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The environmental impact and sustainability of irrigation with coal-mine water

Thesis (PhD)--University of Pretoria, 2009.

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Other Authors: Annandale, John George
Format: Thesis
Published: University of Pretoria 2013
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access_status_str Open Access
author2 Annandale, John George
author_browse Annandale, John George
author_facet Annandale, John George
collection Thesis
dc_rights_str_mv © University of Pretoria 2008
description Thesis (PhD)--University of Pretoria, 2009.
format Thesis
id oai:repository.up.ac.za:2263/24935
institution University of Pretoria (South Africa)
last_indexed 2026-06-10T12:37:14.131Z
license_str Other — see source repository
provenance_str_mv Harvested via OAI-PMH from UPSpace — University of Pretoria Institutional Repository
publishDate 2013
publishDateRange 2013
publishDateSort 2013
publisher University of Pretoria
publisherStr University of Pretoria
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source_str UPSpace — University of Pretoria Institutional Repository
spelling oai:repository.up.ac.za:2263/24935 The environmental impact and sustainability of irrigation with coal-mine water Annandale, John George Steyn, Joachim Marthinus yaco@tuks.co.za Beletse, Yacob Ghebretinsae Irrigation Swb model Modelling Soil salinity Caso4 Gypsiferous water Na2so4 Nahco3 Sustainability Coal-mine water Environmental impact UCTD Thesis (PhD)--University of Pretoria, 2009. The environmental impact and sustainability of irrigation with coal-mine water was investigated from an agricultural point of view on different coal-mines in the Republic of South Africa. Field trials were carried out on a commercial and plot scale, on sites that could offer a range of soil, crop, weather conditions and water qualities such as gypsiferous, sodium sulphate and sodium bicarbonate waters. Crop production under irrigation with gypsiferous mine water is feasible on a field scale and sustainable if properly managed. No symptoms of foliar injury due to centre pivot sprinkler irrigation with gypsiferous water were observed. The presence of high Ca and Mg in the water suppressed plant uptake of K. This could be corrected by regular application of K containing fertilizers. The bigger problem experienced was waterlogging due to poor site selection, especially during the summer months. The problem is not related to the chemistry of the gypsiferous water used for irrigation. Pasture production with Na2SO4 rich mine effluent was also feasible, at least in the short term, but would need a well-drained profile and large leaching fraction to prevent salt build up. Forage quality was not affected by the Na2SO4 water used. NaHCO3 water was of very poor quality for irrigation and is not recommended for irrigation. Salt tolerant crops that are not susceptible to leaf scorching can be produced with this water, but only with very high leaching fractions and careful crop management. Regular gypsum application will be required to prevent structural collapse of the soil. Most of the salts applied will leach from the soil profile, and will probably need to be intercepted for treatment or reuse. The Soil Water Balance (SWB) model was validated successfully. The model predicted crop growth, soil water deficit to field capacity and soil chemistry reasonably well, with simulated results quite close to measured values. Soluble salts have to be leached from the soil profile, so that crop production can be sustainable, but will externalize the problem to the receiving water environment. To assess the environmental impact of irrigation with coal-mine water, it is valuable to develop a tool that can assist with prediction of offsite effects. SWB was validated for runoff quantity and quality estimations, and was found to give reasonable estimates of runoff quantity and quality. SWB also predicted the soil water and salt balance reasonably well. This gives one confidence in the ability of the model to simulate the soil water and salt balance for long-term scenarios and link the output of SWB to ground and surface water models to predict the wider impact of large scale irrigation. This will also link the findings of this work to other research oriented towards the management of mine water and salt balances on a catchment scale. It will also help authorities make informed decisions about the desirability and consequences of permitting mine water irrigation on a large scale. Irrigation with gypsiferous mine water can be part of finding the solution to surplus mine water problems. Appropriate irrigation management of mine water is essential for the long-term sustainability of irrigation. Plant Production and Soil Science unrestricted 2013-09-06T18:53:03Z 2009-06-03 2013-09-06T18:53:03Z 2009-04-23 2009-06-03 2009-05-24 Thesis Beletse, YG 2008, The environmental impact and sustainability of irrigation with coal-mine water, PhD thesis, University of Pretoria, Pretoria, viewed yymmdd < http://hdl.handle.net/2263/24935 > D622/ag http://hdl.handle.net/2263/24935 http://upetd.up.ac.za/thesis/available/etd-05242009-125253/ © University of Pretoria 2008 application/pdf application/pdf application/pdf application/pdf application/pdf application/pdf application/pdf application/pdf application/pdf application/pdf University of Pretoria
spellingShingle Irrigation
Swb model
Modelling
Soil salinity
Caso4
Gypsiferous water
Na2so4
Nahco3
Sustainability
Coal-mine water
Environmental impact
UCTD
The environmental impact and sustainability of irrigation with coal-mine water
title The environmental impact and sustainability of irrigation with coal-mine water
title_full The environmental impact and sustainability of irrigation with coal-mine water
title_fullStr The environmental impact and sustainability of irrigation with coal-mine water
title_full_unstemmed The environmental impact and sustainability of irrigation with coal-mine water
title_short The environmental impact and sustainability of irrigation with coal-mine water
title_sort environmental impact and sustainability of irrigation with coal mine water
topic Irrigation
Swb model
Modelling
Soil salinity
Caso4
Gypsiferous water
Na2so4
Nahco3
Sustainability
Coal-mine water
Environmental impact
UCTD
url http://hdl.handle.net/2263/24935
http://upetd.up.ac.za/thesis/available/etd-05242009-125253/