scholarly journals A preliminary investigation of the water use efficiency of sweet sorghum for biofuel in South Africa

Water SA ◽  
2016 ◽  
Vol 42 (1) ◽  
pp. 152 ◽  
Author(s):  
MG Mengistu ◽  
JM Steyn ◽  
RP Kunz ◽  
I Doidge ◽  
HB Hlophe ◽  
...  
Keyword(s):  
South Africa ◽  
Water Use Efficiency ◽  
Water Use ◽  
Sweet Sorghum ◽  
Preliminary Investigation ◽  
Use Efficiency

scholarly journals Analysis of virtual water flows associated with the trade of maize in the SADC region: importance of scale

2009 ◽  
Vol 13 (10) ◽  
pp. 1967-1977 ◽  
Author(s):  
J. M. Dabrowski ◽  
E. Masekoameng ◽  
P. J. Ashton
Keyword(s):  
South Africa ◽  
Water Use Efficiency ◽  
Water Content ◽  
Water Use ◽  
Water Scarcity ◽  
Virtual Water ◽  
Blue Water ◽  
Maize Production ◽  
Water Flows ◽  
Use Efficiency

Abstract. The concept of virtual water encourages a country to view agricultural crops in terms of the amount of water required to produce those crops, with a view to implementing trading policies that promote the saving of scarce water resources. Recently, increased attention has focussed on partitioning the virtual water content of crops into green and blue water (derived from rainfall and irrigation, respectively) as the latter has higher opportunity costs associated with its use and therefore impacts directly on scarcity. Maize is the most important crop traded within the SADC region. South Africa is the largest producer and exporter of maize, with the majority of its exports destined for other SADC countries. In comparison to other SADC countries, South Africa produces maize relatively efficiently, with a low virtual water content and a high green (868 m3 t−1) to blue (117 m3 t−1) water ratio. The blue water content is however higher than for maize produced in all other SADC countries, with the exception of Namibia (211 m3 t−1). Current trade patterns therefore result in a net expenditure of blue water (66×106 m3), almost all of which is exported by South Africa (65×106 m3). South Africa is one of the most water scarce countries in the region and analysis of virtual water flows indicates that current SADC maize trading patterns are influenced by national productivity as opposed to water scarcity. The virtual water content of maize was estimated for each of South Africa's nineteen Water Management Area's (WMA) and used as a proxy to represent water use efficiency for maize production. The virtual water content varied widely across all of the WMAs, ranging from 360 m3 t−1 in the Ustutu Mhlatuze to 1000 m3 t−1 in the Limpopo. A comparison of the virtual water content and production of maize (expressed as a percentage of the total national production) identified those WMAs where maize production is highly water inefficient (e.g. Lower Orange and Limpopo WMAs). Results suggest that, while a national estimate of the virtual water content of a crop may indicate a relatively efficient use of water, an analysis of the virtual water content at smaller scales can reveal inefficient use of water for the same crop. Therefore, analysis of the virtual water content of crops and trading of agricultural products at different spatial scales (i.e. regional, national and WMA) could be an important consideration within the context of water allocation, water use efficiency and alleviation of water scarcity.

scholarly journals Implications of water policy reforms for virtual water trade between South Africa and its trade partners: economy-wide approach

Water Policy ◽  
2014 ◽  
Vol 17 (4) ◽  
pp. 649-663 ◽  
Author(s):  
Rashid Hassan ◽  
Djiby Racine Thiam
Keyword(s):  
South Africa ◽  
Water Use Efficiency ◽  
Water Use ◽  
Water Policy ◽  
Virtual Water ◽  
Policy Reforms ◽  
Virtual Water Trade ◽  
Agricultural Exports ◽  
Recent Trends ◽  
Use Efficiency

This paper employs an economy-wide framework to evaluate impacts of water and trade policy reforms in South Africa (SA) on virtual water flows. To pursue this analysis, the study derives net virtual water trade flows between SA and its partners to assess implications of recent trade agreements within the South African Development Community compared to economic cooperation with other major trading blocks (e.g. European Union, Asia, and Brazil, Russia, India and China (BRIC)). Recent trends in actual trade confirm model predictions that liberalization of water allocation would switch water from field crops to horticulture and promote growth in non-agricultural exports. The results suggest that it is necessary to introduce policies that enhance likely outcomes of liberalization promoting higher water use efficiency within irrigation agriculture such as increased adoption of more efficient irrigation methods (sprinkler, drip, etc.) as water becomes more expensive under wider open competition. Moreover, investment in higher water use efficiency and improved competitiveness of dryland agriculture therefore represent the sound economic options for strengthening the capacity to achieve food security objectives as the country strives to lower net water exports. Finally, careful coordination of trade and water policy reforms is another necessary challenge for SA's strive to manage a water stressed economy.

