Agriculture Reference
In-Depth Information
9.5
IMPACT OF LAND DEGRADATION ON FOOD SECURITY
9.5.1 r eLatIonShIp of L and d egradatIon and c rop y IeLd g ap
As noted earlier, land degradation has contributed to increasing the number of hun-
gry people. Rough estimates by the World Bank show that between 2000 and 2010,
land degradation contributed about 20% of the hungry people in SSA (Word Bank
Development Indicators 2010). Land degradation has been one of the factors that
have led to lower agricultural productivity in SSA and other regions with severe
land degradation. This has contributed to wider yield gaps in SSA, South Asia, and
Central Asia—regions that experienced land degradation between 1981 and 2003
(Figure 9.5). Many studies have shown that sustainably increasing agricultural pro-
ductivity on the existing agricultural land—rather than converting forests and other
nonagricultural lands to agriculture—is the most feasible solution to addressing the
increasing population and its need for additional crop resources, as well as losses of
biodiversity and other such challenges (Rockstrom et al. 2009). With a slowing rate
of increase in crop yields arising from narrowing gaps between potential and actual
yields in much of the developed regions and East Asian countries (Bruinsma 2009),
meeting the increase in food demand through yield increases means directing global
and national efforts in regions where there is a wide yield gap. Recent simulation
scenarios have shown that increases in land productivity will have to account for
77% of the expected growth in global food demand by 2050—demand that is stem-
ming from a growing population and changing dietary preferences (Bruinsma 2009).
70%
60%
50%
40%
30%
20%
10%
0%
East
Asia
North
America
South
Asia
We stern
Europe
EECA
LACMENA
SEAO
SSA
World
Maize
Rice
Wheat
46%
19%
34%
61%
61%
56%
41%
34%
35%
40%
25%
46%
15%
12%
39%
25%
34%
41%
51%
40%
49%
63%
65%
52%
3%
24%
12%
39%
32%
42%
Key:
EECA = East Europe and Central Asia; LAC = Latin America and Caribbean Countries;
MENA = Middle East and North Africa; SEAO = Southeast Asia and Oceania;
SSA = Sub-Saharan Africa
FIGURE 9.5 Yield gaps of maize, rice, and wheat across regions. (From Licker, R. et al.,
Global Ecol Biogeogr 119(6):769 -782 , 2010.)
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