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Fenotipagem para estudos de estudos de tolerância à deficiência hídrica em eucalipto

Mendes, Hélio Sandoval Junqueira
Fonte: Universidade Estadual Paulista (UNESP) Publicador: Universidade Estadual Paulista (UNESP)
Tipo: Tese de Doutorado Formato: vii, 67 p. : il.
POR
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36.42%
Pós-graduação em Agronomia (Genética e Melhoramento de Plantas) - FCAV; The eucalyptus culture has great importance for the Brazilian forestry sector, being an excellent timber option for many purposes. Over recent years, the eucalyptus cultivation has expanded to regions with high levels of water deficit, imposing a new challenge for breeders and foresters that is recommendation of drought resistant genotypes. Thus, this work aim to evaluate the imposition of different ways of water stress on eucalypt, provided by types of pots and irrigation schemes combination, in order to advance in phenotyping methods in drought tolerance studies. Therefore, changes in Eucalyptus clones seeding physiological, biochemical and growth under different water availability conditions were studied. Three experiments were conducted: the first was conducted in cylindrical recipients of PVC under two irrigation regimes (R1 - alternate day and R2 - interruption of watering until visible wilting occurred) and three hybrids (H1 and H2 - Eucalyptus urophylla x E. tereticornis and H3 - hybrid E. urophylla x E. brassiana). Were evaluated in this experiment the following aspects: a) growth: height, stem diameter, number of leaves, leaf area, dry mass of leaves of stem + branches...

Simulation of automatic control of an irrigation canal

Lozano, David; Arranja, Carina; Rijo, Manuel; Mateos, Luciano
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica Formato: 74590 bytes; application/pdf
ENG
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Improved water management and efficient investment in the modernization of irrigation schemes are essential measures in many countries to satisfy the increasing demand for water. Automatic control of the main canals is one method for increasing the efficiency and flexibility of irrigation systems. In 2005, one canal in the irrigation scheme ‘Sector BXII del Bajo Guadalquivir’ was monitored. This canal is representative of irrigation schemes in Southern Spain; it is divided into four pools and supplies an area of 5,154 ha. Ultrasonic sensors and pressure transducers were used to record the opening of gates and water levels at the upstream and downstream ends of each canal pool. Using the recorded data and the SIC (Simulation of Irrigation Canals) hydraulic model, two canal control options (local upstream control and distant downstream control) were evaluated using a Proportional-Integral control algorithm. First, the SIC model was calibrated and validated under steady-state conditions. Then the proportional and integral gains of the PI algorithm were calibrated. The controllers were tested using theoretical demand changes (constant outflow followed by a sudden demand increase or decrease) and real demand changes generated on the basis of a spatially distributed crop water balance that included a number of sources of variability (random and not random) in the determination of field irrigation timing and depth. The results obtained show that only the distant downstream controller was able...

Impact of dams and irrigation schemes in Anopheline (Diptera: Culicidae) bionomics and malaria epidemiology

Sanchez-Ribas,Jordi; Parra-Henao,Gabriel; Guimarães,Anthony Érico
Fonte: Instituto de Medicina Tropical Publicador: Instituto de Medicina Tropical
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/08/2012 EN
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Irrigation schemes and dams have posed a great concern on public health systems of several countries, mainly in the tropics. The focus of the present review is to elucidate the different ways how these human interventions may have an effect on population dynamics of anopheline mosquitoes and hence, how local malaria transmission patterns may be changed. We discuss different studies within the three main tropical and sub-tropical regions (namely Africa, Asia and the Pacific and the Americas). Factors such as pre-human impact malaria epidemiological patterns, control measures, demographic movements, human behaviour and local Anopheles bionomics would determine if the implementation of an irrigation scheme or a dam will have negative effects on human health. Some examples of successful implementation of control measures in such settings are presented. The use of Geographic Information System as a powerful tool to assist on the study and control of malaria in these scenarios is also highlighted.