scholarly journals Eucalyptusand Water Use in South Africa

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Janine M. Albaugh ◽  
Peter J. Dye ◽  
John S. King
Keyword(s):  
South Africa ◽  
Water Use Efficiency ◽  
Water Use ◽  
Canopy Structure ◽  
Wood Products ◽  
Future Research ◽  
Physiological Processes ◽  
Wide Range ◽  
Use Efficiency ◽  
Use Studies

TheEucalyptusgenus yields high rates of productivity and can be grown across a wide range of site types and climates for products such as pulp, fuelwood, or construction lumber. In addition, many eucalypts have the ability to coppice, making this genus an ideal candidate for use as a biofuel feedstock. However, the water use ofEucalyptusis a controversial issue, and the impacts of these fast-growing trees on water resources are well documented. Regardless, the demand for wood products and water continues to rise, providing a challenge to increase the productivity of forest plantations within water constraints. This is of particular relevance for water-limited countries such as South Africa which relies on exotic plantations to meet its timber needs. Research results from water use studies in South Africa are well documented and legislation restrictions limit further afforestation. This paper outlines techniques used to quantify the water use of eucalypt plantations and provides recommendations on where to focus future research efforts. Greater insights into the water use efficiency of clonal material are needed, as certain eucalypt clones show fast growth and low water use. To better understand water use efficiency, estimates should be combined with monitoring of stand canopy structure and measurements of physiological processes.

scholarly journals Analysis of virtual water flows associated with the trade of maize in the SADC region: importance of scale

2008 ◽  
Vol 5 (5) ◽  
pp. 2727-2757 ◽  
Author(s):  
J. M. Dabrowski ◽  
E. Masekoameng ◽  
P. J. Ashton
Keyword(s):  
South Africa ◽  
Water Use Efficiency ◽  
Water Content ◽  
Water Use ◽  
Water Scarcity ◽  
Virtual Water ◽  
Blue Water ◽  
Maize Production ◽  
Water Flows ◽  
Use Efficiency

Abstract. The concept of virtual water encourages a country to view agricultural crops in terms of the amount of water required to produce those crops, with a view to implementing trading policies that promote the saving of scarce water resources. Recently, increased attention has focussed on partitioning the virtual water content of crops into green and blue water (derived from rainfall and irrigation, respectively) as the latter has higher opportunity costs associated with its use and therefore impacts directly on scarcity. Maize is the most important crop traded within the SADC region. South Africa is the largest producer and exporter of maize, with the majority of its exports destined for other SADC countries. In comparison to other SADC countries, South Africa produces maize relatively efficiently, with a low virtual water content and a high green (868 m3 tonne−1) to blue (117 m3 tonne−1) water ratio. The blue water content is however higher than for maize produced in all other SADC countries, with the exception of Namibia (211 m3 tonne−1). Current trade patterns therefore result in a net expenditure of blue water (66×106 m3), almost all of which is exported by South Africa (65×106 m3). South Africa is one of the most water scarce countries in the region and analysis of virtual water flows indicates that current SADC maize trading patterns are influenced by national productivity as opposed to water scarcity. The virtual water content of maize was estimated for each of South Africa's nineteen Water Management Area's (WMA) and used as a proxy to represent water use efficiency for maize production. The virtual water content varied widely across all of the WMAs, ranging from 360 m3 tonne-1 in the Ustutu Mhlatuze to 1000 m3 tonne−1 in the Limpopo. A comparison of the virtual water content and production of maize (expressed as a percentage of the total national production) identified those WMAs where maize production is highly water inefficient (e.g. Lower Orange and Limpopo WMAs). Results suggest that, while a national estimate of the virtual water content of a crop may indicate a relatively efficient use of water, an analysis of the virtual water content at smaller scales can reveal inefficient use of water for the same crop. Therefore, analysis of the virtual water content of crops and trading of agricultural products at different spatial scales (i.e. regional, national and WMA) could be an important consideration within the context of water allocation, water use efficiency and alleviation of water scarcity.

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