South Africa is a water scarce country. As pressure on available water resources increases, irrigation, the largest consumer of water, has to find ways of improving water use efficiency. Benchmarking in the irrigation sector has been identified as a suitable technique to implement this improvement. Benchmarking can be broadly defined as the identification and application of organisation specific best practices with the goal of improving competitiveness, performance and efficiency. A South African sugarcane irrigation scheme was identified to investigate a proposed benchmarking methodology. The scheme was unique in that electromagnetic flow meters were utilised and monitored on a daily basis. This facilitated an in depth study into irrigation water use at the scheme. The project focused on three different objectives. The first objective was to determine the losses, and consequently the efficiency, with which the irrigation scheme was able to deliver irrigation water from the water source to the farm boundary during the years 2004 and 2005. This was achieved by completing the water balance for the scheme with specified geographic and temporal boundaries. Results indicated that the scheme was very efficient with a delivery efficiency of 83.4 and 94.0 % for 2004 and 2005 respectively. These efficiencies were above the accepted South African Department of Water Affairs and Forestry (DWAF) standard of 80 %. The temporal distribution of the delivery efficiency was also investigated to identify periods within each year when inefficiencies occurred, and to better understand the nature of potential losses. It was concluded that the investigations into the temporal distributions be utilised together with the water balance approach in future studies into the performance of irrigation water delivery infrastructure at other South African irrigation schemes. The second objective was to calculate a set of internationally applied external irrigation benchmarking indicators. External indicators from the International Water Management Institute (1WMI), the International Program for Training and Research in Irrigation and Drainage (IPTRID) and the Irrigation Training and Research Center (ITRC) were reviewed for application in a South African context. The external indicator analysis highlighted that at a scheme level, insufficient irrigation was occurring to effectively meet the irrigation demand. It was also found that the scheme infrastructure was not the limiting cause of this observation. The external indicator results highlighted the need for additional schemes for comparison purposes. The results from this component of the study also emphasized the importance of stakeholder confidentiality concerns when attempting to implement a benchmarking initiative. The third objective was to rank individual farm performance of all the farms in the scheme, in terms of total farm sugarcane yield and seasonal irrigation water use. Farm yield and irrigated area were obtained to investigate the relationships between yield and irrigation water application. There were substantial variations in total farm yield and water use for both the 2004 and 2005 seasons, indicating much potential for improvement by many farmers relative to each other. The individual seasonal farm water use was also compared to a simulated irrigation demand, as determined with the SAsched irrigation systems and crop yield model. Simulation results with the SAsched model, using representative soils and climate data for the scheme, showed that the majority of farms were under irrigating relative to the simulated demands, especially in the late spring/early summer period. From on-farm irrigation system evaluations that were performed, it was found that irrigation system capacity constraints were not limiting irrigation applications in the majority of farms. Further research in the form of selected soil water monitoring is required to investigate these observations further. / Thesis (M.Sc.)-University of KwaZulu-Natal, 2007.

The goal of irrigation is to supply sufficient water for crop growth to all areas within a field. Therefore, the uniformity of application of irrigation water is of great importance. The objectives of this study were to quantify the performance of irrigation systems under field conditions using standard evaluation techniques and to investigate the use of spatial statistics to characterise the spatial variability of application. The main objective was to develop techniques to estimate gross irrigation water requirement that incorporates the uniformity of application. Different practitioners have given different definitions to the criteria used to evaluate the performance of an irrigation system. A literature review was conducted to determine the current definitions used and the factors that affect these performance criteria. The theory and application of spatial statistics was investigated in order to charaterise spatial distribution of irrigation water. The spatial distribution of irrigation water under centre pivots was determined using field measurements. A number of centre pivot, sprinkler, floppy, drip and micro-irrigation systems were evaluated using standard techniques. The results from the evaluation of spatial data show that this approach is useful to determine a map of the distribution of applied irrigation water. Due to the smoothing characteristic of the spatial statistical method employed, the maps have a uniformity that is greater than in reality. The results from the standard evaluation techniques show that quick and representative results for the performance of an irrigation system can be obtained. The distribution uniformity has an affect on the efficiency of a system and should therefore be included in the calculation of the gross irrigation water requirement. The methods for these calculations are discussed. Further research needs to be conducted to determine actual distribution uniformities and application efficiencies for irrigation systems under various field conditions. This will provide useful standards to include in the calculation of gross irrigation water requirements. / Thesis (M.Sc.)-University of Natal, Durban, 2001.

Typescript. / Thesis (Ph. D.)--University of Hawaii at Manoa, 1989. / Includes bibliographical references (114-120) / Microfiche. / xi, 120 leaves, bound ill. 29 cm

Thesis (Ph.D.)--University of Melbourne, Agriculture and Food Systems,Faculty of Land and Food Resources, 2006. / Typescript. Includes bibliographical references.

Thesis (Ph.D.). / Written for the Dept. of Bioresource Engineering. Title from title page of PDF (viewed 2008/02/12). Includes bibliographical references.

