The implementation of the National Water Act (1998) requires significant changes in the institutional arrangements for water management and, to cater for human and environmental needs, as well as addressing historical inequities, water allocations to irrigated agriculture are likely to be affected. As a result, farmers are facing increasing pressure to use water more effectively, to justify existing water requirements and to budget and plan with growing uncertainty regarding water availability. Therefore, a tool to manage and assess catchment water supply and demand interactions and the associated impacts on the profitability of irrigated sugarcane would be of great value. Although there have been several independent model developments in the fields of water management and sugarcane growth, none provide the required management information in an integrated manner. However, these models provide the foundation for the development of the required modelling tool. An irrigation model for sugarcane, ACRUCane, was developed and incorporated into the ACRU2000 modelling system. The water budget simulated by ACRUCane is linked to a surrounding catchment, the hydrology of which is simulated by the ACRU model. In doing so, a tool has been developed that has the capacity to: • model the soil water balance at a field scale for irrigated areas and at a catchment scale for non-irrigated areas, • link an accurate estimation of crop water requirement for an irrigated area with the availability ofwater at a catchment scale, • explicitly account for the impact of the performance of different irrigation systems on the hydrology and, ultimately, on the sugarcane yield of an irrigated area, • assess the impact of different supply constraints on sugarcane yield, and • estimate both sugarcane and sucrose yield. Extensive verification of the model has been undertaken using data from an irrigation trial at La Mercy, South Africa and two separate trials conducted in the Lowveld of Zimbabwe, with the primary objective of the verification studies being to assess the model's ability to account for different scheduling strategies on sugarcane and sucrose yield. The results obtained show that the model accurately captured the relative differences in yield associated with different irrigation treatments and can thus be used evaluate the impact of different scheduling strategies. A case study was conducted where the feasibility of several hypothetical irrigation scenarios were compared. Different scenarios were created by varying application uniformity, scheduling strategies and system type. This case study illustrated how ACRUCane can be used to provide reliable decision support information to irrigators. / Thesis (M.Sc.Eng.)-University of KwaZulu-Natal, Durban, 2005.

Made available in DSpace on 2014-06-11T19:26:47Z (GMT). No. of bitstreams: 0 Previous issue date: 2001-02-01Bitstream added on 2014-06-13T19:34:35Z : No. of bitstreams: 1 dalri_ab_me_botfca.pdf: 2249545 bytes, checksum: 36a8655d0c1fceb1272c4dca5c706422 (MD5) / Este trabalho teve como o objetivo, verificar o efeito da freqüência da irrigação subsuperficial por gotejamento no desenvolvimento inicial da cana-de-açúcar. Os tubos gotejadores foram instalados sob a linha da cultura, a uma profundidade de 0,3 m. A cana-de-açúcar foi plantada no dia 03/03/2000 e a partir de 01/04/2000 iniciaram os tratamentos nas parcelas irrigadas. O delineamento experimental foi inteiramente casualizado, com quatro tratamentos, e quatro repetições, definidos por regimes de freqüência da irrigação. O sistema de irrigação era acionado quando a evapotranspiração da cultura atingisse 10 mm, 20 mm, e 30 mm, para os tratamentos 1, 2, e 3 respectivamente. O tratamento 4 foi definido como testemunha (não irrigado). A colheita foi realizada no dia 05/12/2000 e através da avaliação de produção de massa fresca, diâmetro e comprimento do colmo, e produção de massa seca, observou-se que não houve diferença estatística entre os diferentes regimes de freqüência de irrigação. Todavia, quando comparado com a testemunha, as irrigações proporcionaram um aumento médio maior que 45 % na produção de massa fresca e seca final dos colmos. / The aim of this study was to verify subsurface drip irrigation effects on sugarcane initial growth. Drip lines were installed under crop lines at 0,3 m depth. Sugarcane was planted in 03/03/2000, and the drip irrigation treatments began on 04/01/2000. The experimental design was entirely randomized, with four treatments and four replications, related to irrigation frequency. Irrigation system was turned on when crop evapotranspiration reached 10, 20 and 30 mm for the treatments 1, 2 e 3, respectively. Treatment 4 was the control (without irrigation). Harvest was carried out on 12/05/2000, and fresh and dry weight, stem diameter and length were evaluated; it was observed no statistical differences among irrigation frequencies, although irrigation increased fresh and dried yield over 45% when compared to the control treatment.

