3 posts tagged “sustainable agriculture”

Link: Scientist who invented "virtual water" wins prize

The Stockholm International Water Institute awarded Professor John Anthony Allan (University of London, Britain) the 2008 Stockholm Water Prize for introducing the concept of "virtual water", a calculation method that takes into account the water embodied in foods and industrial products throughout their lifecycle.  For example, the 140 litres of water consumed to grow, process, package and ship the coffee beans required for a cup of water far outweighs the water that goes into the coffee maker. 

Wikipedia has a synopsis of the "virtual water" concept and lists the embodied water in a range of agricultural, household and industrial products.  For example:

• 1 kilogram of beef: 15,000 litres of water
• 1 kilogram of jeans: 10,850 litres of water
• a 1,100 kilogram car: 400,000 litres of water

Wikipedia lists three components that the calculations take into account:

• green water: rainwater evaporation
• blue water: surface or ground water evaporation
• grey water: water the becomes polluted during the process

At present, "virtual water" does not take into account whether water resources are being used in a sustainable manner or the degree of environmental impact.

Although "virtual water" can be used as a way of assessing the impact of different products on water resources, Allan's developed the concept to explain why water scarcity in regions such as the Middle East had not led to 'water wars (Watersheds and Problemsheds: Explaining the Absence of Armed Conflict Over Water in the Middle East).  Imports of products, particularly agricultural produce with a high embodied water content can represent a significant import of "virtual water", reducing the stress on local water supplies.  According to Virtual Water, 15% of the world's water usage is for export, with USA, Canada and Thailand the leading exporters and Sri Lanka, Japan and Netherlands the leading importers.  Allan argues "virtual water" should guide policy decisions, such as allocating water to products that "bring a sound return to water as well as sound returns to the economy" and increasing productive efficiency.

Link: Why long-haul food may be greener than local food with low air-miles

Times Online (UK) looked at the sustainability implications of choosing locally-grown food over imported food that is shipped large distances.  In many cases, the environmental impact of 'long-hauling' food was relatively small compared to other factors when the full life cycle of the food was taking into account.  Examples included the high energy cost of local hothouse tomatoes in Britain compared to those grown in Spain, or the additional fertilizer and electricity required to raise lambs in Britain when compared to New Zealand. 

Until proper Life Cycle Assessments can be developed, the article recommends a number of 'rules of thumb' where consumers can make a difference:

• reduce the amount of meat eaten - 90% of greenhouse gases are emitted during meat production, regardless of where that occurs
• avoid air-freighted food
• reduce packaging
• reduce waste
  

The article points out that there are no simple solutions to sustainability - it is critical to understand the overall system and determine which factors are significant contributors to unsustainability.  Agriculture can also have side-effects.  Many types of agriculture are high consumers of water, which can exacerbate drought conditions that in turn can impact hydro-electric power or curtail nuclear power production (Industries already affected by water stress, warns UN).

One factor that the article does not mention is the value of knowing where your food really comes from, and having a greater appreciation of how it is produced.  Having a direct connection with agriculture can influence how we act, and help protect an essential part of our lives.

Thanks to Jean-Francois Barsoum for the pointer!

Note: this is a public post

The Nature of Things (Canadian Broadcasting Corporation) did a two-part program on Cuba called “The Accidental Revolution”.  The first episode aired on July 30/2006 described the industrial system of agriculture introduced after the Castro revolution, a system heavily dependent on non-renewable energy for power and agricultural chemicals.  With the US embargo and the fall of the Soviet Union in 1989, energy imports dropped dramatically.  The ability to feed the people of Cuba declined significantly, with daily caloric intake dropping by a third (other reports suggest even more severe reductions).

Over the last decade, Cuba has embarked on developing sustainable agriculture that feeds the population while at the same time reducing agricultural energy inputs to 5% of what agriculture in other countries consumes.  The broadcast claimed that Canada expends 12 calories of non-renewable energy to produce a single calorie of food energy - the ratio is reversed in Cuba.

The program described the development of city farms, called ‘organoponicos’.  These not only reduce the cost of transporting the food to the consumer, but also provide green spaces, shade and improved air quality.  The farms produce a large variety of crops, with up to 50 different kinds of vegetables, fruits, coffee and both ornamental and medicinal plants.  The diversity of the city farms mimic nature, avoiding the problems of the more common monoculture practice.  Through intensive, year-round cultivation, yields of 15-20kg/square metre (28-37 lbs/square yard) are achieved.  All plant waste from the farms and neighbouring city are recycled through composting or earthworm humus.  Biological pest controls are used, such as lacewings, ladybugs, natural plant extracts, companion plants and specific bacteria.  

The last decade has also led to a renaissance in rural farming.  The approach is to work with nature, rather than controlling it.  Traditional tropical breeds of cattle with natural resistance to disease are highly prized.  Imported protein supplements have been replaced by combining grasslands with legumes, or a practice called ‘silvopasture’ that benefits from the 20-30% protein in some tree leaves.  As a result, the cost of producing milk has been cut in half.  Oxen are used to plough fields, reducing soil compaction.  Farmers work with agronomists to identify seeds that are naturally well adapted to local conditions, increasing plant diversity.  Seeds are freely traded between farmers, avoiding the cost of having to buy patented seeds.  As a result, food production has doubled with fewer chemicals.

The change to sustainable, organic agriculture has had social benefits.  ‘Organoponicos’ are designed to be profitable with few state controls – the result is that farmers are paid well.  In general, farming is seen as a desirable occupation, with the number of farmers growing.  Constraints on petroleum have eased in the past few years – the broadcast ends on a note of optimism that the Cuban commitment to sustainable agriculture will continue and be an example to other countries.  

More information can be found in the TreeHugger post Cuba's Organic Revolution, based on an article in The Independent via the Seattle Post-Intelligencer.