Three systems for filtering polluted river water for use in subsurface irrigation have been designed, operated and evaluated. One system consisted of filtering the water through filter basins covered with grass. The second system used geotextiles in filter basins. The third system consisted of flooding a section of a field. In this system, the water was filtered as it moved through the soil towards the subsurface drainage/irrigation drain pipes. / It was found that grass filter basins are very efficient in removing sediment from river water. Grass filter basins having drain pipes placed in trenches 30 cm wide backfilled with sand gave the best results. More than 90% of sediments were removed from the river water. From the outflow measurements, it was found that less than 0.2% of the field to be irrigated needs to be devoted to the filtration system. / Important filter design parameters, namely filtration rates per unit area of filter basin and per unit length of filter trench and drain pipe, were determined. / Due to the fast clogging of the geotextile, filtration of river water through basins covered with geotextile was found to be impractical and expensive, as compared to filtration using water tolerant grasses as a basin cover. / Flooding a section of the crop land combined with controlled drainage was found to be an efficient way of irrigating maize crop. The yields obtained with this system were comparable with those obtained with conventional subsurface irrigation. Flood irrigation combined with controlled drainage would be particularly commendable on relatively flat fields which have subsurface drains.

No description available.

Irrigation water is perhaps the leading pre-harvest source of contamination of fresh vegetables in the world. In this thesis, the effect of source water from the Olifants River and the Wilge River on the bacterial quality of water in the Loskop Canal that they feed and also the subsequent contribution to the bacterial contamination of fresh vegetables was determined for a period of twelve months. Also effect of attachment time on the survival of Listeria monocytogenes and the effect of chlorine on L. monocytogenes attached to vegetables were determined. Finally, a step-wise logistic regression analysis was made to determine whether various predictor variables could be used to predict the occurrence of L. monocytogenes, Salmonella spp and intestinal Enterococcus in irrigation water and vegetables (i.e., cauliflower and broccoli). COD and turbidity were higher in the Olifants River and the Wilge River than in the Loskop Canal that they feed, according to the water guidelines set by the World Health Organisation (WHO) and the Republic of South Africa (RSA). The level of the COD and turbidity were significantly different in terms of the two rivers in comparison with the canal. Levels of faecal coliforms and Escherichia coli were also higher than the WHO standard. Staphyloccocus aureus, intestinal Enterococcus, Salmonella, L. monocytogenes were recovered from the two rivers and the canal. Apart from L. monocytogenes that was not recovered from cauliflower, all bacterial pathogens recovered from the surface water were recovered from the vegetables. This study also indicated that L. monocytogenes could attach to both surface and subsurface structures of both tomatoes and spinach within 30 min, and that even after 72 h, it still remained viable. It also indicated that chlorine treatment is more effective against surface L. monocytogenes compared with subsurface inoculated L. monocytogenes. Finally, the logistic regression analysis of the sampled data showed that COD was statistically reliable to indicate a high probability of L. monocytogenes, turbidity reliable to indicate a high probability of intestinal Enterococcus and faecal coliforms and coliforms reliable to indicate a high probability of Salmonella in irrigation water. Low aerobic colony count (ACC) was statistically significant for the prediction of the three pathogens on vegetables. / Thesis (PhD)--University of Pretoria, 2010. / Food Science / unrestricted

Submitted by Deyse Queiroz (deysequeirozz@hotmail.com) on 2018-06-12T13:52:34Z No. of bitstreams: 1 LEOBERTO DE ALCANTARA FORMIGA - TESE PPGEA 2011..pdf: 51573858 bytes, checksum: d1deea651191371be4e9ae618751f7f2 (MD5) / Made available in DSpace on 2018-06-12T13:52:34Z (GMT). No. of bitstreams: 1 LEOBERTO DE ALCANTARA FORMIGA - TESE PPGEA 2011..pdf: 51573858 bytes, checksum: d1deea651191371be4e9ae618751f7f2 (MD5) Previous issue date: 2011-11 / Neste trabalho foram estudados diferentes aspectos do manejo da cultura da mamona em condições de campo, visando à otimização do uso da água, e ao rendimento da mamona, em primeiro e segundo ciclos, obtido em condições de rebrote através de poda. A pesquisa foi desenvolvida no Centro de Ciências Agrárias e Ambientais - CCAA, Campus II da Universidade Estadual da Paraíba - UEPB, localizado no Sítio Imbaúba, s/n, Zona Rural, Município de Lagoa Seca - PB, Microrregião