Over-irrigation and poor internal drainage of soils in the Indus basin of Pakistan have resulted in waterlogging and salinity problems, severely affecting agriculture. These problems may be solved by subsurface drainage or more efficient irrigation water management. Since drainage system installation is relatively expensive Pakistan, efficient irrigation management practices e.g., irrigation scheduling and on-farm water management are cheaper alternatives. / A soil water simulation model, SWAP93, was used to evaluate the effects of water stress on crop yield, water use efficiency (WUE) and crop water use in sugarcane [Saccharum officinarum L.]. This information was used to determine water management practices, which can reduce salinity and waterlogging / Drainage fluxes and evapotranspiration simulated by the model were compared with those measured in drainage lysimeters (water tables controlled at 1.5 m and 2.25 m from the soil surface) for 1989 and 1990. Drainage fluxes were overestimated, and evapotranspiration underestimated. The model's original grass-based evapotranspiration (ET) was changed to an alfalfa-based one, resulting in a better estimation of drainage fluxes and ET. / The effects of soil water balance, simulated by the SWAP93, on the crop yield, WUE and crop water use were assessed using twelve irrigation treatments consisting of four irrigation amounts (1800, 1650, 1200 and 900 mm) factorially combined with three irrigation intervals (7, 10 and 15 days) for seven years of climatic data. / Crop yields increased linearly with irrigation of 1200 mm during the growing season, Crop yield, ET and WUE were not significantly different for irrigation amounts ranging from 1200 to 1800 mm. When the total applied water was above 1400 mm, the crop yield showed a plateau. This maximum yield was reached because irrigation water was remained in the soil profile or percolated into deeper layers at high levels of irrigation application. / For a 7-day irrigation interval, the 1200 mm treatment showed water deficits during the middle of the growing season, whereas for 10- or 15-day irrigation intervals, water deficits were negligible. / A 3rd degree polynomial relationship between cumulative irrigation amount and drainage fluxes was developed, allowing a daily estimation of irrigation amount for a given percolation or capillary rise. This relationship can be used to optimize irrigation amounts, and evaluate their impacts on percolation losses. / From the results of this simulation study, it was predicted that the 1200 mm---15 irrigation application treatment (15 day interval) was best for irrigation scheduling to reduce salinity and waterlogging.

Orientador: Raimundo Leite Cruz / Banca: Antonio Evaldo Klar / Banca: Ailto Antonio Casagrande / Resumo: Este trabalho teve como o objetivo, verificar o efeito da freqüência da irrigação subsuperficial por gotejamento no desenvolvimento inicial da cana-de-açúcar. Os tubos gotejadores foram instalados sob a linha da cultura, a uma profundidade de 0,3 m. A cana-de-açúcar foi plantada no dia 03/03/2000 e a partir de 01/04/2000 iniciaram os tratamentos nas parcelas irrigadas. O delineamento experimental foi inteiramente casualizado, com quatro tratamentos, e quatro repetições, definidos por regimes de freqüência da irrigação. O sistema de irrigação era acionado quando a evapotranspiração da cultura atingisse 10 mm, 20 mm, e 30 mm, para os tratamentos 1, 2, e 3 respectivamente. O tratamento 4 foi definido como testemunha (não irrigado). A colheita foi realizada no dia 05/12/2000 e através da avaliação de produção de massa fresca, diâmetro e comprimento do colmo, e produção de massa seca, observou-se que não houve diferença estatística entre os diferentes regimes de freqüência de irrigação. Todavia, quando comparado com a testemunha, as irrigações proporcionaram um aumento médio maior que 45 % na produção de massa fresca e seca final dos colmos. / Abstract: The aim of this study was to verify subsurface drip irrigation effects on sugarcane initial growth. Drip lines were installed under crop lines at 0,3 m depth. Sugarcane was planted in 03/03/2000, and the drip irrigation treatments began on 04/01/2000. The experimental design was entirely randomized, with four treatments and four replications, related to irrigation frequency. Irrigation system was turned on when crop evapotranspiration reached 10, 20 and 30 mm for the treatments 1, 2 e 3, respectively. Treatment 4 was the control (without irrigation). Harvest was carried out on 12/05/2000, and fresh and dry weight, stem diameter and length were evaluated; it was observed no statistical differences among irrigation frequencies, although irrigation increased fresh and dried yield over 45% when compared to the control treatment. / Mestre

No description available.

Typescript (photocopy) / Thesis (Ph. D.)--University of Hawaii at Manoa, 1980. / Bibliography: leaves 219-232. / Microfiche. / xxi, 232 leaves, bound ill. 28 cm

