This document summarizes research on the relationship between agricultural intensification and land use change. It finds that increased crop yields have saved significant amounts of land from conversion globally since the 1960s due to Norman Borlaug's Green Revolution. However, yield increases can also increase profits and incentives to expand agricultural land in some contexts. While intensification is important to save forests, governance and sustainable practices are also needed to incentivize intensification over expansion of agricultural frontiers. Ongoing investment in agricultural research and development is critical but not sufficient to achieve land sparing and meet future global food and environmental goals.

1. Derek Byerlee,
James Stevenson (ISPC) &
Nelson Villoria (Purdue U)
The Land that Feeds Us:
Growing Land Scarcity and the
Borlaug Hypothesis Revisited
Borlaug 100
Ciudad Obregon
March 25-28th,
2014

2. 0
20
40
60
80
100
120
140
160
180
1961 1966 1971 1976 1981 1986 1991 1996 2001 2006
Index(1960=100)
Indices (1961 = 100)
Arable land per capita
2
Crop production per capita
Food prices
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
1961
1964
1967
1970
1973
1976
1979
1982
1985
1988
1991
1994
1997
2000
2003
2006
2009
2012
World cereal yields (t/ha)
more than doubled
Source: Calculated from FAOSTAT
Saved > 1 bill ha land
Borlaug, Science, 2007

3. WIKIPEDIA, 2014 ANGELSEN AND KAIMOWITZ, 2001
 “Borlaug continually
advocated increasing crop
yields as a means to curb
deforestation.The large role
he played in both increasing
crop yields and promoting
this view has led to this
methodology being called ..
the "Borlaug hypothesis”…..
 This section needs additional citations
for verification.Please help improve
this article by adding citations to
reliable sources (June 2011)
Agricultural Technologies and
Tropical Deforestation
Authors offer another view—
Increasing yields on the forest
frontier raises returns to land and
therefore incentives to expand
area (Jevon’s Paradox)

4. -1.00
0.00
1.00
2.00
3.00
4.00
5.00
OECD Transitional China South Asia SE Asia Brazil sub-Saharan
Africa
Growth%/yr)
Decomposition of Agricultural Growth, 1961-2009
TFP
Inputs
Irrigation
Land
Yield
Area
Source: Fuglie, Pers comm

5. BURNEY ET AL. (2010) PHELPS ET AL (2013)
 Increased global yields
since 1961 have saved 1.5 x
109 ha crop area.
 One third of saved land due
to cumulative investment of
$800 billion in R&D
 Investigates effects of
improved maize and cassava
techs on forests in DR Congo
 Conclusion: “The
relationship between
intensification and land
sparing for conservation in
tropical developing
countries is
dubious….intensification
may actually spur
agricultural expansion”

7. Crops
12%
Pastures
26%
Forest
31%
Other
31%
Global Land Use
(Cropland 1.5 bill ha)
 Since 1850 converted
to agriculture (Geist,
2001)
• 600 M ha forest
• 470 M ha savannah
 But since 1990, only
30 M ha increase
cropland (2%)
 2014—Push for SDG
of zero deforestation
by 2030

8. 0 20 40
Sugararcane
Oil Palm
Rice
Maize
Soybean
M ha per year
By crop, 1990-2007 FAO: Cropland in
tropical countries
expanded 100 M ha
1990-2010
• Largely in L. America,
SE Asia and SS Africa
 Satellite: 1980-2000,
tropical agriculture
expanded 75 M ha,
with 75% of that from
forests (Gibbs et al., 2010)

9. Low estimate High estimate
M ha M ha
Additional land for:
Crops other than biofuels 81 147
Biofuels 44 118
Plantation forestry 56 109
Grazing 0 151
Total 181 374
Land lost to:
Cities and infrastructure 48 100
Degradation 30 87
Protected areas 26 80
Total (gross) 207 454
Source: Lambin et al, 2011. PNAS