de Campina Grande, Agreste Paraibano, com altitude média de 634 m, no período de outubro de 2008 a outubro de 2009. O solo utilizado foi um franco-arenoso com baixo teor de matéria orgânica. O delineamento experimental foi o de blocos ao acaso, em esquema fatorial 2 x 4 , constituído de dois cultivares de mamona (BRS 149 - Nordestina e o BRS 188 - Paraguaçu) e quatro níveis de água disponível no solo (40,60, 80 e 100%), distribuídos em 3 blocos. A área útil de cada parcela experimental era de 100 m2 na qual foram cultivadas 50 plantas, espaçadas 2m x lm. O solo foi adubado com superfosfato triplo em fundação na quantidade de 120 kg.ha"1 de P2Os e em cobertura de 100 kg.ha"1 de K2O e de 100 kg-ha"1 de N, nas formas de cloreto de potássio e ureia, parcelados em porções igualitárias em intervalos de 10 dias, aplicadas via fertirrigação, a primeira aplicação 1 ocorrendo 20 dias após o semeio. O experimento foi conduzido durante dois ciclos i :. consecutivos de 180 dias, o segundo realizado a partir de uma poda drástica das plantas, na altura de 30 cm em relação ao nível do solo. O conteúdo de água dispomvel do solo foi monitorado na frequência de dois dias, através de uma sonda de TDR segmentada. Os dados ? foram analisados estatisticamente utilizando-se o programa SISVAR - ESAL - Lavras, MG, através do qual foi feita a análise de variância (ANAVA), aplicando-se os Testes F e de Tukej^^--' j para a comparação das médias dos tratamentos e análise de regressão para o fator quantitativo de água dispomvel. Avaliaram-se: altura, diâmetro do caule, área foliar e inflorescências: dias para emissão da I a inflorescência e sua respectiva altura e número total de inflorescências, fitomassa, razão de área foliar, consumo e eficiência do uso da água, produção de frutos e sementes e teor de óleo nas sementes. Verificou-se que o aumento da disponibilidade hídrica no solo aumentou todos os índices de crescimento e/ou desenvolvimento das plantas, com incrementos substanciais na produtividade e na qualidade final do produto. O segundo ciclo da cultura, obtido a partir da poda drástica, apresentou padrões de crescimento e/ou desenvolvimento e capacidade produtiva semelhantes aos do primeiro ciclo, com elevado padrão de qualidade do produto final, demonstrando a viabilidade técnica de condução a um segundo ciclo da mamona, a partir da poda drástica das plantas. / This study examined different aspects of management of castor bean in the field, aiming to optimize water use and yield of castor bean in the first and second cycle, obtained under conditions of regrowth through pruning. The research was conducted at the Centro de Ciências Agrárias e Ambientais - CCAA, Campus II da Universidade Estadual da Paraíba - UEPB, located on the Sitio Imbaúba, s/n, Rural Zone, Lagoa Seca, PB, Micro region of Campina Grande, Paraiba Agrestic, with an average altitude of 634 m in the period October 2008 to October 2009. It was used a sandy loam soil with low organic matter content. The experimental design was randomized blocks in factorial 2 x 4 , consisting of two castor bean cultivars (BRS 149 - Nordestina and BRS 188 - Paraguaçu) and four leveis of available soil water (40, 60, 80 and 100 %), distributed in three blocks. Each plot had a surface area of 100 square meters where they were cultivated 50 plants, spaced 2m x lm. The soil was fertilized with triple superphosphate in foundation in the amount of 120 kg ha"1 P2O5 and included 100 kg.ha"1 K2O and 100 kg.ha"1 N in the forms of potassium chloride and urea, split in equal portions at intervals of 10 days via fertigation, with the first application occurring 20 days after sowing. The experiment was conducted for two consecutive cycles of 180 days, and the second cycle performed from a drastic pruning of the plants to a height of 30 cm from the ground levei. The available water content of soil was detected and replaced at intervals of two days through a segmented TDR probe. The data were statistically analyzed using the program SISVAR - ESAL - Lavras, MG, which was made through the analysis of variance (ANOVA), applying the F test and Tukey test for comparison of treatment means and regression analysis for the quantitative factors available water. They were evaluated: height, stem diameter, leaf area, flowering, days to issue their lst and their respective height and total number of inflorescences, biomass, leaf area ratio, consumption and efficiency of water use, production of fruits and seeds and oil content in seeds. It was found that increased soil water availability has increased ali índices of growth and / or development of plants with substantial increases in productivity and quality of the final product. The second cycle of the culture obtained from the drastic pruning, showed growth patterns and/or development and production capabilities similar to the first cycle, with high standards of product quality, demonstrating the feasibility of conducting a second round os castor from a drastic prining os the plants.

