Dissertations / Theses on the topic 'Winch and furrow irrigation'

[Abstract]: Sugarcane farmers in Bundaberg have had limited access to irrigation water over the last ten years. The district has the potential of growing 3.8 million tonnes of sugarcane. However, a series of dry seasons saw this reduce to 2.1 million tonnes in 2002. Compounding the effects of both dry seasons and limited water supplies has been a 30% reduction in the sugar price over this period. The irrigation requirement of sugarcane in the Bundaberg area is 8 ML/ha. The original allocated volume for sugarcane production in this area was 4.5 ML/ha (based on 1970 production areas). However, as the area under production has increased and announced allocations in each year has reduced, this allocation is now equivalent to an application volume of about 2 ML/ha A change from the traditional practice of full irrigation is required as water supplies become depleted. As there were no clear guidelines on how growers could respond to diminishing water supplies, this research investigated opportunities to fine tune irrigation practices and the performance of irrigation systems (ie. low cost solutions) that would assist growers to maximise sugarcane yield. A grower survey was initially conducted to identify current practice and opportunities for change. Field investigations focused on the performance of water winch and furrow irrigation systems, which make up 91% of the irrigated area in the district. As most of these application systems have insufficient capacity to meet crop demands opportunities to schedule irrigations were limited to start up after rain. Improvements in irrigation system performance were found to provide the greatest potential to increase sugarcane yield under conditions of limited water. Investigations identified that irrigation performance could be significantly improved through relatively minor adjustment. Field trials found that wind speed and direction significantly influenced the performance of travelling gun irrigators. Although growers were generally aware of the effects of wind, meteorological data suggested that the opportunity to operate water winches in low wind conditions is limited. Changing to a taper nozzle under moderate to high wind conditions will reduce the effect of wind on performance. This practice was found to improve the uniformity (measured by Christiansen’s Uniformity Coefficient, CU) by 16%. The grower survey indicated that there was no preference towards the use of taper nozzles in windy conditions. Additional trial work developed a relationship between the variation in water applied to the field through non uniformity and sugarcane yield. An 8% reduction in yield was determined for a 10% reduction in CU. This indicated that changing to a taper nozzle could potentially increase sugarcane yield by 15% in high wind conditions. Other settings, which also influenced uniformity, included lane spacing and gun arc angle Simple changes to the operation of furrow irrigation systems were also found to dramatically improve irrigation performance. Field measurements in combination with simulation modelling of irrigation events using SIRMOD II identified that current irrigation performance ranged in application efficiency from 45 to 99% (mean of 79%) and a distribution uniformity from 71 to 93% (mean of 82%). Both application efficiency and distribution uniformity were increased to greater than 90% and 84% respectively, except on a cracking clay soil. Improvements in application efficiency and distribution uniformity were achieved by adjusting furrow flow rate (cup size), turning the irrigation off at the right time (ie. just as it reached the end of the field) and banking the end of the field. Growers had a good understanding of the correct cut off time and were attentive to reducing run off through either banking ends or tail water return. However, growers had a poor understanding of the significance of furrow flow rate. Other opportunities to improve irrigation performance on high infiltration soils included alternate furrow irrigation and shallow cultivation practices which maintained compaction in the interspace and reduced infiltration. Soil moisture and crop growth measurements indicated that sugarcane yield could be maximised by starting the irrigation rotation earlier after rainfall (ie. at a deficit equal to the irrigation amount). These observations were modelled using the crop simulation model APSIM sugar to assess the strategy over a longer time interval and the influence of seasonal variation. Simulation modelling showed that final sugarcane yields were not sensitive to irrigation start-up strategies. Yields for the start-up strategies modelled varied by less than 5 tc/ha. This minor difference occurred as the crop yield was driven by the total amount of water available to the plant. The limited amount of irrigation water available to the plant (2 to 3 ML/ha) had only a minor effect on the water balance and no significant change to effective rainfall between strategies. The greatest difference in yield occurred between irrigation treatments when water was left over at the end of the season (9.2 tc/ha). Starting irrigation earlier after rainfall events (on a 14 day rotation) provided the greatest opportunity to use all of the available irrigation supply. By comparison, delaying the application of the first irrigation after rainfall resulted in some of the irrigation water not being applied in 30% of years.

This research examines the effects of furrow spacing on irrigation uniformity and efficiency. Laboratory and field experiments were conducted to obtain information on soil physical characteristics, furrow infiltration and water advance data in order to validate the theoretical results. A furrow infiltration model based on Richards' equation and a finite element technique is developed and used to predict infiltrated depths in the transverse and longitudinal directions relative to the furrow centerline and furrow inlet, respectively. The model predicted measured furrow infiltration in the field from the third irrigation but failed to do so for the first and second irrigations. Simulations of furrow irrigation in a hypothetical soil with various furrow spacings showed that cumulative infiltration is not affected by furrow spacing until the lateral wetting front reaches the imaginary vertical boundary located midway between two furrows. An analysis of uniformity and efficiency from predicted water distribution profiles from field irrigated furrows are conclusive in that the use of longitudinal water distribution profile alone is not enough to assess the performance of furrow irrigation. The transverse distribution of infiltrated depths which is a function of furrow spacing must be included in the analysis.

The effect of furrow spacing on infiltration should be determined in order to properly design an irrigation system. The blocked furrow infiltrometer (BFI) and the flowing furrow infiltrometer (FFI) methods were investigated for this purpose in two areas upon a precision field furrow. Three irrigations were performed in each method. The initial and final soil moisture contents (before and after irrigation), the furrow cross-section (before and after irrigation), the inflow volume and the furrow water surface elevations (during irrigation) were measured in each test furrow. Cumulative infiltration and infiltration rates were determined for each irrigation. The results indicate that the FFI test furrows infiltrated more water than did the BFI test furrows for the same infiltration time. The infiltration rates were higher in the FFI test furrows than in the BFI test furrows until they approach the basic intake rate. The infiltration rates were also higher during the 0.90 m spacing tests than during the 1.80 m spacing tests. The 0.90 m spacing test furrows infiltrated more water than did the 1.80 m spacing test furrows.

The effort to improve furrow irrigation design and management by use of mathematical models is hampered by the difficulty of obtaining infiltration parameters that adequately describe the infiltration process in furrows. This difficulty is related to the effect on infiltration of the variability of wetted width of a furrow with depth. Detailed field measurements of twelve furrow irrigations were used to develop infiltration parameters based on three different assumptions regarding the variation of wetted width with depth. These infiltration parameters were used as input into a mathematical model of furrow irrigation, SRFR. Comparison of measured advance times, water surface elevations and volume of water infiltrated with these values computed by SRFR indicates that SRFR gives consistent results based on the input parameters.

