World agriculture towards 2030/2050: the 2012 revision - Fao

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Table 4.7 Land with rain-fed crop production potential by region (million ha)
Total
land
surface
Suitable
land*
Of which
Prime
land
Good
land
Of which in use as
(1999/2001)
Rainfed
land
Irrigated
land
Gross
balance
Not
usable**
Net
balance
World 13 295 4 495 1 315 3 180 1 063 197 3 236 1 824 1 412
Developing countries 7 487 2 893 816 2 077 565 138 2 190 1 227 963
Sub-Saharan Africa 2 281 1 073 287 787 180 3 890 438 451
Latin America 2 022 1 095 307 788 137 15 943 580 363
Near East / North
Africa 1 159 95 9 86 38 12 45 9 37
South Asia 411 195 78 117 85 55 55 43 11
East Asia 1 544 410 126 283 122 53 234 140 94
Other developing
countries 70 25 9 15 2 0 23 16 7
Developed countries 5 486 1 592 496 1 095 497 58 1 037 590 447
Rest of the world*** 322 11 3 8 2 0 8 7 1
Source: GAEZ-v3.0 in Fischer et al. (2011).
* Crops considered: cereals, roots and tubers, sugar crops, pulses and oil-bearing crops. Includes Very
Suitable, Suitable and Moderately Suitable land.
** Land under forest, built-up or strictly protected.
*** Countries not included in the regions above and not covered in this study.
Fourth, much of the remaining land suffers from constraints such as ecological fragility,
low fertility, toxicity, high incidence of disease or lack of infrastructure. These factors reduce
its productivity, and require high input use and management skills to permit its sustainable use
or prohibitively high investments to make it accessible or disease-free. Fischer et al. (2002)
show that more than 70 percent of the land with rainfed crop production potential in sub-
Saharan Africa and Latin America suffers from one or more soil and terrain constraints.
Natural causes and human intervention can also lead to deterioration of the land’s productive
potential, for example through soil nutrient mining, soil erosion or salinization of irrigated
areas. Hence the evaluation of suitability may contain elements of overestimation, and much
of the land balance cannot be considered as a resource that is readily useable for food
production on demand.
These considerations underline the need to interpret estimates of land balances with
caution when assessing land availability for agricultural use. Cohen (1995) summarizes and
evaluates all the estimates of available cultivable land, together with their underlying
methods, and shows their extremely wide range. Young (1999) offers a critique of the
estimates of available cultivable land, including those given in Alexandratos (1995), stating
that they often represent gross overestimates.
4.2.3 Expansion of land in crop production
Recently concerns have been voiced that agriculture might, in the not too distant future, no
longer be able to produce the food needed to sustain a still growing world population at levels
required to lead a healthy and active life. The continuing decline of arable land (in use) per
person (Figure 4.3) is often cited as an indicator of impending problems. The underlying
cause for such problems is perceived to be an ever increasing demand for agricultural
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