Thesis (M. Tech. (Agriculture)) -- Central University of Technology, Free state, 2011 / Quality assessment of agricultural water used for fertigation in the Boland district. The study was undertaken to determine the influence of seasonal changes on the water quality (chemical and microbial analyses) of five different rivers in the Boland. The data was collected in the five most important water sources that are used for irrigation purposes in the district, i.e. Berg river, Eerste river, Klapmuts River, Klippies river and Krom river. The samples were collected from all sites once every three weeks for a period of six months. The sampling was carried out during specific periods in summer (December, 2006 to February, 2007) and winter (June to August, 2007). The results of the study showed that Klapmuts river recorded the highest levels of chloride and iron, especially in summer. However, chloride levels were far below the levels set by the Department of Water Affairs and Forestry. Results obtained from this study show the presence of pathogens in some of the rivers assessed which may have resulted from the leaching of these pathogens from nearby agricultural land, livestock watering or informal settlements in the catchment areas. The bigger rivers recorded low levels of micro-elements and this might have been affected by winter rainfall. In the Berg River, many sources of nitrate pollution seem to be present in the catchment area. The levels of iron in all the rivers assessed were far more than the levels set by the Department of Water Affairs and Forestry in all rivers assessed and these might be due to the pH levels and interaction between the rivers and seasons. Iron and manganese levels should be kept low as this may cause production problems by blocking irrigation drippers. The water samples tested for bacterial and fungal density showed Klapmuts and Eerste rivers were positive for Phytophthora cinnamomi during winter. Phytophthora citricola and Phytophthora cactorum were detected in the Klapmuts and Klippies rivers in summer. The Berg-, Klapmuts-, Krom- and Eerste rivers tested positive for species of the genera Pythium and Fusarium. Similar organisms were detected in the Eerste river mainly during summer on the fourth sampling date, while Krom river only tested positive for Pythium during summer. The total bacterial and algal density differed significantly between the seasons and was highest in winter. This might be due to high rain water influx and efflux and/or moist and aerobic conditions and air temperature. There is an increased need for farmers to sterilize feeding water (chlorination) due to high microbial count.

Among ornamental plants, roses (Rosa L.) are considered the most economically important, being among the most popular garden shrubs, as well as the favorite cut flowers sold by florists. In the past roses have been classified as fairly salt-sensitive, however, recent nutrition studies suggest that they may actually tolerate moderate to relatively high salinities. The general objective of this research was to reassess the limits of tolerance to salinity of roses and the influence of the rootstock used, to determine the ameliorative properties of supplemental Ca2+ on the response to salt stress, and to establish the influence of Na+- and Cl--counter ions on the detrimental effects caused by these salinizing elements. The NaCl or NaCl-CaCl2-salinity tolerance limit for greenhouse roses, although greatly influenced by the rootstock, was between 12 and 15 mmol.L-1. Plants grafted on ?Manetti? sustained their productivity/quality characteristics for longer time periods, tolerated greater salinity concentrations, and accumulated less Cl- and Na+ in leaves of flowering shoots than those grafted on ?Natal Briar?, confirming the greater ability of the former rootstock to tolerate salt stress. Supplementing the saline solution with 0-10 mmol.L-1 Ca2+ (as CaSO4) did not alleviate the harmful effects caused by NaCl-salt stress (12 mmol.L-1) on the productivity and quality responses of roses. The detrimental effects caused by Na- and Cl-based salinity were greatly influenced by the composition of the salt mixtures (i.e. their counter ions). Sodium sulfate and CaCl2 were the least harmful salts; NaCl had intermediate effects, while NaNO3 and KCl were the most deleterious. Among the most distinguishable effects caused by the more toxic Na+ and Cl- counter ions were lower osmotic potential (piSS) and greater electrical conductivity (ECSS) of the salinized solutions, markedly increased uptake and/or transport of either Na+ or Cl- to the flowering shoot leaves, and altered uptake and/or transport of other mineral nutrients. Computations of the saline solutions? chemical speciation revealed that salts containing divalent ions had lower ionization and exhibited greater ion associations compared to monovalent ion salts, rendering a lower number in free ions/molecules in solution which caused greater SS and lower ECSS in those solutions.