The overall objective of this study was to evaluate the performance of selected furrow irrigation models for field conditions in south-east Australia. The other important aspects which were examined during this study include: developing a methodology for estimating of infiltrating characteristics, assessing the applicability of the Manning and other similar equations for flows in furrow irrigation, investigating the variation of shape factor during irrigation developing methodology for estimation of recession time and exploring the sensitivity of the models to the input parameters. Field experiments were conducted at Walla Park in northern N.S.W. and on two selected paddocks at the University Farm, Richmond, in western Sydney,Australia, over a period of three years. The validity of the assumption that the shape factor of advancing water front during furrow irrigation varies between 0.7 and 0.8 was investigated using field data collected from irrigation events monitored in the study. It was found that the average values of the shape factor varied from 0.96 to 1.80 at Walla Park site, from 0.56 to 0.80 at Field Services unit paddock site and from 0.78 to 0.84 at Horticulture Farm paddock site. The value of shape factor was affected by uniformity of furrow cross section along the length, the value and uniformity of furrow slope, furrow length and infiltration characteristics of soil. This means it is difficult to recommend a typical value for the shape factor for a given field situation.The performance of the models for prediction of advance and recession characteristics and runoff were evaluated using different indices of performance. In general, it was found that the Walker-HD and ZI model was the most satisfactory for the field conditions encountered in this study. This finding can provide a basis for initiating work on developing design criteria and management strategies for furrow irrigation in south-east Australia.
Doctor of Philosophy (PhD)

[Abstract]: Furrow and border irrigation practices in Australia and around the world are typically inefficient. Recent advances in computer-based surface irrigationdecision support technology have the potential to improve performance, but have had little uptake. Despite considerable academic achievements with individualcomponents of the technology, the implementation of this knowledge into usable tools has been immature, hindering adoption. In particular, there has been littleprogress in encapsulating the different decision support components into a standalone system for surface irrigation. Therefore, the research problem addressed in this dissertation aims to develop a new decision support system for furrow and border irrigation aimed at increasing the usability of the technology, and improving decision making capabilities. Specifically the research hypothesis is:“That calibration, optimisation, and parameter analysis capabilities can be developed and integrated with an accurate and robust simulation model into a decision support system to improve furrow and border irrigation performance.”Six research objectives have been identified to support the hypothesis including: (RO1) investigate existing surface irrigation modelling technology to determine amodel and solution technique structure suitable for incorporating into a decision support system; (RO2) develop a robust reliable simulation engine for furrow andborder irrigation for automation within a decision support system under optimisation and systematic response evaluation; (RO3) investigate and develop parameter estimation (calibration) capabilities for the decision support system; (RO4) investigate and develop optimisation capabilities for the decision support system; (RO5) investigate and develop parameter response (design charts)capabilities for the decision support system; and (RO6) develop an objectoriented framework to combine the components developed in Research Objectives 2 to 5 with data management facilities and a graphical user interface.Successful completion of these objectives has resulted in the development of a decision support system for furrow and border irrigation featuring an automationcapablehydrodynamic simulation engine, automated full-hydrodynamic inverse solution, automated optimisation of design and management variables, and automated user-definable real-time generation of system response. This wascombined with a highly flexible object-oriented program structure and webbrowser-like graphical user interface. Each of these components represents a unique implementation of the required functionalities, differing from the established software packages (such as SIRMOD and WinSRFR) that use alternate technologies with no automation or optimisation capabilities.Development of the hydrodynamic simulation engine has involved the refinement of the commonly used implicit double-sweep methodology with the objectives ofachieving robustness and reliability under automation. It was subsequently found that only subtle changes and manipulations were required in much of thenumerical methodology, including derivation of simplified solution equations. The main focus of this research has targeted the computational algorithms that drivethe numerical solution process. Key factors effecting robustness and reliability were identified in a study of simulation operation, and treated through thesealgorithms. Validation was undertaken against output from the SIRMOD simulation engine, with robustness and reliability tested through tens of thousands of simulations under optimisation and automated system response evaluation.The calibration facilities demonstrated that the inverse-solution using the fullhydrodynamic model is a viable and robust methodology for the unique identification of up to three infiltration/roughness parameters. Two optimisationmethods were investigated during this research with objective-functions based upon either a volume-balance time-of-advance equation, or complete simulationsof the hydrodynamic model. A simple but robust optimisation algorithm was designed for this purpose. While the volume-balance method proved fast andreliable, its accuracy is reduced due to the underlying assumptions and simplistic model structure. The hydrodynamic method was shown to be accurate, althoughit suffered slow execution times. It was therefore decided to use the two methods in tandem during the solution process where the faster volume-balance method is used to provide starting estimates for the more accuratehydrodynamic method. Response-surface investigation for the advance-based objective function identified a unique solution when solving for three parameters.It was found that the automated unconstrained optimisation of design and management practices is limited to the selection of one solution variable (time to cut-off) due to non-unique multi-variable solutions. Nevertheless, the developed facilities provide a unique benchmarking of irrigation performance potential. This research has used the earlier-developed optimisation algorithm to automatesimulations using a prototype objective-function based upon user-defined weightings of key performance measures. A study of the response-surfaces ofdifferent configurations of the objective-function identified parabolic ridges of alternate solutions, so, in practice, the optimisation process simplifies down tooptimising only one parameter: time-to-cutoff. It was also recognized that the performance-based objective functions are highly sensitive to numerical discretisation inconsistencies that occur between simulations, which impede solution convergence.The highly customisable, automated, system response evaluation facilities developed in this research offer potential as both a research and practitionertool, capable of multidimensional analysis of irrigation systems subject to temporal and spatial infiltration variations. A preliminary study demonstrated theimportance of infiltration variation on irrigation decision-making, and provided initial guideline layout designs that combined the effects of variable infiltrationand three decision variables using a fixed management strategy of minimising runoff. A limited range of response outputs for a fixed management objectivenegated the potential benefit of visualising a large number of dimensions. Nevertheless, this study provided direction for the subsequent software development with recommendations including: representing system outputs ascontours and iso-curves, rather than by the chart axes; representing different infiltration conditions in separate design charts; allowing the user to assignvariables to each chart axis; and representing only two decision variables in each chart.Finally, the simulation, calibration, optimisation and parameter analysis components were combined with a database and graphical user interface todevelop the FIDO (Furrow Irrigation Decision Optimiser) decision support system. There were three focus areas during this marriage of components; firstly, anobject-oriented structure was developed to accommodate program elements concentrating on separating the graphical user interface components from other task related objects for flexible future development; secondly, a database wasdeveloped using XML-based technologies to store property, paddock, event and model information; and thirdly, a user-friendly graphical user interface was created with web-browser-like functionality. The software design evolved through many different prototypes with its current design being heavily influenced from the successes and mistakes of the previous attempts.This work represents the first coordinated attempt to develop a decision support system for furrow irrigation linking a database, simulation engine, calibrationfacilities, optimisation facilities, and parameter analysis capabilities. A major feature of this work is that all components of the system have been developedfrom first principles using an object-oriented structure, with the primary goal of implementation into a decision support system. This research has contributed tothe development of a professional-quality software package to improve the decision-making capabilities of researchers, irrigation consultants, and irrigators.

The 1985 and 1986 Cotton Reports have the same publication and P-Series numbers.
The objective of this experiment was to evaluate the potential of applying herbicides in the irrigation water during a furrow irrigation as an alternate method of herbicide application in cotton. Further research is needed to study this method of applying herbicides. If a program could be designed for the Arizona cotton grower, it would help reduce production costs. However before this method can be recommended the environmental impact of such a treatment must be investigated to prevent jeopardizing currently labelled herbicides in cotton.

