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sustainable food supplies
sustainable agriculture
Sustainable agriculture refers to the ability of a farmer to produce food indefinitely without causing irreversible damage to the local ecosystem. Two key issues in promoting sustainability are:
> biophysical - the long-term effects of various practices on the soil and other aspects of the environment
> socioeconomic - the long-term ability of farmers to obtain inputs and manage resources such as labour
> biophysical - the long-term effects of various practices on the soil and other aspects of the environment
> socioeconomic - the long-term ability of farmers to obtain inputs and manage resources such as labour
soil degradation
A number of practices can lead to irreversible soil degradation including excessive cultivation and over-irrigation leading to salt accumulations. Farmers remove nutrients from the soil when they grow crops and without replenishment the land would be unable to support agriculture. Sustainable practice replaces those nutrients while minimising the use of non-renewable resources and avoiding chemicals that could damage the environment. In sustainable farming, the nitrogen that farmers are seeking to replace can be obtained from:
> recycling crop waste
> using animal or human manure
> growing legume crops and forages such as peanuts and alfalfa which have bacteria in their roots that fix nitrogen in the soil
> recycling crop waste
> using animal or human manure
> growing legume crops and forages such as peanuts and alfalfa which have bacteria in their roots that fix nitrogen in the soil
causes of unsustainable agricultural practice
The Food and Agriculture Organisation of the United Nations (FAO) has identified five causes of unsustainable agricultural practice and degradation of the rural environment:
> policy failure - inadequate or inappropriate policies including pricing, subsidy and tax policies which have encouraged the excessive (and often uneconomic) use of inputs such as fertilisers and pesticides, and over-exploitation of land. Policies may also favour farming systems which are inappropriate to both the circumstances of the farming community and the available resources
> rural inequalities - rural people often know best how to conserve their environment, but they may need to over exploit resources in order to survive. Meanwhile, commercial exploitation by large landowners and companies often causes environmental degradation in pursuit of higher profits
> resource imbalance - almost all of the future growth in the world's population will be in developing countries and the biggest increases will be in the poorest countries of all - those least equipped to meet their own needs or invest in the future
> unsuitable technologies - new technologies have boosted agricultural production worldwide, but some have had harmful side effects which must be contained and reversed. Such side effects include resistance of insects to pesticides, land degradation through wind and water erosion, nutrient depletion or poor irrigation management, and the loss of biological diversity
> trade relations - as the value of raw materials exported by developing countries has fallen, their governments have sought to boost incomes by expanding crop production and timber sales, and this has damaged the environment
> policy failure - inadequate or inappropriate policies including pricing, subsidy and tax policies which have encouraged the excessive (and often uneconomic) use of inputs such as fertilisers and pesticides, and over-exploitation of land. Policies may also favour farming systems which are inappropriate to both the circumstances of the farming community and the available resources
> rural inequalities - rural people often know best how to conserve their environment, but they may need to over exploit resources in order to survive. Meanwhile, commercial exploitation by large landowners and companies often causes environmental degradation in pursuit of higher profits
> resource imbalance - almost all of the future growth in the world's population will be in developing countries and the biggest increases will be in the poorest countries of all - those least equipped to meet their own needs or invest in the future
> unsuitable technologies - new technologies have boosted agricultural production worldwide, but some have had harmful side effects which must be contained and reversed. Such side effects include resistance of insects to pesticides, land degradation through wind and water erosion, nutrient depletion or poor irrigation management, and the loss of biological diversity
> trade relations - as the value of raw materials exported by developing countries has fallen, their governments have sought to boost incomes by expanding crop production and timber sales, and this has damaged the environment
strategies for sustainable agriculture and rural development
The FAO suggests four strategies to obtain sustainable agriculture and rural development:
> intensification through specialism - cautious use of inputs such as pesticides and fertilisers combined with improved agricultural and related practices (soil management, integrated pest management, efficient waste management)
> intensification through diversification - minimising environmental and socioeconomic risks, assisting waste recycling and reducing the need for external inputs
> combining on-farm and off-farm activities - promoting additional sources of income can limit pressure on natural resources
> extensive systems - applicable to low population density areas where there is only light pressure on natural resources
> intensification through specialism - cautious use of inputs such as pesticides and fertilisers combined with improved agricultural and related practices (soil management, integrated pest management, efficient waste management)
> intensification through diversification - minimising environmental and socioeconomic risks, assisting waste recycling and reducing the need for external inputs
> combining on-farm and off-farm activities - promoting additional sources of income can limit pressure on natural resources
> extensive systems - applicable to low population density areas where there is only light pressure on natural resources