Thesis (MSc Food Sc)--Stellenbosch University, 2012. / ENGLISH ABSTRACT: The agricultural sector of South Africa is currently facing a serious water crisis. The decreased availability of water as a result of climate change and the constantly growing population has left many farmers increasingly dependant on surface water as primary source of irrigation. Urbanisation along with out-dated and insufficient wastewater treatment works have all contributed to polluting large volumes of these resources. Consequently, many farmers have been forced to use irrigation water, not only of poor quality, but often water which has been polluted with untreated sewage. As a result, this project aimed at investigating the link between the quality of irrigation water and the impact on the safety of fresh produce. A base-line of the microbial load at three sites along the Plankenburg and Eerste Rivers was established using standard microbial methods for the detection of indicator organisms such as total and faecal coliforms, Escherichia coli and Enterococci as well as potential pathogens that included Salmonella, Listeria, Staphylococcus, endosporeformers and aerobic colony counts. Chemical parameters such as pH, alkalinity, conductivity and chemical oxygen demand (COD) were also monitored, but were not correlated to microbial pollution levels in the rivers. High faecal coliform and E. coli concentrations, ranging from 310 to 7 x 106 cfu.100 mL-1 and 230 to 7 x 106 cfu.100 mL-1, respectively, were detected. The recommended irrigation water guidelines of ≤1 000 (WHO, 1989) and ≤4 000 cfu.100 mL-1 (DWAF, 2008) for faecal coliforms and E. coli were exceeded, indicating faecal pollution and thus a high health risk. This health risk was confirmed when potential pathogens such as Aerococcus viridans, Klebsiella, Listeria monocytogenes and Salmonella typhimurium were detected at all three sites. The carryover of organisms from rivers to produce (green beans and grapes) was investigated by comparing the microbial population of the Plankenburg and Eerste Rivers to the population recovered from irrigation water and the surface of fresh produce. Faecal coliforms, E. coli, Aerococcus viridans, Enterobacter aerogenes, Klebsiella, L. innocua, L. grayi, L. monocytogenes and Staphylococcus aureus were detected in all three sample types, indicating a similarity between the microbial populations found in the river, the irrigation water and produce. Thus, the transfer of potential pathogens from the rivers to produce is a strong possibility. The build-up of organisms on the surface of green beans as a result of multiple irrigations was also confirmed by an increase in faecal coliform concentrations from initial concentrations of none detected to 44 000 cfu.100 mL-1 over a 10 day irrigation period. Finally, microbial source-tracking techniques including multi-antibiotic resistance (MAR) profiling, and the API 20E classification system were used to determine genotypic and phenotypic characteristics of 92 faecal isolates (from irrigation water and produce) and 13 reference strains. Numerical classification systems was used to classify the 105 faecal isolates according to the degree of similarity between the genotypic and phenotypic characteristics of the 105 isolates. A high degree of similarity indicates a high probability that isolates originate from the same strain and therefore from the same source, thereby confirming the transfer of organisms Faecal isolates (93 and 98%, respectively) were found to be resistant to Vancomycin at both the 5 and 30 μg concentrations. The majority of isolates presented some resistance to Erythromycin (15 μg) and Ampicillin (25 μg), with 82% of isolates presenting an inhibition zone ≤4 mm. Isolates were sensitive towards Ciprofloxacin (1 and 5 μg), Ofloxacin (15 μg), Ceftriaxone (30 μg) and Cefotaxime (5 μg), which were able to inhibit the growth of 79.8, 93.3, 79.8, 88.5 and 71.2% of the isolates, respectively. The 13 medical reference strains all presented different genotypic