A newly installed subsurface drip system was compared to a conventional furrow-irrigated cotton production system in the Marana Valley in 2000. Regular measurements included soil moisture, flower tagging, general plant growth and development measurements, and lint yield. Results indicate that an increase in lint yield of approximately 250 lbs. lint/acre was obtained under the drip irrigation system. Approximately 1/3 less irrigation water was used under the drip irrigation system. Pounds of lint produced per acre-inch of water applied provide the most dramatic results. In the furrow-irrigated system approximately 25 lbs. of lint was produced per inch of water applied while the drip system ranged from 70-80.

The present study analyses the waters of Kilimanjaro Region, Tanzania, conceptualised as a waterscape constituted by material, institutional and ideational aspects. It draws on studies of the water management and the historical geography of hill furrow irrigation systems, based on 16 months of fieldwork. Hill furrow irrigation systems are operated by groups of farmers who continue to use and develop long-standing traditions. Their practices and technology are of relevance to debates about indigenous intensive agricultural systems in Africa, concerning their emergence, sustainability and prospects for development. Groups of self-organised irrigators and their practices are targeted by several development initiatives, in water management seeking to control their water use, and in irrigation redevelopment aiming to replace existing technology and organisation. These concerns define the need for improved knowledge of the hill furrow irrigation systems of Kilimanjaro. The main objective of this thesis is to contribute knowledge of water management and water use in hill furrow irrigation in Kilimanjaro Region. In order to achieve this objective, research proceeds along two lines of enquiry. The first concerns water management, where the study seeks to analyse and describe the operation, water use, tenure and management in hill furrow irrigation schemes by groups of farmers. The study seeks to analyse the ideas and implementation of initiatives in water management for the Pangani River Basin targeting these systems. The second line of inquiry is the historical geography of irrigation and changes in water use. Here, the study seeks to develop methods drawing on written and oral sources in order to examine changes in irrigation from a regional and long-term perspective. This will permit testing and reconsideration of dominant perceptions of hill furrow irrigation and its water history, and form the basis for a discussion of the explanation of change in irrigated agriculture. I maintain that the approaches to water issues employed in this thesis and elsewhere can be analysed through different conceptualisations of the waterscape, encompassing not only the perception and representation of water issues, but also the material and institutional aspects of the waterscape. Aridity or water shortage does not speak for itself; water problems and their prescribed solutions are situated knowledges of the waterscape, and are socially constructed within specific contexts. Material aspects are addressed as a question of how and why these systems have changed from a regional and historical perspective. This is relevant not only as a contribution to the study of the development of intensive agriculture, but also in order to test dominant perceptions of the hill furrow and its water history that are used to guide policy and interventions in hill furrow irrigation. Institutional aspects are examined as a question of the local organisation of these systems in terms of their operation, water use and tenure arrangements. Further, these aspects are addressed through the analysis of ideas, implementation and experience with water policy and institutional reform targeting hill furrow irrigation systems, influenced by global water discourse and actors. The thesis consists of five research papers and a synthesis. The latter describes the methodological approach, which combines qualitative and some quantitative analysis of various forms of interview data with participant observation from fieldwork in rural Kilimanjaro and engagement with actors in the water sector through interviews, conversations and workshops as well as written sources. Approaches to the explanation of change in irrigation are reviewed and some implications for irrigation in the region discussed. Approaches to the organisation of irrigation are reviewed, demonstrating that this is an enduring theme in social science, related to broader debates about the institutions of society. Working with an inclusive conception of institutions (and hydraulic tenure), the study describes how hill furrow schemes are organised, either through more formal groups, often with elected leadership, or through a neighbourhood and lineage-based model under the leadership of a furrow elder. The local organisation of water use according the latter type is examined through a case study, which describes it as embedded rather than a strong single-purpose organisation. Theoretical and methodological triangulation is applied, and the organisation studied at a normativeinstitutional level, but also in terms of interaction and access to water for different social groups. A series of initiatives in water management for the Pangani River Basin came in the wake of a hydropower redevelopment project completed in 1995 led by the Norwegian Agency for Development Co-operation (NORAD). The initiatives were related to a wider water policy process in Tanzania. They drew inspirations from a global water management discourse, which is analysed in terms of the influence of ‘state-centred’, ‘market-based’ and ‘community-based’ approaches to improved water management, related to development ideologies. A strategy of river basin management was developed from the 1990s, seeking to establish water licences under statutory law as the only legitimate basis for access to water, to introduce volumetric water pricing as an instrument of demand management, and to curtail water use by the construction of ‘control gates’ in furrow intakes. The process of implementation is analysed as a meeting between a ‘modern’ water management system and an ‘indigenous’ water management system. It was characterised by non-cooperation and conflict, not only over water as a resource, but over norms of proper water management, such as over the issues of water pricing and custom as a basis for legitimate water use. Change in irrigation as water use (and land use) change is addressed as a methodological and empirical question. Oral political history indicates the practice of irrigation in late 17th century Marangu, while the history of sedentary patrilineages as the central institution in irrigation management shows the expansion of the system in upland Marangu in the 19th century. The establishment of irrigation schemes in the 19th century can be related to dry season cultivation of finger millet, a crop that was phased out with the increase in agroforestry in the highlands and expansion of arable cultivation of maize in the foothills in the early to mid-20th century. Surveys made for administrative purposes and contemporary reports are analysed to test two hypotheses about changes in irrigation. The results show that the dominant understanding – that the extent of irrigation is a result of late 20th century increases in population – is false and needs to be moderated. A competing thesis of decline in irrigation fits the development only in limited areas and underestimates the dynamic vitality of the system. On the basis of this regional and long-term diachronic analysis, a hypothesis of restructuring is put forward, where a decline in the number of schemes in the densely settled highland areas since the 1930s has been offset partly by an increase in irrigation in new areas in the foothills and lowlands and partly by an increase in scale. It is argued that change in irrigation is not determined by a single factor such as population, but that technological change and the intensification process and changes in political economy (in terms of market, economic policies, and development planning) have to be considered. Ideas of water are explored in terms of ideas of improvement in water management and local perceptions of water relevant to the operation of irrigation. The analysis suggests that the water management reform process is influenced by development ideologies in the global water management discourse as well as a national tradition that can be described as technocratic. Its implementation was guided by notions and interpretations of a water crisis. Local ideas of water management differ from those associated with the initiative, which in turn influenced how water management was contested.