Comparison Assessment of Water Use and Damage between Modern and Traditional Rice Irrigation Schemes: Case of Usangu Basin, Tanzania

Machibya, Magayane; Mdemu, Makarius
Fonte: Molecular Diversity Preservation International (MDPI) Publicador: Molecular Diversity Preservation International (MDPI)
Tipo: Artigo de Revista Científica
EN
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Water management and competition between users in water scarce river basins is a major challenge facing the human race. The inter dependence of users in such basins, necessitates a clear understanding of each user in relation to the location, the water demand, and the duration of water need. The understanding of these factors, together, is very important for the management of water resources in such basins without which, it is argued that, water is overused and wasted. As an example of this, the large modern and improved rice irrigation systems in Tanzania are believed to use water more efficient than the traditional irrigation systems. Yet, well-founded scientific analyses are a necessary part to quantify such beliefs as they can inform us whether the natural resource, in such systems, is properly utilized and managed or not. Likewise, such studies can allow us to quantify how much water is over used and thus the natural resource is unnecessarily degraded. This paper explores a study conducted in the Usangu basin, Tanzania, to investigate the gross and net needs for modern and traditional rice irrigation schemes, and the implications with regards to water resource management and damage. Problems relating to modernization of traditional smallholder irrigation systems and upstream - downstream water users are further discussed. The paper concludes from the study that modern irrigation schemes are inefficient compared to traditional irrigation schemes. Also modernization of traditional schemes in the study area have resulted into over abstraction and reduced productivity of water. Looking to the future...

Yield Impact of Irrigation Management Transfer : Story from the Philippines

Bandyopadhyay, Sushenjit; Shyamsundar, Priya; Xei, Mei
Fonte: World Bank, Washington, DC Publicador: World Bank, Washington, DC
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Irrigation management transfer is an important strategy among donors and governments to strengthen farmer control over water and irrigation infrastructure. This study seeks to understand whether irrigation management transfer is meeting the promise of its commitments. The authors use data from a survey of 68 irrigator associations and 1,020 farm households in the Philippines to estimate the impact of irrigation management transfer on irrigation association performance and on rice yields. They also estimate a stochastic frontier production function to assess contributions to technical efficiency. There are three main results. First, the presence of irrigation management transfer is associated with an increase in maintenance activities undertaken by irrigation associations. Second, by increasing local control over water delivery, the presence of irrigation management transfer is associated with a 2-6 percent increase in farm yields. Rice production in irrigation management transfer areas is greater even after controlling for various differences among rice farmers in transfer and non-transfer areas. Third...

Participation in the Irrigation Sector

Meinzen-Dick, Ruth; Reidinger, Richard; Manzardo, Andrew
Fonte: World Bank, Washington, DC Publicador: World Bank, Washington, DC
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The irrigation sector provides a rich source of experiences and lessons in user participation. Participation by farmers in system design and management helps to ensure the sustainability of the system, reduce the public expenditure burden, and improve efficiency, equity and standards of service. Mobilizing support at all levels and establishing the participatory process, however, involves costs; it also demands knowledge of the incentives facing each group of stakeholders, and of the essential elements in building effective users organizations.

The Use of Output-Based Aid in Small Scale Irrigation Schemes in Developing Countries

World Bank
Fonte: Washington, DC Publicador: Washington, DC
EN_US
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This report has been completed to explore the use of output-based aid (OBA) as a financing mechanism to support the development and operation of small-scale irrigation schemes in developing countries. The specific objectives of the report were to: evaluate the scope for OBA in financing small-scale irrigation schemes to support poor farmers in developing countries and propose project design and implementation arrangements, based on real-world examples, to support sustainable small scale irrigation schemes benefiting from OBA, either under public or private management. The aim is being to provide recommendations on the appropriate next steps for using OBA subsidies to support the implementation of projects in the irrigation sector.