and phenotypic characteristics and thereby indicated a high degree of variability between isolates from the same species. Finally, 35% of the isolates could be grouped together based on similar genotypic and phenotypic characteristics, therefore, more than a third of the faecal isolates obtained from the surface of the fresh produce was as a result of faecal contaminants in the irrigation water. It could therefore be concluded that a health risk is associated with the water from the Plankenburg and to a lesser extent, Eerste River when used as source of irrigation, thereby risking the transfer of potentially harmful organisms, present in the rivers as result of faecal pollution, to the surface of fresh produce. / AFRIKAANSE OPSOMMING: Suid-Afrika stuur tans af op 'n dreigende water krisis. Klimaatsverandering tesame met 'n spoedig groeiende bevolking het gelei tot 'n aansienlike vermindering in die land se varswaterbronne terwyl veranderende reënvalpatrone daartoe bygedra het dat talle boere al hoe meer afhanklik geword het van oppervlakvarswaterbronne as hul hoof-besproeïngsbron. Verstedeliking, armoede asook verouderde en onvoldoende infrastrukture het egter bygedra tot die besoedeling van baie van hierdie oppervlakvarswaterbronne. Gevolglik is meeste boere genoodsaak om klaar te kom met besproeïngswater van, nie net onaanvaarbare mikrobiese kwaliteit nie, maar dikwels water wat gekontamineer is met onbehandelde riool. Hierdie studie was gevolglik daarop gemik om die impak van die mikrobiologiese kwaliteit van besproeïngswater op die veiligheid van vars groente en vrugte te bepaal. Standaard mikrobiologiese metodes vir die bepaling van indikator organismes soos totale en fekale kolivorms, E. coli en enterococci asook potensiële patogene wat Salmonella, Listeria en Staphylococcus insluit, was gebruik om die mikrobiese lading by drie verskillende punte (P1, P2 en P3) in die Plankenburg en Eerste Rivier te bepaal. Chemiese parameters soos pH, alkaliniteit, konduktiwiteit en Chemiese Suurstof Behoefte was ook bepaal maar geen korrelasie kon tussen hierdie eienskappe en die mikrobiese besoedelingsvlakke getref word nie. Hoë konsentrasies fekale kolivorms en E. coli wat onderskeidelik vanaf 3.1 x 102 tot 7 x 106 kve.100 mL-1 en 2.3 x 102 tot 7 x 106 kve.100 mL-1 gestrek het en gereeld die voorgeskrewe riglyne van onderskeidelik ≤1 000 (WHO, 1989) en ≤4 000 kve.100 mL-1 (DWAF, 2008) oorskry het, was by al drie punte gevind. Hierdie resultate het gedui op fekale besoedeling wat gevolglik met 'n hoë gesondheidsrisiko geassosieer kon word. Hierdie risiko was bevestig deur die teenwoordigheid van talle potensiële patogene, soos Aerococcus viridans, Klebsiella, Listeria monocytogenes en Salmonella typhimurium, wat vanaf al drie punte geïsoleer was. Die oordrag van organismes vanaf die besoedelde riviere na vars vrugte en groente (groen bone en druiwe) was bepaal deur die mikrobiese lading in die Plankenburg en Eerste Rivier te vergelyk met dié verkry vanuit die besproeïngswater en vanaf groen bone wat besproei was met hierdie water. Fekale kolivorms, E. coli, Aerococcus viridans, Enterobacter aerogenes, Klebsiella, L. innocua, L. grayi, L. monocytogenes en Staphylococcus aureus was vanaf al drie die monster tipes geïsoleer. Hierdie resultate het gedui op eenderse mikrobiese populasies in al drie bronne en het daarom die moontlike oordrag van patogene bevestig. Die opbou van organismes as gevolg van veelvuldige besproeïngsessies aan die oppervlak van groen bone was bevestig deur die toename in fekale kolivorm konsentrasie vanaf 'n begin telling van nul tot 'n maksimum konsentrasie van 44 000 kve.100 mL-1. Laastens was mikrobiologiese bron naspeurbaarheidstegnieke soos multi-antibiotika weerstandbiedende profiele en die API 20E klassifikasie sisteem gebruik om individuele genotipe en fenotipe profiele van die 105 fekale isolate saam te stel. Numeriese klassifikasie sisteme was gebruik om die isolate op grond van ooreenkomste tussen hul individuele fenotipiese en genotipiese karaktereienskappe te groeppeer. 