With huge quantities of water being used in food production, Ian Booth, Technical Director of Reynolds Catering Supplies, provides an overview of some of the key issues relating to water management within the fresh produce industry, with particular focus on the concept of Water Footprinting.
Approximately eighty five percent of humanities water footprint is related to consumption of agricultural produce, ten per cent relates to industrial products and only five per cent to domestic water consumption1. It is widely accepted that the long-term sustainability of water is in doubt in many regions of the world. Within an article from the Independent the following was explained; Water use has been growing far faster than the number of people. During the 20th century the world population increased fourfold, but the amount of freshwater that it used increased nine times over. Already 2.8 billion people live in areas of high water stress, and this will rise to 3.9 billion more than half the expected population of the world by 2030. The Food and Agriculture Organisation of the United Nations (FAO) also states that a number of regions are already chronically short of water.
Both water quantity and water quality are becoming dominant issues in many countries. Problems relate to poor water allocation and pricing, inefficient use, and lack of adequate integrated management. To keep up with demand, and shifting dietary demands, the FAO predicts that by 2040 that the irrigated area will need to be increased by 34per cent in developing countries. Most of the water used by industries and municipalities is often returned to watercourses degraded in quality. Agricultural irrigation is responsible for nearly 40 per cent of world food production, uses about 70 per cent of total water withdrawals (90 per cent in the dry tropics)3. Groundwater, which supplies one third of the worlds population, is increasingly being used for irrigation. Water tables are being lowered in many areas making it more difficult and therefore expensive to access.
It is clear from the above statements that out of all of the users of water, agriculture has the largest potential for contributing to integrated water management through the use of environmental practices. For this reason, those involved the production or supply of food products have a responsibility to ensure suitable integrated management of water supplies.
Within this article, some of the options available are discussed, as well as examples within the fresh produce industry. As a responsible Fresh Produce company within the Food Service sector, at Reynolds we are gaining a wider appreciation of the impact of water usage and how we can provide an influence within this area. As part of our Environmental Management System (EMS) we monitor the aspects and impacts to the environment of our practices. As we have built the EMS and rooted the internal practices and procedures within the company, we have the ability to then focus further back into the supply chain. We work with both local producers, where as a company we support where needed in best practice and produce assurance, as well as with producers who also supply into retail and have a range of produce assurance standards in place. As we have progressed within our investigations into both Carbon and Water footprinting, it is clear that producers and the structure supporting them through cooperatives, agents and importers have a wide appreciation of the affect of water management on both the environment and their business.
Within the 2006 FAO report compiled on behalf of the UN Water Task Force, a number of strategies were outlined for water conservation and management.
Improved on farm water management
Improving the performance of irrigation systems services
Augmenting supply: the use of non-conventional waters
National Policies: water allocation to agriculture
Trade as a variable in agriculture water management
Some examples of how the supply base have implemented these practices are briefly outlined below. Obviously the space available within the article has limited the detail, but the author would be pleased to provide further information to support this as required.
Within the industry, water usage is starting to have a similar profile to that of Carbon Footprinting. It is expected that the consumer will soon start to demand more assurance within this area. Water Footprinting is a term being more widely used within the industry. A Water Footprint has been described as the amount of water consumed, directly or indirectly, by consuming a set of products, generally expressed in cubic metres of water per consumption group e.g. a nation, a business or an individual.
Water footprinting is increasingly being used to understand the impact of certain crops on the environment and follows a similar philosophy to Carbon Footprinting. When the water required for production of food is considered it can be an eye opening experience; the Water Footprint Network4 have calculated the water requirements for a range of products. To produce a Kilo of beef requires 15500 litres of water, 1300 litres for a kilo of Barley and 70 litres for one apple.
As a fresh produce supplier, the consumption of fruit and vegetables is highly recommended! However, a pizza margherita and a glass of wine has a similar water footprint to two apples. Maybe this makes the decision more difficult!
Integrated Water Management within the Supply Chain
A key area to identify is the regions with water a shortage against the type and quantity of products being grown. This also needs to be linked to a holistic view. As previously debated with air freight and food miles, the socio-economic perspective of the location need to be considered. The aim would be to continue sourcing from the region but then work on ways to improve the water management. The focus should be to understand the water usage issues within the region i.e. including the type of soil; sandy soils will retain water at a different rate to a clay soil. One rule does not fit all and each requires a different policy and risk assessment for water management.
Although produce quality assurance schemes often have an element of water management, currently policies relating to water management are generally company specific, or led by expertise within a county or region.
At the grower level there are many factors which can be considered within water control. An accurate and consistent system for measuring water usage enables specific application based on a field or plot. By use of a computerized program specific to a crop, electronic measurement of the water content through probes placed in the soil can ensure an accurate and constant level of water supply.
Irrigation techniques are also trending towards the use of sub soil irrigation rather than spray, where the application can be targeted, especially at root level. This can also enable controlled fertigation (the application of fertilisers, soil amendments, or other water soluble products).
Part of the science of agronomy is to understand how a crop grows, including the effect of water usage on yield. Part of the science of agronomy is to understand how a crop grows, including the effect of water usage on quality and yield. Planning water management around crop growth can optimize quality and yield, by focusing irrigation on crop specific critical key watering points.
As well as application, collection of irrigation also has to be considered. Bankings and Run-offs can be used to retain water or collect in preparation for dryer months. Glass house systems can be virtually self sufficient, UK strawberry growers catch rain water from the roof and channel this to storage tanks. Dutch tomato producers convert oil run generators into CO2, water and electricity (light and heat during the winter months), all needed within the growth cycle, and excess electricity is sold to the national grid.
As well as sourcing irrigation water, conservation is also key. Moisture loss prevention techniques may include increasing the surface area of the soil to reduce run off or evaporation. An example of this is mulch which is still a method which is under utilised. This can also increase nutrient availability.
As well as the use of conventional water sources, there is an appreciation of the potential of unconventional methods. Desalination plants may be used although can be expensive and generally funded through government initiatives. Other examples include exploitation of deep groundwater, aquifers for storage of surplus water, atmospheric water (fog and cloud) harvesting and iceberg water utilization. Suitable standards of solids and salinity will need to be considered. Brackish water and sewage effluents may be used for irrigation, although risks to human health may result if not managed properly.
As a business, Reynolds are currently working with Writtle College to gain a further understanding of the positive impact that we are able to have through our ongoing sourcing strategies and working with a supplier base who recognises and actively improves the water management practices used.
The author wishes to thank Mark Baxter of Wealmoor Ltd for his support in writing this article.
1 The Water Footprint: Water in the Supply Chain. A Hoekstra. The Environmentalist. March 2010.
2 Water scarcity: G. Lean, The Independent, March 2009.
3 Water Monitoring Mapping Existing Global Systems & Initiatives. Background Document. Prepared by FAO on behalf of the UN-Water Task Force on Monitoring, August 2006.
4 Water Footprint Network (info-at- waterfootprint.org, Water Footprint Network c/o University of Twente, Horst Building, P.O. Box 217, 7500 AE Enschede, The Netherlands.the use of