Comparing the usefulness and applicability of different water footprint methodologies for sustainable water management in agriculture

The lack of sustainability of our water resources threatens food security in many places worldwide. Different water footprint (WF) methodologies were investigated for their ability to improve water management at various scales. Methodologies according to the Water Footprint Network (WFN), life cycle assessment (LCA) and hydrological‐based approaches were assessed, and a working example is given for apples produced in South Africa. A fundamental viewpoint was defined and the knowledge hierarchy applied to investigate the approaches and information generated. WFs reported simply as a volume of water used per mass of crop produced cannot indicate the sustainability of the water use unless interpreted within the local hydrological and environmental context. The WFN methodology appears most useful to resource managers due to its quantitative nature and ability to compare blue and green water consumption versus water availability. The LCA approach may be best for comparisons of the impact of different products. None of the methodologies provides a single metric that can be used to inform wise consumer choices as it is not possible to incorporate all the complexities associated with water use into a single number that can be used to inform sustainable water use.The Water Research Commission (WRC project No. K5/2273//4: Water footprint of selected vegetable and fruit crops produced in South Africa). The first author, Betsie le Roux, received financial support for research from the WRC and a bursary from the National Research Foundation (NRF) of South Africa (NRF Grant number: 88572).https://onlinelibrary.wiley.com/journal/153103612019-12-01hj2019Plant Production and Soil Scienc

Water footprints of vegetable crop wastage along the supply chain in Gauteng, South Africa

Food production in water-scarce countries like South Africa will become more challenging in the future because of the growing population and intensifying water shortages. Reducing food wastage is one way of addressing this challenge. The wastage of carrots, cabbage, beetroot, broccoli and lettuce, produced on the Steenkoppies Aquifer in Gauteng, South Africa, was estimated for each step along the supply chain from the farm to the consumer. Water footprints for these vegetables were used to determine the volume of water lost indirectly as a result of this wastage. Highest percentage wastage occurs at the packhouse level, which is consistent with published literature. Some crops like lettuce have higher average wastage percentages (38%) compared to other crops like broccoli (13%) and cabbage (14%), and wastage varied between seasons. Care should therefore be taken when applying general wastage values reported for vegetables. The classification of “waste” presented a challenge, because “wasted” vegetables are often used for other beneficial purposes, including livestock feed and composting. It was estimated that blue water lost on the Steenkoppies Aquifer due to vegetable crop wastage (4 Mm3 year-1) represented 25% of the estimated blue water volume that exceeded sustainable limits (17 Mm3 year-1).The Water Research Commission (WRC project No. K5/2273//4). The first author, Betsie le Roux, received financial support for research from the WRC and a bursary from the National Research Foundation (NRF) of South Africa (NRF Grant number: 88572).http://www.mdpi.com/journal/wateram2019Plant Production and Soil Scienc

Estimating water footprints of vegetable crops : influence of growing season, solar radiation data and functional unit

Water footprint (WF) accounting as proposed by the Water Footprint Network (WFN) can potentially provide important information for water resource management, especially in water scarce countries relying on irrigation to help meet their food requirements. However, calculating accurate WFs of short-season vegetable crops such as carrots, cabbage, beetroot, broccoli and lettuce presented some challenges. Planting dates and inter-annual weather conditions impact WF results. Joining weather datasets of just rainfall, minimum and maximum temperature with ones that include solar radiation and wind-speed affected crop model estimates and WF results. The functional unit selected can also have a major impact on results. For example, WFs according to the WFN approach do not account for crop residues used for other purposes, like composting and animal feed. Using yields in dry matter rather than fresh mass also impacts WF metrics, making comparisons difficult. To overcome this, using the nutritional value of crops as a functional unit can connect water use more directly to potential benefits derived from different crops and allow more straightforward comparisons. Grey WFs based on nitrogen only disregards water pollution caused by phosphates, pesticides and salinization. Poor understanding of the fate of nitrogen complicates estimation of nitrogen loads into the aquifer.The first author, Betsie le Roux, conducted this research and wrote the paper as part of her Ph.D. studies; Michael van der Laan supervised the research.The Water Research Commission (WRC) and the National Research Foundation (NRF) of South Africa.http://www.mdpi.com/journal/wateram2017Plant Production and Soil Scienc