'n Hoë mate van ooreenkomstigheid sal dan daarop dui dat isolate van dieselfde besoedlingsbron afkomstig is en gevolglik die oordrag van organismes vanaf besproeïngswater na vrugte en groente bevestig. Onderskeidelik 93 en 98% van die fekale isolate het daarop gedui om weerstandbiedend te wees teen beide 5 en 30 μg Vancomycin. Die meerderheid isolate (82%) het ook 'n mate van weerstand teenoor Erythromycin (15 μg) en Ampicillin (25 μg) getoon met inhibisie sones ≤4 mm. Isolate was ook sensitief teenoor Ciprofloxacin (1 en 5 μg), Ofloxacin (15 μg), Ceftriaxone (30 μg) en Cefotaxime (5 μg). Hierdie antibiotikums was in staat om die groei van onderskeidelik 79.8, 93.3, 79.8, 88.5 en 71.2 % van die isolate te inhibeer. Alhoewel resultate 'n hoë mate van variasie tussen isolate van dieselfde spesie getoon het was dit nogtans moontlik om 35% van die isolate saam te groeppeer op grond van ooreenstemmende genotipe en fenotipe profiele. Meer as 'n derde van die fekale isolate wat vanaf die oppervlakte van die groente en vrugte geïsoleer was, was afkomstig vanaf fekale besmetting in die besproeïngswater. Die oordrag van potensieël patogene organismes vanaf besoedelde riviere na vars vrugte en groente tydens besproeïng was sodoende bevestig. 'n Hoë gesondheidsrisiko was gevolglik gekoppel aan die gebruik van water vanaf die Plankenburg Rivier, en in 'n minder mate die Eerste Rivier, as bron van besproeïngswater. / Water Research Commission / National Research Foundation

Made available in DSpace on 2014-08-20T14:33:06Z (GMT). No. of bitstreams: 1 Dissertacao_Carina_ Estrela_.pdf: 16751997 bytes, checksum: 57dab41429721d293278464eaa3be9b4 (MD5) Previous issue date: 2008-10-27 / The main economic activities developed at Turuçu-RS (Brazil) are the dairy cattle breeding, cultivation of temperate climate fruit, tobacco and red-hot chili pepper. Among the fruits, strawberry is a relevant crop which is providing worthy investment return for the farmers, generating income, employment, social inclusion and therefore rising quality of life of the farmers. Drip irrigation is one of the adopted technologies by the rural producers in the strawberry crop system. The irrigation water quality has an important role in this system due the potential to cause emitters clogging, reducing the equipment life time and irrigation uniformity. The effect of the water quality may very depending on factors as the kind of water source, local climate and the irrigation management employed by the farmer. This work intended to characterize the irrigation water sources in relation to their origin and to assess the spatial and temporal variability of the water quality utilized in the strawberry crop in 15 rural properties affiliated to the Association of Strawberry Producers of Turuçu-RS. Water samples were collected monthly at water supply for ten months. The water quality was evaluated in terms of its physical (suspended solids, dissolved solids and turbidity), chemical (pH, total iron, dissolved oxygen, electrical conductivity and hardness) and microbiological parameters (total and fecal coliform bacteria). These parameters were evaluated in relation to the hazard to cause damages to the drip irrigation systems and to their spatial and temporal distribution by means of box plot graphs. To characterize the irrigation water sources relating to their origin was employed a typology for grouping the sources based on the CONAMA (National Council for the Environment) Resolution 303/2002. In this manner, six sources were classified as Group 1, five as Group 2, three as Group 3 and one as Group 4. It was verified that the rural producers had no technical advice about reservoir construction or water withdrawal location. The spatial and temporal variability of the water quality analyzed presented different magnitude for the parameters. The dissolved solid concentration presented the greatest among physical parameters, and dissolved oxygen, followed by electrical conductivity among the chemical. In