Thesis (MScAgric (Soil Science))--University of Stellenbosch, 2008. / In order to produce table grapes of export quality economically, irrigation must be practised conservatively without adversely affecting the crop. To use water as conservatively as possible effective irrigation scheduling practices must be applied. The highest water use efficiency (WUE) is only possible if irrigation scheduling practices lower the amount of water applied, while at the same time they increase the yield. The first aim of this project is to investigate whether current irrigation practices make efficient use of water by comparing irrigation requirements determined using theoretical models with actual irrigation applied for two seasons (2005/6 and 2006/7). Secondly, the effect of cumulative irrigation on the chemical status of soil in 16 blocks was investigated to establish whether nutrient leaching as a result of differential water use may have had an influence on yield. Six blocks (three dripper and three microsprinkler blocks) were selected and irrigation requirements were determined using evaporation pan calculations, SAPWAT and Vinet and compared with actual irrigation applications. Furthermore, a yield-irrigation index (kg/m3) and an income-irrigation index (R/m3) were determined for each of the six blocks and compared. To investigate the effect of cumulative water use on the chemical status of the soils of 16 blocks, soil samples were taken and analysed for pH (1M KCl), EC (1:5); soluble cations and anions (Ca, Mg, Na, K, SO4, NO3, and Cl), ammonium acetate extractable cations (Ca, Mg, Na and K) and micro elements (Zn, Fe, Mn, Cu and B). The irrigation requirements predicted by the different irrigation scheduling methods are variable. For Vinet, the irrigation requirement determined for microsprinkler irrigation is much higher than that determined using the evaporation pan or SAPWAT approaches. Comparison of the irrigation applied to each of these blocks does not clarify whether any irrigation scheduling takes place. Results showed a relationship between the yield-irrigation index and income-irrigation index. It has not however been verified whether this relationship is statistically significant.

Thesis (MBA)--Stellenbosch University, 2012. / This research study analyses the market potential for the Floppy Sprinkler irrigation system in the global market. It explores the global irrigation market and its environment to identify the driving forces that influence the industry as well as the potential that Floppy Sprinkler could unleash as a competitor. The researcher assesses the industry value chain to determine the fit and alliance opportunities for Floppy Sprinkler in the value chain. The study further analyses the competitive pressures influencing the competitive environment. Applied research is used in this study to gain a comprehensive understanding of the market. Acknowledged diagnostic models in the field of strategic management were used to guide the study. These included the PESTLE analysis to evaluate the macro-environment of the agriculture sector; the value chain analysis to assess the agricultural industry value chain; Porter’s Five Forces Model to analyse the competitive pressures for Floppy Sprinkler; and the SWOT analysis to identify the strengths, weaknesses, opportunities and threats. The relevant data were collected through both primary and secondary sources. Two questionnaires were designed, the first to industry specialists in the agriculture sector with the purpose to gain insight of the irrigation and agriculture environment; and the second to Floppy Sprinkler irrigation system users, with the purpose to obtain a rating, opinion and relevance of the product in the market. The research disclosed that forces within the macro environment influence the industry significantly. These specifically revolved around climate change, water scarcity, land availability, soil degradation, population growth and changing lifestyles. The value chain analysis revealed that opportunities exist in the agriculture industry to create horizontal and vertical alliances to strengthen Floppy Sprinkler’s position in the market. Competitive pressures in the market include direct competitors of Floppy Sprinkler, as well as the bargaining power of suppliers and buyers. Threat of new entrants and substitute products are not perceived to be immediate competitive pressures for Floppy Sprinkler owing to its cutting-edge technology, which offers a distinctive competitive advantage. Finally, opportunities were identified, which served as recommendations for Floppy Sprinkler in developing its strategy.

The decline of groundwater levels in Final County, Arizona has not only resulted in land subsidence, but has entailed higher pumping costs for irrigation water. The Pinal Active Management Area (PAMA) is thus one of four critical groundwater overdraft areas in which water conservation is to be enforced by mandate of the Arizona Groundwater Management Act. The Groundwater Management Act as it relates to the PAMA is evaluated with respect to an accepted theoretical groundwater management model in order to determine its potential effectiveness in achieving basin-wide water conservation. The indications are that implementation problems may greatly reduce the effectiveness of the Act. The potential for farm-level water conservation is evaluated by performing a detailed benefit-cost analysis of four alternative on-farm water conservation measures. These include laser leveling, which improves the water application efficiency of traditional furrow irrigation systems from 60 to 85 percent, the installation of center pivot or drip irrigation systems, with potential water application efficiencies of 75 and 90 percent respectively, and the introduction of lettuce, a high-value and less water-intensive crop, into the traditional crop mix. The social and private profitability measures obtained from the analysis indicate that only cotton and lettuce show a profit in the long run with respect to all the irrigation systems, and these profits are highest when farms are laser leveled. The remaining traditional crops, namely alfalfa, wheat, barley, sorghum and safflower, all indicate losses. The magnitude of these losses is least in laser leveled farms. When crops are combined in a farming enterprise so as to simulate more realistic conditions, laser leveling yields the highest net returns to water in the long run. These results lead to the conclusion that the effectiveness of the Groundwater Management Act can be considerably enhanced by providing incentives that encourage farmers to invest in laser leveling.

Typescript (photocopy). / Digitized by Kansas Correctional Industries

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)