There is a regulatory tension within wastewater treatment, between the requirement to meet tightening consents and the need to reduce the carbon footprint of treatment processes. With 75% of wastewater treatment works serving populations of less than 2,000, low-energy tertiary treatment options suitable to small rural works need to be developed. One option that lends itself particularly well to small works is land-based wastewater treatment (LBWWT). The aim of this research was to evaluate the role of LBWWT in the UK water industry and investigate the impact ridge-and-furrow enhanced microtopography (MT) may have upon a particular type of LBWWT - slow-rate (SR) infiltration. This was achieved through meeting three objectives. Firstly, the use of LBWWT was reviewed and assessed. Secondly, the impact of ridge-and-furrow enhanced MT upon the vegetation diversity and nutrient removal of a SR- LBWWT was established by means of a three year field trial. Finally, the cost- effectiveness of SR-LBWWT and the impact of ridging and furrow irrigation upon cost-effectiveness were evaluated using Cost-Effectiveness Analysis (CEA). The first objective comprised of a review of the historical and current use of LBWWT, a review of the relevant changing legislation to identify what may be required of LBWWT and an assessment of LBWWT’s potential to meet these requirements. The result of the evaluation found that, based upon the literature, SR-LBWWT is ‘fit-for-purpose’ as tertiary treatment for small treatment works. To meet the second objective, a SR-LBWWT system trial was established at a small wastewater treatment works in Knowle, Hampshire. The trial consisted of three clay-loam grass plots irrigated with secondary treated effluent. There were two configurations of trial plot - flat and ridge-and-furrowed. Effluent (sub- surface soil water) nutrient concentrations were monitored as was vegetation diversity. In addition a number of physical, hydrological and biogeochemical parameters were monitored and hydrological modelling carried out. Mean nutrient removal performances of 90% for ammonia, 72% for nitrate, and 91% for phosphate were observed with the ridge-and-furrowed plot. Ridging and furrow irrigation was found to not have a significantly detrimental effect upon the trial plots’ removal performance for ammonia, nitrate or phosphate. Extrapolation modelling suggested, however, that this would not be the case for LBWWT systems on predominantly clay or sand soils. Ridging and furrow irrigation was found to have a statistically significant positive effect upon the vegetation diversity of the LBWWT trial plots; with mean final year Shannon-Wiener values of 0.96 and 0.69, for the ridge-and-furrowed and non-ridged plots, respectively. For the final objective, analysis found that SR-LBWWT are cost-effective when compared to horizontal sub-surface flow constructed wetlands (HSSFCW), an established low-energy treatment option. Mean cost-effectiveness ratio values of £208.5 and £262.7 per % effectiveness were observed for LBWWT and HSSFCW, respectively. Following the field trial CEA was extended to include ridge-and-furrowed SR-LBWWT systems. This found that ridging and furrow irrigation improves the cost-effectiveness of SR-LBWWT serving small populations, reducing the mid cost-effectiveness ratio to £193 per % effectiveness. This is a result of the cost-reducing effect of ridge-and-furrowing over laser-level grading; and based upon the findings of the trial that ridging and furrow irrigation can be achieved (in clay-loam soil slow-rate systems) without significant detriment to the water treatment effectiveness of LBWWT. The main conclusions of this thesis are: that SR-LBWWT has a role to play in the UK water industry, as tertiary treatment for small wastewater treatment works. That SR-LBWWT is cost-effective in relation to HSSFCW. That ridging and furrow irrigation increases that cost-effectiveness by reducing the construction and operational costs. That ridging and furrow irrigation can be employed without significant detriment to a SR-LBWWT system’s water treatment performance. And finally, that ridging and furrow irrigation can have a positive impact upon the establishment vegetation diversity of a SR-LBWWT system.

This thesis is about the Chagga traditional furrow irrigation system locally known as mfongo, practiced on the southern slopes of Mount Kilimanjaro. This is one of the Africa’s pre-colonial islands of intensive agricultural practicing areas. The study traces the relationships between communities and water irrigation from the late pre-colonial era (c. AD 1750) to the present day. This assessment was carried out within the framework of historical ecology with the purpose of understanding the historical trajectories of patterns and processes on this specific ecosystem and landscape, and how these have helped to building lasting socio-ecological resilience. The reserch questions are based on: the mfongo irrigation management and practice, strategies in the past and present responsible for the coping and adaptation capacities, how water management relates to the physical landscape transformation, cultural practices, livelihoods and heritage, and how the system can help to enhance transformation. Written sources, interviews and participatory observation were used to collect information to address the questions. The analysis shows that coping, adaptive and transformative responses have long been characteristic of dealing with vulnerabilities. I argue that coping capacities inherited from the long term historical knowledge and practices will continue to be essential in sustaining resilience in social ecological systems as communities endeavours to minimise vulnerabilities. I hope that these analyses of vulnerability and resilience in the Chagga mfongo water management system will help inform and influence policy makers when it comes to ecosystem and landscape management and rural development in the Kilimanjaro region. Furrow irrigation, indigenous knowledge, social-ecological system, coping capacity, adaptive capacity, resilience, transformation.

Orientador: Roberto Testezlaf
Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Agricola
Made available in DSpace on 2018-08-06T12:49:54Z (GMT). No. of bitstreams: 1 Gomes_EderPereira_D.pdf: 2568175 bytes, checksum: 5e0ee1aa19ad6060b3562bc9ef0c7b3e (MD5) Previous issue date: 2005
Resumo: A irrigação, na forma que vem sendo realizada na tomaticultura da região de Campinas, SP, tem proporcionado sérias restrições ambientais. O presente trabalho avaliou alternativas de mudanças tecnológicas na irrigação da tomaticultura da região de Campinas, buscando uma solução sustentável, viável economicamente e com eficiente uso da água, instalando em uma área experimental, diferentes sistemas de irrigação empregados na tomaticultura da região (sulcos, sulcos abastecidos por mangueira e gotejamento). As parcelas experimentais foram dispostas em delineamento de blocos ao acaso com quatro repetições. Comparou-se no experimento, a eficiência de uso da água, os parâmetros de eficiência e de uniformidade de irrigação, a produtividade e a qualidade dos frutos de tomate e o efeito de cada sistema de irrigação no valor da cobrança da água e no custo de produção. A irrigação por sulcos, por ser o sistema predominante na região, foi utilizada como testemunha (sem interferência no manejo de irrigação), enquanto os outros sistemas, foram avaliados como alternativas tecnológicas. Mediante os resultados obtidos pode-se afirmar que não houve diferenças significativas de produtividade entre os tratamentos, pois todos ofereceram condições ideais de umidade no solo. Entretanto, as eficiências de uso da água foram distintas, sendo iguais a 24,1 kg.m-3, 71,5 kg.m-3 e 112,8 kg.m-3, respectivamente para sulcos, sulcos abastecidos por mangueira e gotejamento. A irrigação por sulcos obteve baixa eficiência de aplicação, em torno de 28%, com perda por percolação profunda superior a 70%. Na irrigação por sulcos abastecidos por mangueira e gotejamento, os valores de eficiência de aplicação foram superiores, sendo iguais a 85% e 87,8%, respectivamente, com perdas por percolação menores, 15% e 12,2%, respectivamente. Em todos os sistemas de irrigação, a cobrança da água exerceu pouca influência no custo de produção, com valores iguais a 0,14% (R$40,80), 0,04% (R$13,32) e 0,03% (R$8,25), respectivamente para sulcos, sulcos abastecidos por mangueira e gotejamento. A irrigação por gotejamento elevou o custo de produção em 3,5% (+R$1041,89), enquanto a irrigação por sulcos abastecidos por mangueira reduziu o custo de produção em 1,1%(-R$330,08). Diante dos resultados, chegou-se à conclusão que a irrigação por sulcos abastecidos por mangueira é opção mais sustentável de mudança tecnológica, pois demandou menor investimento, diminuiu o custo de produção e o consumo de água, enquanto a irrigação por gotejamento contemplou somente o último aspecto, a redução do consumo de água
Abstract: Searching for a sustainable yield, economically viable and water efficient use, the objective of this study was to evaluate changes in irrigation technologies used in fresh-market-tomatoes crop. Three different irrigation systems (furrow, furrow supplied by hose and drip) were installed in the same farm to compare water application uniformity and efficiency, to estimate crop yield and fruits quality and to analyze its effects on water and production costs. The irrigation systems were select based upon the facts that furrow is a most utilized system in the region, the furrow supplied by hose and drip irrigation are recent alternatives market technologies for the farmers. The results showed no significant differences in yields and fruits qualities among the evaluated irrigation systems. The drip irrigation system showed higher water use efficiency. The furrow irrigation system showed application efficiency of around 28%, with deep percolation losses of 70%. The furrow supplied for hose and drip irrigations systems had applications efficiencies of 85% and 87.8%, respectively with deep percolation losses of 15% and 12.2%, respectively. In all the irrigation systems, the water cost had no significant effect the total production cost, representing only 0.14%, 0.05% and 0.03%, for furrow, furrow supplied by hose and drip irrigations systems, respectively. The change to drip irrigation system increased the production cost yield in 3.5%, while furrow supplied by hose reduced it in 1.1%. The furrow irrigation system supplied by hose showed the most sustainable technical option to change from the traditional furrow irrigation for the farmers, being able to reduce the production cost and the amount of water with less investment
Doutorado
Agua e Solo
Doutor em Engenharia Agrícola

