WATER QUALITY AND AGRICULTURAL WATER USE IN SOUTH AFRICA:
RESEARCH AND TECHNOLOGY TRANSFER ARC: PUBLIC SUPPORT SERVICES DIVISION
INTRODUCTION

One of the pillars of the ARC-PSS Division is to promote the sustainable management and use of the agricultural natural resources through research, technology development, technology transfer and scientific services. The ultimate objective of the research and development (R&D) is to increase the productive efficiency of agro-ecosystems. One of the key strategic focus areas of research and information generation is on 'Water quality and agricultural water use"

CURRENT RESEARCH/ACTIVITIES RELATED TO WATER QUALITY
The following are some of the main research focus areas and activities being carried out within the ARC-PSS division:

1. Assessment of the effect of different water qualities on crop production. The study focuses on the constraints and types of crop that can be grown in a study area (near Blesbokspruit) as part of the Grootvlei Desalinisation Project. '

2. The effect of Wetland systems and Goldmine effluent water use on irrigated agriculture. The project evaluates the Blesbokspruit wetlands with respect to pollution from industrial, mining and sewerage discharges.

3. Water quality analysis for agricultural use in rural areas of the Eastern Cape. KwaZulu Natal and the Western Cape provinces. The Analytical laboratory at the Institute for Soil, Climate and Water (ISCW) analysed over 250 samples for water quality during 2005 for the DoA (Water Use and Irrigation Development Directorate). The water is from boreholes used for both domestic and agricultural production. During 2006/07, 300 samples are likely to be analysed for Mpumalanga and Gauteng provinces.

4. Assessment of Water Quality and land degradation in Wetland areas. The Institute for Soil, Climate and Water has established a working group which will focus on "Conservation of Wetlands". During 2005, iln the Eastern Cape Province, an awareness project was conducted at Umthatha catchment Dam. Three more proposals have been submitted for 2006/07 for Gauteng, and the Eastern Cape Provinces to rehabilitate wetlands and assess water quality in these wetland lands.

5. Impact of water quality in Irrigation schemes. This is an on-going project which deals with assessing water quality in irrigation schemes under the RESIS programme in the Limpopo Province

6. Soil-Crop-Water quality studies ie. Monitoring the effect of water quality and soil and land productivity. Under this project, the emphasis is to evaluate the water quality degradation in our river systems and its impact on soil erosion, crop and grazing land

7. Water quality analysis for SA DC countries: As part of our international and SADC obligations, ISCW analytical laboratory is involved in various projects in water quality analysis as follows:

·         Zambia (26 samples received from Dept of Water affairs);

·         Lesotho (samples from Lesotho Highlands project);

·         Botswana (samples received from mining company)


8. Rain water harvesting project. Since water is a scarce resource, ISCW embarked on developing methods and technologies to improve the retention of rain water based on In-field water harvesting technologies. New projects have been initiated to look into other rain water harvesting technologies such as water from roofs and roads which can be used for agricultural purposes.

9. Conservation agriculture including land care projects. Technologies which conserve soil and water have been developed and transferred to various farmers in KwaZulu Natal, Limpopo and the Eastern Cape province.

During 2005/06, the ISCW received recognition in water related projects by receiving the following awards: The KwaMhlanga LandCare project, for which ISCW is the main service provider, was awarded a trophy for the best overall LandCare project in Mpumalanga, as the project implementing most LandCare principles; the water harvesting group based in the Free State Province was one of the five National Science and Technology Forum Award finalists in the category for organizations that have made an outstanding contribution towards science, engineering and technology over the last 10 years

CHALLENGES AND FUTURE ACTIVITIES

Soil salinity is a major problem that affects virtually all of the major irrigation schemes in South Africa. With the increased use of the water resources, the salinity level in the rivers is bound to rise in future and this is likely to exacerbate the extent of the problem. Through return flow to river systems, irrigation itself may contribute to this hazard.

Two flagship awareness campaigns of national agricultural and environmental importance in which the ARC-PSS division actively participated, are climate change and the conservation of wetlands. Climate change is one of the currently key scientific and policy issues of great concern as perturbations in climate parameters could be largely amplified by adding to the already high risk and stressed water resources and to socio-economic well-being. In addition to its natural resource conservation, ISCW has initiated activities to improve wetlands and water quality management

Wetlands can be regarded as the biological congregation where water and land overlap. Wetlands act as natural water harvesting points and therefore constitute a valuable agricultural resource with significant benefits in terms of food security, health and income. The unsustainable management and utilization of wetlands, however, is bound to contribute to the loss in natural capital with harmful consequences for peoples' livelihoods. Best practices must therefore be identified and developed so that wetland management can be tailored to landscape conditions and potential. One of the major constraints to the sustainable use and management of wetlands is insufficient knowledge or the lack of knowledge.

Gold mining activities in the Witwatersrand area have created certain concerns about the radio active pollution of the river systems in that area since the early 90s. The possible presence of Uranium in the river systems of the said area, amongst others, is presumed to be from sediments of the mining activities or through decanting of ground water (Dolomite aquifer).

Screening surveys of radioactivity in the Mooi River catchment were conducted by the Institute of Water Quality Studies (IWQS) of the Department of Water Affairs and Forestry in 1995 and 1996. Elevated levels of radionuclide of uranium and radium were detected in streams close to mining activities.
In terms of the results of this study, it was found that although the great majority of sampling sites in the catchments showed low levels of water born radionuclide, the sites that showed significant concentrations of water born radionuclide were associated with discharges of mine water into the river system, while the levels of radioactivity in the water column declined with distance from the mining operations.

In view of the fact that there are irrigation areas downstream of Mooi river and many other rivers in the Witwatersrand areas, associated with gold mining activities, the more detailed investigations as stipulated above, should cover the impact of such risks to humans through consumption of agricultural products from these schemes.

The following could form part of a nationwide research agenda in order to find solutions due to increasing water demand and increasing water quality degradation:

 

·         Research in water quality degradation to establish the extent of degradation in our river systems, wetlands and irrigation schemes.

 

·         Soil-crop-water quality studies with emphasis on developing monitoring tools/technologies and assessing impacts of soil erosion, mining and water from industries

 

·         Development of water quality monitoring tools and guidelines due to return flow from irrigation, mining and industries

 

·         Establishment of a comprehensive country wide water quality monitoring network