We cannot continue like this

The book is based on the view that the present trajectory of modern development cannot continue as it is now because it is ecologically unsustainable, it continues to enlarge the gap between rich and poor, and the decolonialisation movement has drawn our attention again to the specific role of religion, culture and value in human affairs and the need for a robust element of indigenisation and contextualisation. This book is strongly focused on the context of Africa, with two chapters that are written by authors from the Netherlands, for the purpose of presenting a North-South dialogue. The book contains reflection on approaches followed in building sustainable human communities in general and reflection on specific efforts to solve sustainability issues. It seeks to integrate academic reflection and insights gained from practical involvement with sustainability issues in local communities and low-income households, with contributions from Theology and Natural and Social Sciences

Water Footprints of Vegetable Crop Wastage along the Supply Chain in Gauteng, South Africa

Food production in water-scarce countries like South Africa will become more challenging in the future because of the growing population and intensifying water shortages. Reducing food wastage is one way of addressing this challenge. The wastage of carrots, cabbage, beetroot, broccoli and lettuce, produced on the Steenkoppies Aquifer in Gauteng, South Africa, was estimated for each step along the supply chain from the farm to the consumer. Water footprints for these vegetables were used to determine the volume of water lost indirectly as a result of this wastage. Highest percentage wastage occurs at the packhouse level, which is consistent with published literature. Some crops like lettuce have higher average wastage percentages (38%) compared to other crops like broccoli (13%) and cabbage (14%), and wastage varied between seasons. Care should therefore be taken when applying general wastage values reported for vegetables. The classification of “waste” presented a challenge, because “wasted” vegetables are often used for other beneficial purposes, including livestock feed and composting. It was estimated that blue water lost on the Steenkoppies Aquifer due to vegetable crop wastage (4 Mm3 year−1) represented 25% of the estimated blue water volume that exceeded sustainable limits (17 Mm3 year−1)

Estimating Water Footprints of Vegetable Crops: Influence of Growing Season, Solar Radiation Data and Functional Unit

Water footprint (WF) accounting as proposed by the Water Footprint Network (WFN) can potentially provide important information for water resource management, especially in water scarce countries relying on irrigation to help meet their food requirements. However, calculating accurate WFs of short-season vegetable crops such as carrots, cabbage, beetroot, broccoli and lettuce presented some challenges. Planting dates and inter-annual weather conditions impact WF results. Joining weather datasets of just rainfall, minimum and maximum temperature with ones that include solar radiation and wind-speed affected crop model estimates and WF results. The functional unit selected can also have a major impact on results. For example, WFs according to the WFN approach do not account for crop residues used for other purposes, like composting and animal feed. Using yields in dry matter rather than fresh mass also impacts WF metrics, making comparisons difficult. To overcome this, using the nutritional value of crops as a functional unit can connect water use more directly to potential benefits derived from different crops and allow more straightforward comparisons. Grey WFs based on nitrogen only disregards water pollution caused by phosphates, pesticides and salinization. Poor understanding of the fate of nitrogen complicates estimation of nitrogen loads into the aquifer

Status and prospects of life cycle assessments and carbon and water footprinting studies in South Africa

PURPOSE : Using the current state of life cycle assessment (LCA), carbon and water footprinting, and EPDs in South Africa, this work explores the challenges and opportunities for scholarly development in these areas in the country. METHODS : Being a relatively small LCA community in South Africa, academics, consultants, and other stakeholders were approached to provide lists of known studies, with further reports, that may have been missed, obtained through internet searches. Information was collated on database development, capacity building, and other aspects and presented here in a single paper. RESULTS AND DISCUSSION : While the authors are aware of companies working on LCA and related studies, hidden in confidential reports, we were able to find 27 LCA, 17 water and 12 carbon footprinting, and 10 EPD studies. Although these studies have potential advantages for policymaking and business, their number, implementation, and impact remain limited. CONCLUSION : While previously seen as an academic exercise, life cycle thinking has been adopted by industry, private consultants, and the South African National Cleaner Production Centre (NCPC-SA), among others. Growing interest has led to the creation of several training courses available at academic institutes, the NCPC-SA, and consulting firms, ranging from the basic understanding to advanced use of software packages and modeling techniques. The development of a national LCI database and further exposure and opportunity for LCA studies are important steps to hopefully spur LCA in Southern Africa in the future.http://link.springer.com/journal/113672021-11-16hj2021Plant Production and Soil Scienc