The purpose of this study was to develop a framework to assess irrigation design and operating strategies. This objective was achieved successfully and the framework was applied to formulate guidelines to increase farm profitability whilst using scarce resources, such as water and electricity, effectively. The study was targeted at sugarcane irrigated with semi-permanent irrigation systems. “ZIMsched 2.0”, a water balance and crop yield prediction model and the “Irriecon V2” economic assessment model were available at the start of the study. The missing link, however, was a relatively cost effective and efficient method to design and cost irrigation hardware alternatives. Irrigation hardware impacts on both the agronomic and economic performance of systems, for example, through different peak design capacities and associated operating limitations. Thus, a novel, spreadsheet-based irrigation design tool, with an automated costing component, was developed to complete the framework. The framework was used to investigate the costs and benefits of potential design and operating solutions to a selection of irrigation issues, including: over-irrigation on shallow soils, the opportunity to shift electricity use out of expensive peak periods and, the opportunity to demonstrate the benefits of deficit irrigation strategies. For shallow soils, the increase in system hardware costs, needed to better match water application to soils, increased margins due to more effective water use. Innovative deficit designs and operating strategies allowed for reductions in water and electricity costs. The reduced costs, however, did not always offset yield penalties and revenue loss resulting from water stress. The financial benefits of deficit irrigation strategies were shown when water savings were used to convert dry land cane into irrigated cane. This highlighted the differences between the direct and opportunity costs of water. Finally, a field work component, relating to the precise monitoring of irrigation strategies and corresponding crop responses was included in this study. Systems which enabled soil water potential and stalk extension to be monitored remotely via the internet were considered useful for the successful implementation of an optimum irrigation strategy. The easily accessible data allows for effective decision making and more importantly, reassures famers of the current state of their crop. / Thesis (M.Sc.)-University of KwaZulu-Natal, Durban, 2009.

Typescript. / Thesis (Ph. D.)--University of Hawaii at Manoa, 1979. / Bibliography: leaves 145-157. / Microfiche. / xii, 157 leaves ill. 29 cm

Made available in DSpace on 2014-06-11T19:28:36Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-02-27Bitstream added on 2014-06-13T18:34:59Z : No. of bitstreams: 1 pannuti_ler_me_botfca.pdf: 622900 bytes, checksum: bda95b3ae7dc13a1a939e2044d8b34f9 (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O Brasil se destaca como o maior produtor mundial de cana-de-açúcar (Saccharum sp.). A produtividade desta cultura está intimamente relacionada à disponibilidade de água e nitrogênio durante seu desenvolvimento e também à incidência de insetos-praga. Dentre as espécies mais nocivas à cana-de-açúcar no Estado de São Paulo, destacam-se a broca da cana-de-açúcar, Diatraea saccharalis Fabr.,1794 (Lepidoptera: Crambidae) e as cigarrinhas do gênero Mahanarva, as quais têm comprometido seriamente as produtividades sob cultivo sem despalha a fogo (cana crua). Neste contexto, o presente trabalho teve como objetivos: avaliar o efeito da fertirrigação nitrogenada por meio de gotejamento subsuperficial, sobre a incidência e os danos ocasionados por D. saccharalis e M. fimbriolata em cana-de-açúcar (SP80-3280). Foram realizados dois experimentos simultâneos na Unidade de Pesquisa e Desenvolvimento da APTA de Jaú-SP. O primeiro foi composto por quatro tratamentos e quatro repetições em delineamento de blocos casualizados (DBC). Os tratamentos foram constituídos de duas doses de N-fertilizante e dois manejos de disponibilidade hídrica: (1) 0 de N-fertilizante com irrigação; (2) 150 kg ha-1 de N-fertilizante com irrigação; (3) 0 de N-fertilizante no manejo de sequeiro e (4) 150 kg ha-1 de N-fertilizante no manejo de sequeiro. No mesmo período, foi conduzido outro ensaio, também em delineamento de blocos casualizados (DBC), constituído por cinco doses de N-fertilizante, em sistema de irrigação por gotejamento: (1) 0 de N-fertilizante (controle); (2) 50 kg ha-1 de N-fertilizante; (3) 100 kg ha-1 de N-fertilizante; (4) 150 kg ha-1 de N-fertilizante e (5) 200 kg ha-1 de N-fertilizante. Periodicamente, foram realizadas avaliações do nível de infestação da broca da cana-de-açúcar e da cigarrinha. Os parâmetros... / Brazil stands out as the world's largest producer of sugarcane (Saccharum sp.). The productivity of this culture is closely related to the availability of water and nitrogen during its development and also the incidence of pest insects. Among the species most harmful to the sugar cane in the São Paulo state, stand out the sugarcane borer, Diatraea saccharalis Fabr.,1794 (Lepidoptera: Crambidae) and the sharpshooter of the genus Mahanarva, which has seriously endangered the yields under cultivation without the use of fire (cane). In this context, the present study aimed to evaluate the effect of the fertirrigation fertilization by means of subsurface drip, on the incidence and the damage caused by D. saccharalis and M. fimbriolata in sugarcane (SP80-3280). Two experiments were carried out simultaneously in Research and Development Unit of APTA to Jau-SP. The first was composed of four treatments and four replications in a randomized design (RBD). The treatments were composed of two doses of N-fertilizer and two managements of availability of water: (1) 0 N fertilizer with irrigation; (2) 150 kg ha-1 of N-fertilizer with irrigation; (3) 0 of N-fertilizer in the management of rainfed and (4) 150 kg ha-1 of N-fertilizer in the management of rainfed. In the same period, was conducted another test, also in a randomized complete block design (RBD), consisting of five doses of N-fertilizer, in irrigation system drip irrigation: (1) 0 N-fertilizer (control); (2) 50 kg ha-1 of N-fertilizer; (3) 100 kg ha-1 of N-fertilizer; (4) 150 kg ha-1 of N-fertilizer and (5) 200 kg ha-1 of N-fertilizer. Periodically, assessments were made in the level of infestation of the sugarcane borer and the sharpshooter. The parameters evaluated for sugarcane borer were: the number of holes, number of internodes with red rot and... (Complete abstract click electronic access below)