O solo Mediterrâneo caracteriza-se por possuir, entre cerca de 35 e de 75 cm de profundidade, um horizonte B compacto, resultante da argila ai acumulada, vinda das camadas superiores do perfil. Esta característica limita a infiltração e condiciona o processo de rega, ao mesmo tempo que reduz a permeabilidade ao ar e à água e a capacidade de penetração das raízes e, dai, a capacidade utilizável do solo. A baixa permeabilidade do horizonte B resulta facilmente em excesso de água nos horizontes superficiais, aumentando a instabilidade estrutural e a susceptibilidade do solo à erosão. A subsolagem pode produzir uma alteração significativa nas condições fisicas do solo, pela criação de fracturas na camada compactada, proporcionando condições que permitam melhorar a circulação do ar e da água no perfil do solo e facilitar o aprofundamento radical das plantas, resultando isto num aumento da fertilidade potencial do solo. Pode ser bastante importante introduzir esta operação no esquema de mobilizações praticado em solos Mediterrâneos do Alentejo, onde 40% dos solos são desta natureza. A importância será ainda maior nas zonas de regadio, onde a subsolagem pode contribuir substancialmente para um sistema de uso do solo sustentável, quer do ponto de vista económico, quer do ambiental. Fez-se um ensaio de subsolagem num campo organizado em terraços de contorno, forma organizativa adequada ás condições de terreno ondulado, que são as habituais nos solos mediterrâneos do Alentejo. Estabeleceram-se duas modalidades de subsolagem: uma profunda, SP, feita com subsolador-vibrador actuando a 75 cm de profundidade e passando a intervalos de 1,5 m; outra ligeira, SL, feita com o "ripper" de um tractor de rasto contínuo, actuando a 40 cm de profundidade e passando a intervalos de 0,75 m. Cada uma das modalidades foi praticada em um dos terraços, com cerca de 260 m de comprimento e 30 m de largura mínima. As modalidades foram comparadas entre si e com uma modalidade testemunha, estabelecida em outro dos terraços, onde se praticou o sistema tradicional de mobilização do solo. Instalou-se uma variedade para grão da cultura de milho e fez-se a rega por sulcos, utilizando-se um sistema de cabo-rega automatizado, processo bem adequado ao terreno organizado em terraços de contorno. Os parâmetros pedológicos avaliados foram: densidade aparente, condutividade hidráulica, resistência à penetração, desenvolvimento das raizes (técnicas do mini-rizotrão e do mapeamento radical) e evolução do perfil de humidade com as regas. Avaliaram-se algumas regas, tendo-se determinado para cada uma a equação de infiltração pertinente e as qualidades (eficiência e uniformidade). No fim do ciclo cultural, determinou-se a produção, em termos de grão e da parte aérea da biomassa. Os resultados evidenciam uma acção muito significativa da subsolagem profunda sobre as propriedades fisicas do solo, que se reflectem em diferenças, também muito si-gnificativas, da infiltração, das qualidades da rega e da produção, relativamente quer à modalidade testemunha, quer à de subsolagem ligeira. As diferenças entre esta e a testemunha foram menos significativas, sugerindo menor interesse desta modalidade de subsolagem, apesar do seu menor custo de execução, relativamente à de subsolagem profunda. ### Abstract - The Mediterranean soil is a Luvisol soil with a compact B horizon located at a depth of about 35 to 75 cm, made up by the accumulation of clay that migrated from the upper layers. This compact layer limits the movement of water, air, and roots into deeper layers of the soil profile. Therefore, the water holding capacity is reduced, and a weak structure and high erodibility occur along with poor drainage in the surface layers, conditioning the irrigation process. Subsoiling is expected to change significantly such harsh physical conditions. Especially under irrigation, subsoiled soils can be made more productive and less susceptible to erosion than those under normal tillage, thus better supporting a sustainable irrigated agriculture. An experiment was carried out on a contour terraced field, with two subsoiling treatments: deep subsoiling, SP, and light subsoiling, SL. For the SP treatment, a vibrating subsoil plough worked at a depth of 0.75 m with 1.5 m within plough passages; for the SL treatment a tractor ripper was used as a subsoil plough, working at a depth of 0.4 m and a 0.75 m width between plough passages. Each treatment was applied to a contour terrace of about 260 m in length and 30 m in widh. The two treatments were compared to each other and also to a standard conventional tillage, carried out on another terrace. A grain maize crop was sown and furrow irrigated by a cable-irrigation system. For comparison between treatments, bulk density, hydraulic conductivity, resistance to penetration, root growth, and soil water content patterns were obtained. Three irrigation events were evaluated, and the infiltration equation pertinent to each irrigation event was determined, as well as the parameters of efficiency and uniformity. At the end of the crop cycle, aerial biomass and grain yields were also evaluated. soiling. Compared to both the standard and the SL treatments, the results of deep subsoiling treatment (SP) show a very significant effect on improving the soil physical properties and root growth, as well as on infiltration and the irrigation evaluation pa-rameters. The SL and the standard treatment differences were sometimes not significant, which suggests that light subsoiling is not an interesting technique, despite its low cost and ease of doing.