The Possibility of a Rice Green Revolution in Large-scale Irrigation Schemes in Sub-Saharan Africa

Nakano, Yuko; Bamba, Ibrahim; Diagne, Aliou; Otsuka, Keijiro; Kajisa, Kei
Fonte: Banco Mundial Publicador: Banco Mundial
Tipo: Publications & Research :: Policy Research Working Paper
ENGLISH
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This paper investigates the potential of and constraints to a rice Green Revolution in Sub-Saharan Africa's large-scale irrigation schemes, using data from Uganda, Mozambique, Burkina Faso, Mali, Niger, and Senegal. The authors find that adequate irrigation, chemical fertilizer, and labor inputs are the key to high productivity. Chemical fertilizer is expensive in Uganda and Mozambique and is barely used. This is aggravated when water access is limited because of the complementarities between fertilizer and irrigation. Meanwhile, in the schemes located in four countries in West Africa's Sahel region, where water access is generally good and institutional support for chemical fertilizer exists, rice farmers achieve attractive yields. Some countries' wage rate is high and thus mechanization could be one solution for this constraint. Improvement of credit access also facilitates the purchase of expensive fertilizer or the employment of hired labor.

Methodology for Ranking Irrigation Infrastructure Investment Projects

World Bank
Fonte: Washington, DC Publicador: Washington, DC
Tipo: Economic & Sector Work :: Policy Note; Economic & Sector Work
ENGLISH; EN_US
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The Government of Uzbekistan is aware that the irrigation and drainage infrastructure constructed under the Former Soviet Union - serving some 4.3 million hectare of cultivable land for agriculture as well as many villages for drinking water - is in urgent need of repair and/or rehabilitation. Also, given multiple competing demands of investment project proposals (as many as 180) on the nation's limited, annual investment budget earmarked for this purpose, it realized the need for a national strategy aimed at modernizing the water sector including a medium-term investment plan. It has thus asked the World Bank to undertake, over a two-year period beginning in mid-2007, a study that is designed to provide solutions to the twin problems of how to approach the rehabilitation of the irrigation and drainage sub-sector and which of the many competing projects to prioritize. To overcome this problem as well as the general lack of readily available, comparable data of proposals, the technical working group used the Investment project data sheet to gather relevant information from sub-basin authorities throughout the country with the instruction to fill in the required information. Initial progress with data collection proved extremely slow and cumbersome as the habit of looking at projects in an integrated manner...

Making a Large Irrigation Scheme Work : A Case Study from Mali

World Bank
Fonte: Washington, DC Publicador: Washington, DC
Tipo: Publications & Research :: Brief; Publications & Research
ENGLISH
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Located in the heart of Mali, the Office du Niger (ON) is one of the oldest and largest irrigation schemes in Sub-Saharan Africa. The French, who began the scheme in 1932, planned on developing about 1,000,000 hectares (ha) over a period of 50 years. The scheme did not provide the expected resources for cotton and rice farming, and a major source of exploitation of farmers. Change began in the 1980's with Government/donor led reforms that resulted in dissolving the monopoly power of ON and increasing citizen participation in its management. This report provides the context and details on how the government of Mali became committed to reform of the ON, an irrigated rice scheme. The government's decision is presented as the outcome of a series of small power shifts triggered by pro-reform players. Reform advocates played a key role, and identified opportunities and applied their skills to tilt the power balance between agency and farmers to further goals of sustainability and partnership. Initial steps for reform had a significant impact...

Africa : Irrigation investment Needs in Sub-Saharan Africa

You, Liang Zhi
Fonte: Washington, DC, World Bank Publicador: Washington, DC, World Bank
Tipo: Economic & Sector Work :: Other Infrastructure Study; Economic & Sector Work
ENGLISH; EN_US
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In Sub-Saharan Africa, rainfall is highly variable and, in many places, plainly in sufficient. Although irrigation has the potential to boost agricultural yields by at least 50 percent, food production in the region is almost entirely rain-fed. The irrigated area, extending over 6 million hectares, makes up just 5 percent of the total cultivated area, compared to 37 percent in Asia and 14 percent in Latin America. Two-thirds of that area is in three countries: Madagascar, South Africa, and Sudan. The 2005 Commission for Africa report, for example, called for a doubling of the region's irrigated area by 2015. To achieve expansion on that scale, however, we must deepen our understanding of the locations that could benefit most-and of the technologies best suited to those locations. One purpose of this study of irrigation in 24 countries, undertaken as part of the Africa infrastructure country diagnostic, is to identify agricultural areas, where irrigation investments promise to yield significant returns. A related purpose is to estimate the amount and scope of investment needed to secure those returns. Water for irrigation can be collected in two ways: through large...

