Chemistry Reference
In-Depth Information
d
n
1
r
2
n
g
|
3
Figure 4
Nutrient balances for N, P and K for Africa.
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phosphate rock by 30-50%, depending on grade. In contrast, mined potash
production would need to more than double to balance current agricultural
requirements as expressed in terms of nutrient outputs.
4 Projections of Need to Support a Growing World
Population
The nutrient audits carried out for 1996 correspond to a world population of
5.8 billion. In 2011, the world's population reached 7 billion, and is project to
rise to 9 billion in 2050. In Africa, the current population is approximately 1
billion, and this will double by 2050. Food security is a major concern.
15,18
Nutrient audits show that world production of fertilisers is insufficient to
meet the needs of current populations. Simply on the basis of projected growth
in numbers, the present deficit will only get worse; projected deficits are
summarised in Table 4. This means that the world's arable soils will continue