Orientador: Roberto Testezlaf
Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Agricola
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Resumo: A utilização do sistema de irrigação por sulcos por tomaticultores, vem determinando um consumo excessivo de água na exploração da cultura e tornando uma preocupação financeira para os produtores do tomate de mesa com a criação de uma legislação onde se prevê a cobrança pela captação e uso da água. O objetivo do presente trabalho foi proceder a avaliação da demanda de recursos hídricos na produção do tomate de mesa pelo sistema de irrigação por sulcos, simulando o impacto da cobrança de água no custo de produção do tomate de mesa. Os eventos de irrigação de uma propriedade produtora de tomate de mesa localizada no Município de Estiva Gerbi/SP, foram monitorados durante a safra de 2003. A lâmina de irrigação aplicada pelo produtor foi estimada a partir da vazão do sistema e do tempo de irrigação, sendo a umidade do solo monitorada através de três baterias de tensiômetros e os valores da evapotranspiração de referência, determinados pelos dados coletados em uma estação meteorológica automática instalada na propriedade. A determinação do custo de produção foi realizada utilizando-se o modelo proposto pelo Instituto de Economia Agrícola/SP, que permitiu, também, a simulação do custo para diferentes valores de eficiência de irrigação. A lâmina total de água aplicada pela irrigação foi de 1.326 mm, o que resultou em uma baixa eficiência de uso de água (EUA) de 4 Kg/m3 e uma eficiência de aplicação da água (EA) de 32%. O custo da cobrança da água representou 0,4% do custo de produção, considerado pouco significativo para o valor total de produção. Portanto, com os resultados obtidos, pode-se concluir que a política de cobrança pelo uso da água certamente não inibirá a continuidade do uso excessivo dos recursos hídricos dessa atividade agrícola. Entretanto, a demonstração ao produtor do custo associado ao bombeamento poderá contribuir para a sua conscientização e a recomendação do uso do tensiômetro como uma ferramenta prática e útil, auxiliaria a realização do manejo apropriado da irrigação por sulcos e obtenção da redução no seu custo de produção
Abstract: The use of furrow irrigation system by tomato farmers determined an excessive water use in the crop production. As a result of a state legislation proposal to tax the water use the tomato growers being to have a new financial concern. The objective of the present work consisted to evaluate the water demand in the production of fresh market tomato irrigated by furrow system and to simulate the impact of the water taxation in its production. The irrigation events of a fresh market tomato farm located in the City of Estiva Gerbi, SP, were monitored during the 2003 harvest. The depth of irrigation applied by the farmer was estimated from the outflow of the pump system and the time of irrigation. The soil moisture were monitored through three batteries of tensiometer and the values of the reference evapotranspiration were determined using the data collected in an automatic meteorological station installed in the property. The determination of the production cost was made by using the model proposed for the Agribusiness Economic Institute/SP, which also allowed the simulation of the production cost for different values of irrigation efficiency. The total irrigation depth used in the production was 1,326 mm, which resulted in a low water use efficiency (WUE) of 4 Kg/m3 and water application efficiency (AE) of 32%. The water tax payment represented only 0.4% of the total production cost, considered not significant for the total value of production. Therefore, based in the results, it can be concluded that the taxation policy of the irrigation water usage certainly will not restrain the continuation of the excessive use of the water resources in this agricultural activity. However, the demonstration to the growers of the values associated to the pumped cost can contribute to the problem awareness and the recommendation of tensiometer use as practical and useful tool to the irrigation water management in furrow irrigation would help to obtain a reduction in production cost. Key words: production cost, water taxation, water demand, application efficiency
Mestrado
Agua e Solo
Mestre em Engenharia Agrícola

Devido à escassez de recursos hídricos, efluentes de plantas de tratamento de águas residuárias têm sido reutilizadas ou recicladas em todo o mundo. Em algumas regiões áridas e em particular em regiões semi-áridas, o reuso de água tem sido reconhecido como um valioso recurso. Entretanto, dependendo da natureza do uso, surgem preocupações sobre potenciais riscos associados à presença de patógenos e contaminantes e a saúde humana. Uma grande variedade de contaminantes orgânicos pode estar presente nos esgotos domésticos e ser recirculado pelo ambiente. Alguns desses compostos apresentam o potencial de desregular as funções normais do sistema endócrino dos organismos e assim, causar efeitos adversos sobre a saúde humana. Entre esses compostos, incluem-se os hormônios estrógenos naturais e sintéticos. Nesse trabalho, desenvolvido na Estação Experimental de Tratamento de Águas Residuárias Urbanas do IPH/UFRGS, localizada nas dependências da ETE São João – Navegantes / DMAE / Porto Alegre / RS, foi investigada a ocorrência de hormônios naturais e sintéticos em grãos de milho cultivados por processo de irrigação por sulcos com efluentes domésticos tratados. O método analítico utilizado para quantificação dos hormônios de interesse foi a cromatografia líquida de alto desempenho (HPLC). Os resultados obtidos confirmam a presença de hormônios naturais e sintéticos no esgoto bruto e nos efluentes tratados, mas em concentrações extremamente baixas e não indicam processo de transferência ou acúmulo desses contaminantes para os grãos de milho.
Due to the scarcity of fresh water resources, effluents from wastewater treatment plants have increasingly been reclaimed and reused around the world. In some arid and semiarid regions, in particular, reclaimed water has been recognized as a valuable resource for non-potable use such as irrigating crops. However, depending on the nature of application, there is concern about potential risks associated with pathogens and organic contaminants to the environment and human health. A wide range of organic contaminants may be present in wastewater and the environment receiving it. These include natural and synthetic estrogens have the potential to disrupt the normal function (s) of endocrine systems in organisms and thus causing health effects on wildlife and humans. In the present work, developed at “Estação Experimental de Tratamento de Águas Residuárias Urbanas do IPH/UFRGS”, located on the ETE São João – Navegantes /DMAE / Porto Alegre /RS, was investigated the occurrence of natural and synthetic hormones in corn’s grain (Zea mays) cultivated by furrow irrigation of treated domestic effluents. The analytic method used for the hormones quantification was the High Performance Liquid Chromatography (HPLC). The results confirm the presence of natural and synthetic hormones on the untreated and treated effluents, although with a very low concentration and not indicated accumulation of this one to the corn’s grain.