Emerging Public-Private Partnerships in Irrigation Development and Management

Darghouth, Salah
Fonte: World Bank, Washington, DC Publicador: World Bank, Washington, DC
Tipo: Publications & Research :: Working Paper; Publications & Research
ENGLISH; EN_US
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The objective of this paper is to identify the possible role and opportunities for the private sector to participate with governments and farmers in developing and managing irrigation and drainage (I&D) infrastructure. Over the last 50 years, irrigated agriculture has been vital to meeting fast-rising food demand and has been key to poverty reduction. In the coming years the strong demographic demand for food is expected to continue, and intensified irrigated agriculture will have to provide close to 60 percent of the extra food. However, in recent years, the pace of irrigation expansion has been slowing, there has been less improvement in productivity, and water availability for irrigation is increasingly constrained. Governments have long led the expansion of large-scale irrigation, but performance has been suboptimal, and reforms that have been introduced have proved slow to improve efficiency and water service. Faced with this challenge, the I&D sector has been wrestling with three deep-seated problems: low water use efficiency...

An Impact Evaluation of India's Second and Third Andhra Pradesh Irrigation Projects : A Case of Poverty Reduction with Low Economic Returns

Independent Evaluation Group
Fonte: Washington, DC : World Bank Publicador: Washington, DC : World Bank
Tipo: Publications & Research :: Publication; Publications & Research :: Publication
ENGLISH; EN_US
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56.64%
Irrigation has made a major contribution to poverty reduction in the past decades, enabling higher yields and better nutrition. Despite these achievements, large-scale irrigation schemes have usually yielded low returns and attracted negative publicity because of their adverse environmental and social impacts. As a result, the Bank has largely switched its support for irrigation away from new construction toward rehabilitation and policy reform. This evaluation supports the need for reform but shows that there are substantial benefits from further investment in infrastructure. This study analyzes these issues through an impact evaluation of one of the last "old generation" of projects in which the Bank directly supported creation of a new irrigation scheme: India's Second and Third Andhra Pradesh Irrigation Projects (AP II and AP III). Together these projects created a new command area, the Srisailem Right Branch Canal (SRBC), and rehabilitated an existing one that had been constructed with Bank assistance...

Impact of dams and irrigation schemes in Anopheline (Diptera: Culicidae) bionomics and malaria epidemiology; Impacto de hidrelétricas e campos de irrigação na bionomia dos anofelinos (Diptera:Culicidae) e na epidemiologia da malária

Sanchez-Ribas, Jordi; Parra-Henao, Gabriel; Guimarães, Anthony Érico
Fonte: Universidade de São Paulo. Instituto de Medicina Tropical de São Paulo Publicador: Universidade de São Paulo. Instituto de Medicina Tropical de São Paulo
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion; ; ; ; ; Formato: application/pdf
Publicado em 01/08/2012 ENG
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46.36%
Intervenções humanas como projetos de irrigação e usinas hidrelétricas, tem se transformado em graves problemas de saúde em muitos países, especialmente naqueles localizados nos trópicos. No presente artigo discutimos os efeitos que essas intervenções causam a dinâmica populacional dos anofelinos e nos padrões de transmissão de malaria. Foram revisados estudos feitos nas três principais regiões geográficas dos trópicos e sub-trópicos (África, Ásia e o Pacífico e Américas). Constatamos que os padrões da transmissão da malária antes da introdução dos empreendimentos, as medidas de controle, os movimentos demográficos, os padrões comportamentais das comunidades humanas e a bionomia dos anofelinos locais determinarão se o estabelecimento de campos de irrigação e/ou usinas hidrelétricas podem influenciar negativamente na saúde das pessoas. São apresentados exemplos de medidas de controle bem sucedidas nesses cenários. A utilização de Sistemas de Informação Geográfico tem sido destacada como uma importante ferramenta para subsidiar o estudo e controle da malária em áreas sob impacto ambiental.; Irrigation schemes and dams have posed a great concern on public health systems of several countries, mainly in the tropics. The focus of the present review is to elucidate the different ways how these human interventions may have an effect on population dynamics of anopheline mosquitoes and hence...

