Land use and soil degradation

Date : 22 October 2013

What’s the issue?

Land use and soil degradationOne way that mankind has kept pace with the growing demand for food is to bring more farmland in to production. However, almost all of the world’s naturally fertile land is now in use. The scope to expand this further is very limited.

New farmland is being created by clearing forests but this of course is a major contributor to atmospheric CO2 and so is not a sensible option.

Growing food demand will therefore need to be met from broadly the same footprint of land, requiring higher yields and less wastage. This challenge would become even greater if further agricultural land is converted to biofuels, or indeed to any other use.

Farm yields are dependent on the quality of topsoil, a thin layer of about 6 inches which contains critical organic matter and nutrients and also holds and supplies water to plant roots. It is vital that this layer is maintained.

A degree of soil erosion, resulting from water, wind and ice, occurs naturally but tends to be compensated by new soil as vegetation decays. However, unsustainable farming practices can undermine the balance, as occurred in the US Great Plains in the 1930’s when land was cleared of vegetation and over-ploughed, leaving it susceptible to dust storms.

According to the Earth Policy Institute, nearly a third of the world’s topsoil is eroding faster than its rate of replenishment and is therefore reducing in fertility. From a global perspective, this is one of the biggest threats to future food security.

Soils are also vulnerable to future climate change. Rising temperatures can reduce soil organic matter and weaken soil structure. Stormier weather, with more intense rainfall and stronger winds would trigger faster erosion.

What risks does this present to individual food companies?

Soil erosion is a gradual process and is unlikely to cause any sudden shocks to the cost or availability of food. However, if erosion is not reversed at a global level, it would make the challenge of feeding a growing population increasingly difficult. Failure to keep pace with demand would cause world prices to spiral upwards and could eventually trigger trade embargoes and shortages.

Any companies using ingredients produced through deforestation face a growing reputational risk. Campaign groups are increasingly targeting this issue, even where companies have purchased the ingredients unaware of their origin.

What’s been the story so far?

Historically, a nomadic lifestyle allowed people to strip an area and move on. By the time they returned, the area could have recovered. Growing populations and the establishment of land rights made this increasingly unviable and it became necessary to manage land sustainably.

Civilisations that achieved this, prospered over time. Others declined and in some cases, disappeared.

As the demand for food expanded, farming spread to more marginal (less productive) land. The drive to increase yields in these areas has sometimes led to short-sighted, unsustainable practices.

Forests currently cover about 30% of the world’s land mass but according to the UN, around 18 million acres of forest land, equivalent to the size of Panama, is lost each year. About half of the world’s tropical forests have now been cleared.

The creation of a ‘dust bowl’ in the US Great Plains is another famous consequence of unsustainable farming. Although American farmers learnt from this, others have continued to make similar mistakes, over-ploughing, over-grazing and stripping away vegetation that acted as a windbreak.

Globally, more and more land is converting to desert and dust storms are becoming increasingly frequent, especially in China and Africa. According to the Earth Policy Institute, Nigeria, to give one example, is losing nearly 900,000 acres of farmland to desert each year. One estimate suggests that 25% of all land in India is in the process of converting to desert.

Although the UK does not suffer on that scale, high winds sometimes erode light soils in flat regions including the East Midlands, East Anglia and Vale of York. Flash floods also sometimes erode sandy and chalky soils.

What can companies do to reduce their own risks?

  • Recognise the risks in your supply chains at global and local levels and assess how they might impact on your company. Do this holistically, considering land use and soil degradation alongside other challenges including climate change and water shortages
  • Commit to sourcing products that do not involve deforestation (to reduce your reputational risk)
  • Use your influence to promote farming practices that conserve soil. In the UK, government advice can be found here: Advice on soil conservation
  • Good practices include ploughing across slopes, leaving stubble to protect ground from raindrop impact and applying organic fertilisers. An example of an integrated approach to both flooding and erosion on an arable UK farm can be found here: UK case study
  • Understand what others are doing to address land use and soil conservation
  • Identify if there are any collaborative programmes in the countries you purchase from that will help your business manage and mitigate risks

What can companies do to act responsibly?

  • Avoid sourcing products produced using unsustainable methods (and especially those that involve deforestation). Where this is not currently possible, develop a plan to source sustainably over time
  • Support research and trials in pursuit of “sustainable intensification” in farming (i.e. producing more from the same or less land with fewer inputs)
  • Promote market mechanisms that offer farmers worldwide enough security to think long term and invest in sustainable farming methods
  • Maintain an open and frank dialogue with all other stakeholders in agriculture and food production. Be transparent about your motives and policies
  • Join collaborative efforts in support of sustainable farming
  • Be cautious about investing in biofuels if this encourages converting land away from food production. Although the debate on biofuels is not entirely resolved, it is certainly contentious

Who has taken action?

  • Unilever, Pepsico, Kellogg and Arla Foods are among the 50+ members of the SAI Platform that seeks to develop sustainable agriculture practices globally, incorporating land use and soil conservation among other priorities

Where can you go for more information?

  • SAI Sustainable Agriculture Initiative
    Principles and practices for sustainable agriculture are presented in an authoritative and accessible way here
  • BCFN
    Sustainable agriculture and climate change presented with excellent graphical representation
  • FAO UN report on climate change
    Global perspectives on food security and climate change, incorporating the need for sustainable agriculture and food production, from UN Food & Agriculture Organisation

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