10. 0
100
200
300
400
500
600
700
SS Africa Latin America E. Europe &
CA
E and S Asia MENA Australia Rest of world
Millionha
Potential additional area
Current area 2005
Brazil,
Argen
Sudan,
Congo, ,
Mozam
Madag,
Zambia
Russia
Australia
Based on land that is not forested
or protected and pop dens < 25/km
Total of 450 M ha (≈ demand (high))
(Wheat 75 Mha)
Source: Deininger and Byerlee (2011) based on IIASA-GAEZ

11. WIKI-ESTIMATES, 2000-13 SS AFRICA—18 M HA 2005-11
Food
25%
Biofuels
43%
Integrate
d
food/fuel
20%
Wood
& fibre
10%
Other
2%
Source: Schoneveld, 2014
0
0.5
1
1.5
2
2.5
3
3.5
4
Other
Total: 955 agric projects, 35 M ha
(excludes high income countries)
Source: Landmatrix.org

12. EXPONENTIAL EXPANSION RIAU, INDONESIA, 1982-2007
 Area doubled every
decade from 1970
 Investment of $50+ billion
since 2001
 Often high social and
environmental costs
• Much of it on previously
forested land in SE Asia

14. Intens.
on the
frontier
Increased
profits
Higher
returns
to land
Intens.
away
from
frontier
Increase
demand
for labor
Migration
frontier to
intensifyi
ng area
Broad-
based
intens.
Reduced
output
prices
Decrease
returns to
land
Pathways from intensification
to land use
Pressure to expand
land area
Trade

15.  18 global AEZs based on spatially-explicit datasets on yield and
land use:
Counterfactual:
A world without CGIAR
crop germplasm
improvement since
1965
Source: Stevenson, Byerlee,
Villoria et al., PNAS, 2013

16. Cropland Pastures Forests
Developing
countries
1.52 − 0.66 − 0.66
Developed
countries
0.87 − 0.36 − 0.51
• Overall estimate that agricultural area in 2004 would have
increased by 18 – 27 M ha mostly in developing countries
•
•[Dwarfed by effects of lower food price on human welfare]
Source: Stevenson, Byerlee,
Villoria et al., PNAS, 2013

17. Scenario 1: Close yield gap in oil palm by 35% in SE Asia over 25 yrs
Note; Does not include value of biodiversity
Source: Villoria, Byerlee & Stevenson., 2013
SE Asia
Land use and emissions SE Asia; Scenario 1
Global

18. Global R&D
Investments
(S2)
Investments
R&D
In Africa and
Latin Am. only
(S3)
Source: Lobell et al, 2013
Conclusion: Investing in R&D for broad adaptation to
CC is a cost effective way to save forests and mitigate
climate change.
• Still projects 250 Mha area increase by 2030
with perfect adaptation.
Scenarios
S1.No adaptation
S2. R&D to adapt
(yields unaffected by CC)
S3. Adaptation only in
LA and Africa
95% confidence
intervals

19.  New market
opportunities through
trade
Oil palm in SE Asia
Little technical change after
1980
• Soybean in Latin
America
 Markets + Technology
0
10
20
30
40
50
60
70
80
90
100
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
Soybean imports (Mt)
China
World
China
World

20.  Sustainable
intensification
through higher input
efficiency and
improved NRM
• Reduce agro-chemical
externalities
• See Fischer, Byerlee &
Edmeades (2014),
Chapter 8
 Landscape
approaches that
preserve mosaics
• Debate on land
sparing
(specialization) vs
land sharing (bio-
diverse mosaics)

21.  Broadly-based investment in crop R&D one of the
best ways to save forests globally (as Borlaug
claimed)
 Net global saving in land from intensification
often co-exists with forests losses at local level
 Improved governance of forests critical to
provide incentives to intensify vs expand area
Regulation, incentives (private certification, REDD)
Brazil vs Indonesia, 2005-2012
 SDG of zero deforestation in 2030 requires
accelerated efforts on yields plus governance

22. References
Stevenson,Villoria, Byerlee, PNAS 110: 8363-68, 2013
Villoria, Golub, Byerlee & Stevenson, Am. J. Ag. Econ,
95:1308-13
 Villoria, Byerlee & Stevenson, App. Econ. Pers &
Policies (in press)
Byerlee,Villoria and Stevenson, Global Food Security
(in review)
Additional information
dbyerlee@gmail.com