Agricultural Sector Education Training Authority (AgriSeta)

Root-zone soil moisture (RZSM) is an important variable when forecasting plant growth, determining water availability during drought, and understanding evapotranspiration as a flux. However, current methods indirectly estimate RZSM using data assimilation, which requires time-series data to make model-based predictions. This is because direct measurement requires a lower frequency signal, typically P-band and below (<500MHz), to reach root zone depths and, in turn, necessitates a larger antenna to be deployed in space, which is often unfeasible. A new remote sensing technique known as Signals of Opportunity (SoOp) reutilizes transmitted communication signals to perform microwave remote sensing. This means that SoOp platforms need not include a transmitter, but rather rely on passive radar technology to make measurements. This thesis details the development of a UAS-based P-band SoOp receiver instrument. This platform will be used to progress the state-of-art in techniques for direct measurement of RZSM.