Irrigation technology for smallholder farmers: A strategy for achieving household food security in lower Gweru Zimbabwe

Dube,K.; Sigauke,E.
Fonte: South African Journal of Agricultural Extension Publicador: South African Journal of Agricultural Extension
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2015 EN
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The problem of food insecurity in developing countries is an enormous challenge. In rural communities, it is a perennial problem that requires undivided attention to ensure household food security. This paper seeks to define the role of rural participation in providing household and community food security with a particular focus on Lower Gweru irrigation project in Zimbabwe. The research comes in light of increased food deficit in Zimbabwe that has been compounded by failed politics, climate change and weather extreme events. Data was gathered using self-administered questionnaires, direct observation and literature review. Data was analysed using the Microsoft Excel 365 ToolPak and Health24 Web Calculator. This paper highlights the importance of rural irrigation schemes in addressing community and household food security and ensuring health nutrition uptake by irrigators and surrounding communities. Rural irrigation systems enable farmers to become net food sellers allowing them to benefit from food price volatility. It also highlights the resultant development and makes recommendations for future irrigation developments.

Factors affecting farmers' participation in irrigation schemes of the Lower Niger River Basin and Rural Development Authority, Kwara State, Nigeria

Adekunle,O. A; Oladipo,F. O.; Busari,I. Z.
Fonte: South African Journal of Agricultural Extension Publicador: South African Journal of Agricultural Extension
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2015 EN
Relevância na Pesquisa
56.51%
In Nigeria the performances of many governments owned irrigation schemes have fallen short of expectation. Management issues and steps required to ensure sustainable growth in irrigated agriculture were not given proper attention. This study therefore examined those factors affecting farmers' participation in irrigated agriculture at the Lower Niger River Basin Development Authority (LNRBDA) in Kwara State, Nigeria. One hundred and sixty (160) respondents were selected from communities around LNRBDA site at Oke Oyi for this study through a two-stage sampling procedures. Data collected were analyzed using descriptive statistics and logistic regression model. The result showed that majority of respondents were farmers within the economic active age and relatively literate. They identified factors affecting farmers' participation in the scheme to include poor knowledge of irrigation techniques(78.3%), Insufficient water for irrigation during the dry season (80.5%), high cost of labour (75.8%), Lack of access to credit facility (76.6%), poor response to farmers' needs by the Authority (85.2%), Irregular pumping of water (86.7),. Consequently, the study recommended encouragement of participatory irrigation scheme (PIM) in which farmers would take charge of daily allocation of water while the authority serves as supervisory body and stepping up of extension activities within the surrounding villages.

Water footprint of growing vegetables in selected smallholder irrigation schemes in South Africa

Nyambo,Patrick; Wakindiki,Isaiah IC
Fonte: Water SA Publicador: Water SA
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/07/2015 EN
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Crop water footprint (WF) is the volume of fresh water used to produce a certain crop in all the steps in the production line. The CROPWAT model was used to calculate crop evapotranspiration, differentiating green and blue water in Zanyokwe (ZIS), Thabina (TIS) and Tugela Ferry (TFIS) Irrigation Schemes. Green beans had the highest water footprint in all three irrigation schemes with 3 535.7 m³/t in TIS, 2 753 m³/t in TFIS and 2 407.6 m³/t in ZIS. Cabbage had the lowest water footprint. The highest water footprint for growing cabbage was 254.5 m³/t in TFIS, followed by 223.1 m³/t in TIS, and the lowest was 217.8 m³/t in ZIS. Green WF represented the highest percentage of water use at ZIS (50.5%), followed by blue water at 26.5% while grey water constituted 22.9%. At TFIS blue, green and grey water use was 23.1%, 56.7% and 20.2%, respectively. The differences observed in the WF of different crops and different schemes were attributed to the differences in weather and environmental characteristics. Green beans had the highest grey water footprint, i.e., 373 m³/t and the lowest was cabbage with 37 m³/t. Potato, spinach and tomatoes had footprints of 156 m³/t, 214 m³/t and 132 m³/t, respectively. For future research it is necessary to consider the possibility and trade-offs of shifting production of each crop to the places where it is most efficient...

