Mineral Fertilizer Use and the Environment International Fertilizer Industry Association United Nations Environment Programme

15.1. Resource availability
15.1.1. Energy
Fertilizers, especially nitrogen fertilizers, require
fossil fuel energy to manufacture, and some to
transport and apply. It is estimated that
worldwide agriculture uses about 5% of global
energy consumption. This includes nitrogen
fertilizer production, which is estimated to
account for less than 2% of annual world energy
consumption. This estimate of 5% excludes the
transport and processing of the agricultural
produce which is more energy intensive; for 1 kg
of bread, growing the wheat takes about 20% of
the energy used, while milling, baking and
distribution account for 80%. Thanks to
photosynthesis, in the case of cereals and root
crops the harvested energy is substantially greater
than the energy input. In the case of intensive
horticulture the energy input may be higher than
the energy output.
In France (Commissariat Général du Plan,
1997), in 1995 the manufacture of fertilizers
accounted for 1% of total energy consumption.
Agriculture, including the application of these
fertilizers, accounted for 1.6%. The food
processing industry, conservation and preparation
accounted for a further 8%.
The energy requirements for the manufacture
of fertilizers may be met by natural gas, oil,
naphtha or coal depending on the cost and
availability in the region of the world where the
ammonia is produced. In 1995 known coal
reserves amounted to about 450 years of 1995
production, natural gas 66 years and petroleum
43 years. Additional reserves tend to become
available as time passes, due to new discoveries
and/or technical progress. For example, in 1978
the US natural gas reserves:production ratio

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Mineral Fertilizer Use and the Environment
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Furthermore, substantial areas of good
agricultural land are being lost each year due to
urbanization and deterioration, the latter due, for
example, to salinity, erosion and desertification. It
is estimated that every year soil erosion and other
forms of land degradation rob the world of 5 to 7
million hectares of farming land (FAO, 1995).
Apart from areas of fertile land purposely
idled in the USA and West Europe, there are
some reserves of land which could be cultivated,