relation to the clogging hazard, the suspended solid concentration was the physical parameter that presented the greatest percentage of samples classified as of moderate and severe risk, while turbidity was classified as adequate for most samples. For the chemical parameters, total iron levels presented the greatest percentage of samples classified as of moderate and severe risk. For dissolved oxygen, the percentage of samples classified as inadequate was over 50% in six properties, and it was classified as adequate over 50% in six properties. For the pH parameter the clogging hazard was found low in ten water sources while electrical conductivity and hardness presented low risk for all samples. It was not detected the presence of total and fecal coliform bacteria in four and five water samples, respectively, along the studied period. / No município de Turuçu-RS as principais atividades econômicas desenvolvidas são a pecuária leiteira, a produção de frutíferas de clima temperado, de fumo e de pimenta vermelha. Dentre as frutíferas, destaca-se o morangueiro que tem propiciado aos produtores rurais, boa rentabilidade constituindo-se em instrumento de geração de renda e emprego, inclusão social e assim incrementando o padrão de qualidade de vida destes produtores. A irrigação localizada por gotejamento foi um dos incrementos tecnológicos adotados na produção do morangueiro. Neste sistema, a qualidade da água utilizada assume papel importante podendo afetar seu funcionamento causando obstrução de emissores diminuindo sua vida útil e comprometendo a uniformidade da irrigação. Baseado nisto, este trabalho teve como objetivo caracterizar as fontes de captação de água usada para irrigação quanto a sua origem e avaliar a variabilidade espacial e temporal da qualidade da água usada na produção de morangos em 15 propriedades, pertencentes à Associação dos Produtores de Morango do Município de Turuçu-RS. Para tal, foram coletadas, mensalmente, amostras de água das fontes de captação em cada uma das propriedades, durante um período de 10 meses, determinando suas características físicas (sólidos suspensos, sólidos dissolvidos e turbidez), químicas (pH, ferro total, oxigênio dissolvido, condutividade elétrica e dureza), e microbiológicas (coliformes totais e fecais). Estas características foram avaliadas quanto ao potencial de causar danos ao sistema de irrigação por gotejamento e quanto a sua distribuição espacial e temporal ao longo do período utilizando gráficos em caixa. Na caracterização das fontes de captação de água foram usadas as definições da Resolução CONAMA 303/2002 para identificar características semelhantes quanto a origem das fontes de captação resultando em seis fontes caracterizadas como Tipo 1, cinco como Tipo 2, três como Tipo 3 e uma como Tipo 4. A variabilidade espacial e temporal da qualidade da água apresentou magnitudes diferentes quanto aos parâmetros, sendo a concentração de sólidos dissolvidos a maior dentre os físicos e o oxigênio dissolvido, seguido pela condutividade elétrica dentre os químicos. Quanto ao potencial de risco a causar entupimento dos gotejadores, a concentração de sólidos em suspensão apresentou o maior percentual das amostras classificadas como moderado e severo, dentre os parâmetros físicos, sendo a turbidez da água classificada como adequada em onze fontes de captação. Dentre os parâmetros químicos, a concentração de ferro apresentou o maior percentual de amostras com potencial de risco moderado e severo, o oxigênio dissolvido apresentou seis propriedades com mais de 50% das amostras de água classificadas inadequadas e em outras seis mais de 50% das amostras classificadas adequadas. O pH da água de irrigação apresentou baixo potencial de risco, em dez fontes de captação, enquanto que, a condutividade elétrica e a dureza total apresentaram potencial de risco baixo em todas as amostras. Não foi detectada a presença de coliformes totais em quatro amostras de água analisadas e de coliformes fecais em cinco, ao longo do período estudado.