Crop production management practices as a cause for low water productivity at Zanyokwe Irrigation Scheme

Fanadzo,M; Chiduza,C; Mnkeni,PNS; van der Stoep,I; Stevens,J
Fonte: Water SA Publicador: Water SA
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2010 EN
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56.51%
Generally, smallholder irrigation schemes (SIS) in South Africa have performed poorly and have not delivered on their development objectives of increasing crop production and improving rural livelihoods. Limited knowledge of irrigated crop production among farmers has been identified as one of the constraints to improved crop productivity, but research that investigates the relationship between farmer practices and productivity is lacking. A monitoring study was therefore conducted at the Zanyokwe Irrigation Scheme (ZIS) in the Eastern Cape to identify cropping systems and management practices used by farmers and to determine how these were related to performance. Evidence from 2 case studies showed that water management limited crop productivity. Irrigation application and system efficiencies were below the norm and irrigation scheduling did not take crop type and growth stage into account. Monitoring of 20 farmers over a 3-yr period showed that cropping intensity averaged only 48% and that the yields of the 2 main summer crops, grain maize (Zea mays L.) and butternut (Cucurbita moschata) averaged only 2.4 and 6.0 t·ha-1, respectively. In addition to poor water management, other main constraints to crop productivity were inadequate weed and fertiliser management and low plant populations. The results indicated that a lack of basic technical skills pertaining to irrigated crop production among farmers was a possible cause of inadequate management. In this regard...

Design implications on capital and annual costs of smallholder irrigator projects

Hards,A F; du Plessis,J A
Fonte: Journal of the South African Institution of Civil Engineering Publicador: Journal of the South African Institution of Civil Engineering
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/04/2013 EN
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While agricultural producers on commercially operated irrigation schemes will aim to achieve the recommended high crop yields, those on a smallholder irrigation scheme usually produce moderate to low crop yields. The water demand by these two irrigator types also differs and is reflected in the variations in crop yields. Because smallholder irrigators produce lower crop yields and use less water, they should use a system suited to this lower water demand. Many irrigation schemes have the opportunity for participants to assess their farming objectives and models. The irrigators can then use the assessment results to determine their water demands, reduce their infrastructure capacity and reduce their capital, operation and maintenance costs. On many smallholder schemes, the system has been designed for commercial crop yields and water use. If smallholders never achieve commercial levels of production, they have overcapitalised and subjected themselves to additional operational strain. In this study, six irrigation schemes based in the Eastern Cape were evaluated according to three levels of irrigation supply: a commercial irrigator, a smallholder irrigator and the commercial under-utilised irrigator. The irrigation infrastructure for each of the six schemes was designed...

Smallholder irrigation schemes in South Africa: a review of knowledge generated by the Water Research Commission

van Averbeke,W; Denison,J; Mnkeni,PNS
Fonte: Water SA Publicador: Water SA
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2011 EN
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The status and characteristics of the 302 smallholder irrigation schemes found in South Africa are discussed and knowledge on South African smallholder irrigation schemes generated by the Water Research Commission (WRC) over a period of nearly 20 years is reviewed. Themes covered include planning, design and technology; plot-holders and their livelihoods; institutions and organisations; support services; agronomic practices; and revitalisation. The availability of guidelines on most of these aspects is highlighted. Gaps in the knowledge of social, human and economic aspects of smallholder irrigation schemes are pointed out.