Orientador: Roberto Testezlaf
Tese (doutorado) - Universidade Estadual de Campinas. Faculdade de Engenharia Agricola
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Resumo: No Brasil, a produção de tomate de mesa é realizada, em sua maioria, utilizando-se a irrigação por sulcos, apesar da baixa eficiência e o potencial de contaminação dos recursos hídricos apresentados por esse sistema. Assim, o presente trabalho teve como objetivo quantificar os impactos da irrigação por sulcos, utilizada na cultura de tomate de mesa, que possam comprometer a disponibilidade hídrica da bacia hidrográfica do Rio das Pedras, situada nos municípios de Mogi-Guaçu e Estiva Gerbi, SP. Foram avaliados parâmetros relacionados com o desempenho da irrigação em uma propriedade agrícola, onde foram monitoradas: lâmina de irrigação, água percolada, armazenamento de água no solo, evapotranspiração de referência, escoamento superficial e precipitação. Com o intuito de expressar de forma objetiva e integrada as alterações da qualidade da água na bacia hidrográfica, estabeleceu-se um índice de qualidade da água, a partir da determinação dos níveis de concentração de oito contaminantes físicos e químicos presentes na água superficial. Para a avaliação dos impactos na qualidade da água, foram realizadas coletas de amostras de água em seis pontos ao longo da bacia durante treze meses, que permitissem a identificação do carreamento de nutrientes e de sedimentos provocados pela erosão. De acordo com os resultados obtidos a eficiência de irrigação na propriedade foi da ordem de 26%, considerada baixa quando comparada a outros sistemas de irrigação. As perdas por percolação foram estimadas em 11%, aproximadamente, as perdas por escoamento superficial no sistema calculado em torno de 1,5%, e as perdas por condução em 61%. Desta forma as perdas totais foram de aproximadamente 74%. No entanto, o uso de sulcos curtos e o manejo realizado na irrigação geraram valores aceitáveis de uniformidade de distribuição de água no solo. Apesar disso, a irrigação por sulcos, da maneira que é realizada, foi considerada ineficiente e com potencial para a redução da disponibilidade dos recursos hídricos. Quanto à qualidade da água, observou-se por meio do índice de qualidade de água (IQA), condições de deterioração na bacia do Rio das Pedras, relacionados com a produção do tomate de mesa na bacia. Observou-se também a presença de NH3-N e NH3, originados no processo de fertilização utilizado na cultura. A principal conclusão desse estudo foi a comprovação da ineficiência da irrigação por sulcos praticada pelo produtor, com perdas excessivas de água que afetam a disponibilidade de água da bacia pela presença de contaminantes físicos e químicos
Abstract: Furrow irrigation is the mostly used system in the production of fresh market tomato in Brazil, although, its low application efficiency and the potential to contaminate water resources. The object of this study was to quantify the impacts of furrows irrigation management in the tomato crop, which can compromise the water availability (quantity and quality) at the Rio das Pedras Watershed, located in the cities of Mogi-Guaçu and Estiva Gerbi - SP. It were evaluated the irrigation performance parameters that could affect the readiness of watershed water resources. The following irrigation components were monitored: irrigation depth applied, furrow runoff and water percolation, soil water storage, reference evapotranspiration, and precipitation. Using the concentration levels of eight physical and chemical superficial water contaminants in six sample points during thirteen months, a water quality index was estimated to express the alterations of the watershed water quality. The water index was used to identify the nutrients and sediments transported inside the watershed. The results showed that the irrigation efficiency was around 26% in the farm; value considered low when compared to others irrigation system. The percolation loss was approximately 11%, and the runoff near to 1.5%. The water conduction loss (pipe and soil channels) was estimated in 61%, resulting in an overall irrigation loss of approximately 74% in the farm. However, the irrigation management applied in short length furrows generated acceptable water distribution uniformity. The water quality index showed agricultural chemical contaminations along the watershed, highly related to the fresh market tomato production, the major agricultural exploration in the watershed. It was observed the presences of NH3-N and NH3, mainly originated in the fertilization process used in the tomato crop production. The main research conclusion showed that the furrow irrigation is inefficiently operated in the fresh market tomato production, with excessive water loss affecting the watershed water quality with physical and chemical contaminants
Doutorado
Agua e Solo
Doutor em Engenharia Agrícola

Automated short furrow irrigation (ASFI) is a prototype irrigation system that has the potential to be robust and relatively low-cost, with highly effective and efficient water use. ASFI has low energy requirements because the pressure at the field edge is relatively low, typically 70 kPa (or 7 m) as compared with approximately 150 kPa for drip and 400 kPa for dragline systems. However, at project onset, the only type of ASFI system tested was Microfurrow which was, among other problems, not robust. The aim of this project was, therefore, to develop, implement and evaluate a suitable ASFI system and to compare the system to a reference sub-surface drip (SSD) irrigation system with sugarcane as the test crop. This process resulted in the development of a boot and piston valve, which was used to automatically control the flow between specific plots. The valve was then implemented, as per design, in the ASFI system at a trial at the University of KwaZulu-Natal’s Ukulinga research farm. Irrigation events were scheduled according to SAsched with the aim of applying equivalent amounts of water to both the ASF and SSD treatments. The testing and evaluation included irrigation uniformity tests and the crop yields. Evaluation of selected furrows in the ASFI treatment showed a low quarter distribution uniformity (DUlq) range between 72 % and 80 %. This is considerably better than approximately 60 % for conventional furrow irrigation. However, the DU for ASFI could be improved to above 90 % if the slope was reduced from 1:40 to approximately 1:250. Both the harvested tons per hectare and sucrose content results were evaluated using a one-way statistical analysis with differences between the results deemed to be insignificant. Therefore, the ASFI performance in terms of harvest data for the Ukulinga trial could be described as “similar to” SSD irrigation. A 10 ha sample ASFI system was designed and compared in economic terms with a respective SSD system. Although further piping options can be explored in order to reduce the capital costs of the ASFI system even further, ASFI was considerably more cost-effective than the SSD system in terms of operating and fixed costs per hectare. The ASFI irrigation system, although having some initial maintenance requirements in insuring all furrows performed properly, required no other maintenance throughout the year in the Ukulinga trial. The drip system, however, required laterals to be flushed and leaks to be repaired. It is therefore believed that the ASFI system meets the required objectives of the project in that it is robust, low-cost (both operating and fixed) and able to supply water efficiently and effectively.
Thesis (M.Sc.Eng.)-University of KwaZulu-Natal, Durban, 2010.

The shallow aquifer in Northeast Malheur County, Oregon is polluted with Nitrates at concentrations exceeding federal drinking water standards. Efforts to solve the groundwater problems in this area have focused on developing farm management practices that will increase groundwater quality while maintaining agricultural production. Furrow irrigation is the dominant practice for irrigating row crops in this region. One potential way to improve water quality is to increase furrow irrigation performance on a regional scale. In this study a surface irrigation model, SRFR, was linked to a geographic information system (GIS) for the purpose of evaluating alternate furrow irrigation strategies in Malheur County, Oregon. SRFR is a physically based model that simulates water flow and distribution in irrigated furrows. The model accepts the management parameters that influence the outcome of an irrigation and in return provides measures of water application efficiency, amount of deep percolation, amount of surface run-off, and other performance indicators. The GIS, constructed using ARC/INFO software, contains the spatial data required to run SRFR on individual fields in the region. The data for the GIS were acquired using many different sources and techniques in order to meet the input resolution required by the irrigation model. The primary goal of this research was to develop a tool for evaluating irrigation practices on a regional scale, accounting for the diversity of physical circumstances and management practices that occur within a complex of several hundred farms. The particular application of this tool was for control of nitrate pollution of groundwater in the vicinity of Ontario, Oregon. The integrated system was used to estimate a base condition irrigation that is representative of current irrigation practices. The system was then used to assess irrigation performance using three alternative practices: 1) separate management of wheel and nonwheel compacted furrows; 2) use of an automated control system to vary application set times; and 3) cutback irrigation. Although this represents only a limited assessment of the alternatives that might be considered for the study area, preliminary results suggest that under certain field conditions irrigation efficiency can potentially improve more then 20% over the base condition using alternate strategies. The system demonstrated tremendous potential for identifying trends and variability in system performance in the region.
Graduation date: 1997

碩士
國立屏東科技大學
土木工程系所
102
Rice is one of the main crops cultivated in Taiwan, accounting for the majority cultivate area. The planted rice will increase water consumption following growing process. If the rice planting process can effectively reduce the amount of water consumption that can effectively improve the efficiency of agricultural water utilization. In this study, a sand box and a 3 m #westeur024# 5 m lysimeter, located in Irrigation Promotion Center, Taiwan Chia-Nan Irrigation Association, were tested for water saving efficiency of rice consumption. In field two irrigation methods, furrow irrigation and flooding irrigation, were compared the water saving efficiency as well as the assessment of rice production under the same water storage condition. The results shown that in sand box test water started to supply the furrow irrigation mode was able to reduce 30% water consumption when the water depth of midpoint was reduced to 1 cm. In the field lysimeter test, furrow irrigation was 30% water consumption less than flooding irrigation before rice heading period. During the rice heading period, although rice growth need large amount of water the furrow irrigation was 10% less than flooding irrigation. The rice root assessment shown the development of root was more gigantic root for furrow irrigation than flooding irrigation. Because the furrow irrigation was kept water inside the ditch the soil outside of ditch were leaked that conducive to the development of air exchange with the root. The longest rice root was 20 cm for flooding irrigation however it was up to 25 cm for furrow irrigation. For furrow irrigation the average rice production was 2.86 g per plant in the wet weight for furrow irrigation more than flooding irrigation.