Soils in irrigated fields are impacted by irrigation water quality. Salts in the irrigation water may accumulate in the soil depending on amount of leaching, the quality of water and type of ions present. Salinity is an environmental hazard that is known to limit agriculture worldwide. The quality of irrigation water is thus of concern to agriculturists. More so is the impact it has on productivity. The objective of this study was to quantify the impact due to use of ground water of such quality, with respect to salinity, as found in Berambadi watershed of Southern India, under farmers‟ field conditions. Turmeric (Curcuma Longa L.) was used for the study, based on salt sensitivity, under furrow irrigation. Study sites were selected basing on quality of water, with respect to salinity, crop and irrigation method. Samples of both soil and water were collected from each site and analyzed in the laboratory. The samples were analysed for salinity, alkalinity, pH and Cations of Magnesium, Sodium, Calcium and potassium as well as Chlorides and Sulfates. In addition soil was analysed for texture and Organic matter content. Non destructive plant monitoring for Leaf area (Index), number of leaves and plant height was done up to 210 days from planting. Profile, up to 80 cm depth, soil moisture was monitored at six plots using TDR and surface, up to 6cm depth, soil moisture for all the plots using Theta probe. Potential yield was obtained using STICS 6.9 crop model while field yield was estimated from rhizomes average weight of three plants. For both potential and observed yield estimation, a plant density of 9 plants per M2 was used. The quality parameters in water were correlated to soil parameters and to crop growth and ultimate yield. Impact due to salinity was then identified and quantified using relative yield. Identified quality problems in terms of turmeric response were, salinity, alkalinity and pH there was significant positive correlation between irrigation water salinity and soil salinity. Some wide scatter was observed and could be indicative of irrigation management practices, soil texture difference and other local variations. Observed turmeric yield was significantly negatively correlated to soil salinity. There was a monotonically increasing gap between simulated and observed yield as salinity increased. The maximum observed yield was 71% of the potential. The highest impact due to salinity was observed at 2.1 dS/m amounting to 44 % yield reduction. Excessive chlorosis due to iron deficiency occurred at 24.5% as CaCO3 and pH 7.5. Irrigation water pH was normal as per the guidelines. Soil pH was not so varied; it ranged between 7.1-7.9 except for one site where it was 6. Within the 7.1-7.9 range there was no effect on crop and yield observed. Interaction of stress factors observed was between salinity and alkalinity. The other was rhizome rot disease. Loss of yield to salinity was significant but farmers have no specific plans to leach out salts nor do they have an idea that ground water quality can actually negatively impact productivity. Salinity in irrigation water was in the moderately saline range. While that in the soil was low to slightly saline but could increase given the management practices.

Thesis (MScAgric (Conservation Ecology and Entomology)--University of Stellenbosch, 2007. / Small farm dams (< 20 ha) in the Western Cape Province provide adequate water conditions for intensive cage production of rainbow trout (Oncorhynchus mykiss). A major environmental concern of cage aquaculture, however, is the high inputs of nutrients via commercial diets and the subsequent eutrophication of the water source. Eutrophication can result in the degradation of the general water quality (increasing pH levels, oxygen depletion, increased hydrogen sulphide and free ammonia) and shifts in the phytoplankton structure (increased biomass, single species dominance). Deterioration of water quality will affect the success of the fish farming enterprise as well as the performance of irrigation equipment by increasing the risk of clogging and corrosion. Water quality, phytoplankton and zooplankton compositions were monitored at four sites from June 2005 to November 2006 to determine the effects of cage culture on the farm dam environment, its associated biota as well as irrigation water quality. The distribution of nutrients, nitrogen and phosphorus, was mainly influenced by the stratification and mixing regime of the water bodies. Nutrient concentrations increased during the winter mixing period while in the summer months, they seem to settle to the lower part of the water column. Nutrient concentrations of production sites and reference sites were comparable except for the ammonia levels that were significantly higher at the production sites. Phytoplankton corresponded with nutrient availability resulting in high biomass during winter. In terms of biomass, phytoplankton was approximately two times more abundant in production sites compared to reference sites. Assemblage dominance by cyanophytes (Anabaena circinalis, Microcystis spp.) was found more often in production sites, while reference sites were dominated by dinophytes (Ceratium hirundinella, Peridinium spp.). Zooplankton biomass concurred with high phytoplankton biomass in winter. Zooplankton assemblages in production sites sustained much higher biomass. Effects of cage culture on irrigation water quality are evident from increased algal biomass and shifts in species composition. These results indicated that at its present production level, cage culture had impacts on the farm dam environment and irrigation water quality. The most significant evidence was given by increased plankton biomass and single species dominance in production sites. However, these findings can not solely be ascribed to the introduction of aquaculture as various other factors may also contribute to the water quality of these ecosystems.