Orientador: Edson Luiz Lopes Baldin / Coorientador: Glauber José de Castro Gava / Banca: Juliana Cristina Sodário Cruz / Banca: Rogério Soratto / Resumo: O Brasil se destaca como o maior produtor mundial de cana-de-açúcar (Saccharum sp.). A produtividade desta cultura está intimamente relacionada à disponibilidade de água e nitrogênio durante seu desenvolvimento e também à incidência de insetos-praga. Dentre as espécies mais nocivas à cana-de-açúcar no Estado de São Paulo, destacam-se a broca da cana-de-açúcar, Diatraea saccharalis Fabr.,1794 (Lepidoptera: Crambidae) e as cigarrinhas do gênero Mahanarva, as quais têm comprometido seriamente as produtividades sob cultivo sem despalha a fogo (cana crua). Neste contexto, o presente trabalho teve como objetivos: avaliar o efeito da fertirrigação nitrogenada por meio de gotejamento subsuperficial, sobre a incidência e os danos ocasionados por D. saccharalis e M. fimbriolata em cana-de-açúcar (SP80-3280). Foram realizados dois experimentos simultâneos na Unidade de Pesquisa e Desenvolvimento da APTA de Jaú-SP. O primeiro foi composto por quatro tratamentos e quatro repetições em delineamento de blocos casualizados (DBC). Os tratamentos foram constituídos de duas doses de N-fertilizante e dois manejos de disponibilidade hídrica: (1) 0 de N-fertilizante com irrigação; (2) 150 kg ha-1 de N-fertilizante com irrigação; (3) 0 de N-fertilizante no manejo de sequeiro e (4) 150 kg ha-1 de N-fertilizante no manejo de sequeiro. No mesmo período, foi conduzido outro ensaio, também em delineamento de blocos casualizados (DBC), constituído por cinco doses de N-fertilizante, em sistema de irrigação por gotejamento: (1) 0 de N-fertilizante (controle); (2) 50 kg ha-1 de N-fertilizante; (3) 100 kg ha-1 de N-fertilizante; (4) 150 kg ha-1 de N-fertilizante e (5) 200 kg ha-1 de N-fertilizante. Periodicamente, foram realizadas avaliações do nível de infestação da broca da cana-de-açúcar e da cigarrinha. Os parâmetros... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Brazil stands out as the world's largest producer of sugarcane (Saccharum sp.). The productivity of this culture is closely related to the availability of water and nitrogen during its development and also the incidence of pest insects. Among the species most harmful to the sugar cane in the São Paulo state, stand out the sugarcane borer, Diatraea saccharalis Fabr.,1794 (Lepidoptera: Crambidae) and the sharpshooter of the genus Mahanarva, which has seriously endangered the yields under cultivation without the use of fire (cane). In this context, the present study aimed to evaluate the effect of the fertirrigation fertilization by means of subsurface drip, on the incidence and the damage caused by D. saccharalis and M. fimbriolata in sugarcane (SP80-3280). Two experiments were carried out simultaneously in Research and Development Unit of APTA to Jau-SP. The first was composed of four treatments and four replications in a randomized design (RBD). The treatments were composed of two doses of N-fertilizer and two managements of availability of water: (1) 0 N fertilizer with irrigation; (2) 150 kg ha-1 of N-fertilizer with irrigation; (3) 0 of N-fertilizer in the management of rainfed and (4) 150 kg ha-1 of N-fertilizer in the management of rainfed. In the same period, was conducted another test, also in a randomized complete block design (RBD), consisting of five doses of N-fertilizer, in irrigation system drip irrigation: (1) 0 N-fertilizer (control); (2) 50 kg ha-1 of N-fertilizer; (3) 100 kg ha-1 of N-fertilizer; (4) 150 kg ha-1 of N-fertilizer and (5) 200 kg ha-1 of N-fertilizer. Periodically, assessments were made in the level of infestation of the sugarcane borer and the sharpshooter. The parameters evaluated for sugarcane borer were: the number of holes, number of internodes with red rot and... (Complete abstract click electronic access below) / Mestre