Furrow irrigation is the dominant practice for irrigating row crops in the western Treasure Valley region near Ontario, Oregon. Though improvements have been made in management practices over the years, excessive runoff and deep percolation are still important problems contributing to surface water and groundwater degradation. Field observations were made during two growing seasons to establish a data base from which the hydraulic surface irrigation model, SRFR (SRFR, a computer program for simulating flow in surface irrigation, developed at the U.S. Water Conservation Laboratory in Phoenix, Arizona (Strelkoff, 1991)), could be calibrated. SRFR is a numerical model, based on the principles of open channel hydraulics coupled with an empirical relationship characterizing furrow intake. SRFR is an analytical tool, with which the user supplies the physical parameters (such as furrow shape and furrow intake) and also the management variables (inflow rate and duration of inflow), and a simulation is conducted based on these conditions. Therefore, this model is a tool which provides insight into furrow irrigation processes. More specifically, SRFR can help answer such questions as which factors at the time of the irrigation are most important in determining irrigation performance. Once calibrated for a given set of conditions, various management strategies may be evaluated as to their relative effectiveness. These strategies may include, but are not limited to, cut-back irrigation, surge irrigation, alternating furrow irrigation, and laser-leveling of the field. A broad data-base is necessary for model calibration and to develop an understanding of it's limitations. Measurements of furrow intake, stream advance times, inflow and outflow, hydraulic roughness and furrow shape were obtained from several sites and irrigation events. These sites represent several crops, field lengths, field slopes, and soil textures. Using these data, a model calibration procedure was developed which matched irrigation inflow and outflow volumes and stream advance times for a given irrigation event. The calibration procedure is used to help identify those model input parameters that best describe a given irrigation event. This thesis is to provide a broad understanding of furrow irrigation systems in northeast Malheur County, recommended hydraulic parameters for use with SRFR, and the practical limitations of such hydraulic irrigation models. Irrigation performance is largely determined by the intake characteristics of the soil at the time of irrigation. Field conditions vary greatly depending on the crop, soil moisture, number of irrigations, tractor traffic, field slope, furrow shape and field history. The grower has control over only two variables which determine irrigation performance: inflow rate and duration. A difference in intake and irrigation performance was found to exist between non-wheel and wheel traffic furrows. These differences became less noticeable late in the season. Straw mulching greatly increases the furrow hydraulic roughness and therefore increases stream wetted perimeter and advance time. Vegetative interference from crops such as potato and sugar beets increase furrow hydraulic roughness late in the season. Initially, furrow shape depends on the crop and which cultivating implement is used. Furrow shape may evolve during the growing season depending on field slope, flow velocities, crop stand and the presence of crop residues and straw mulch.
Graduation date: 1996

Nitrate contamination in ground and surface waters is of great concern to environmentalists. A two-dimensional model of water and solute movement in soils was used to test the usefulness and relative advantages of a two-dimensional model over a one dimensional model for analysis of deep percolation and nitrate leaching in furrow irrigation. The predictive ability of the model was evaluated using data collected in a series of preliminary field studies. Two methods were used to calibrate the model. First, the cumulative infiltration simulated by the model was compared with an infiltration curve derived from field data. Secondly, soil water potential data were used to compare the observed movement of a wetted front in the soil profile. The calibration results closely followed the two dimensional flow pattern in furrow irrigation. The model was used both in a one-dimensional mode and a two-dimensional mode. Comparison of one-dimensional and two-dimensional models was accomplished using the two-dimensional model, with uniform infiltration across the surface boundary to represent the one-dimensional case, and with infiltration only across the furrow surface for the two-dimensional case. Evaluation of water and nitrate leaching was observed for alternate furrow irrigation as well as every-furrow irrigation with three different furrow spacings; 76, 86, and 102 cm. These results showed that the one-dimensional model always under estimates the leaching amount in comparison to the two-dimensional model. In some cases the one-dimensional model predicted no leaching of water and nitrate below the root zone though leaching was predicted by the two-dimensional model. Evaluation of alternate and every furrow irrigation with different furrow spacing indicated that the leaching amount increased rapidly with the increase of furrow spacing. Under furrow irrigation, attempts to irrigate the soil profile to a level less than, but close to, field capacity will result in leaching. Therefore different irrigation management is needed to minimize leaching. Additionally, the model suggests that the sealing layer which forms in the bottom of the furrow drastically reduced the infiltration rate because of the very low saturated hydraulic conductivity in that area. Sealing layer had a significant effect on the performance of SWMS_2D model, and made the model unusable where high input volume were required.
Graduation date: 1995

Traditional irrigation was practiced in Ethiopia since time immemorial. Despite this, water productivity in the sector remained low. A survey on the Godino irrigation scheme revealed that farmers used the same amount of water and intervals, regardless of crop species and growth stage. In an effort to improve the water productivity, two traditional irrigation scheduling methods were compared with two scientific methods, using furrow irrigation. The growth performance and tuber yield of potato (cv. Awash) revealed that irrigation scheduling using a neutron probe significantly outperformed the traditional methods, followed by the SWB model Irrigation Calendar. Since the NP method involves high initial cost and skills, the use of the SWB Calendar is suggested as replacement for the traditional methods. SWB is a generic crop growth model that requires parameters specific to each crop, to be determined experimentally before it could be used for irrigation scheduling. It also accurately describes deficit irrigation strategies where water supply is limited. Field trials to evaluate four potato cultivars for growth performance and assimilate partitioning, and onions' critical growth stages to water stress were conducted. Crop-specific parameters were also generated. Potato and onion crops are widely grown at the Godino scheme where water scarcity is a major constraint. These crop-specific parameters were used to calibrate and evaluate SWB model simulations. Results revealed that SWB model simulations for Top dry matter (TDM), Harvestable dry matter (HDM), Leaf area index (LAI), soil water deficit (SWD) and Fractional interception (FI) fitted well with measured data, with a high degree of statistical accuracy. The response of onions to water stress showed that bulb development (70-110 DATP) and bulb maturity (110-145) stages were most critical to water stress, which resulted in a significant reduction in onion growth and bulb yields. SWB also showed that onion yield was most sensitive to water stress during these two stages. An irrigation calendar, using the SWB model, was developed for five different schemes in Ethiopia, using long-term weather data and crop-specific parameters for potatoes and onions. The calendars revealed that water depth varied, depending on climate, crop type and growth stage.
Thesis (PhD)--University of Pretoria, 2009.
Plant Production and Soil Science
unrestricted