Challenges of Agriculture 35701020304050607080901001980
Year2005Developed countries
Developing countries
WorldPer-capita meat consumption(kg per person per year)Based on data from FAO,The State of Food and Agriculture2009,Table 1, p.11 (2009).and corn will certainly increase in the coming years. This
rise in demand will require a corresponding rise in grain
production to feed the human population, as well as the
livestock needed to satisfy the appetites of the increasing
numbers of affluent people who can afford to buy meat
(Figure 14.9). Also, the increased use of crop plants to
produce biofuels, such as ethyl alcohol, rather than food
will increase global demand.
This challenge cannot be met by increasing the
amount of land under cultivation, as the best arable
lands are already being cultivated. Projected freshwa-
ter shortages, rising costs of agricultural chemicals, and
deteriorating soil quality caused by intensive agricul-
tural techniques may further constrain productivity. As
Figure 14.8 demonstrates, recent progress in coaxing
more grain out of crops genetically improved during the
green revolution has resulted in diminishing returns.
Grain yields have continued to rise since the 1960s, but in
recent years the rates of increase have not been as great
as they were previously.
Despite these problems, most plant geneticists think
we can produce enough food in the 21st century to meet
demand if countries spend more money in support of
a concerted scientific effort to improve crops. Many sci-
entists regard genetic engineering as one of the keys to
breeding more productive varieties. In addition, modern
agricultural methods, such as water-efficient irrigation,
will need to be introduced to developing countries that
do not currently have them if crop yields are to continue
increasing.less than 0.7 metric tons (0.8 ton) of wheat per hectare
annually. During the green revolution years that began
in 1965, Mexico’s annual wheat production rose to
more than 2.4 metric tons (2.7 tons) per hectare. Indo-
nesia, another green revolution success story, formerly
imported more rice than any other country in the world.
Today Indonesia produces enough rice to feed its people
and export some. The outcome of the green revolution
was not just greater food production: Now that develop-
ing countries produced enough food, they could focus
more on economic development.
Critics argue that the green revolution has made
developing countries dependent on imported technolo-
gies, such as agrochemicals and tractors, at the expense
of traditional agriculture. The two most important prob-
lems associated with higher crop production are the high
energy costs built into this type of agriculture and the
serious environmental problems caused by the intensive
use of fertilizers and pesticides.Increasing Crop Yields in the Post–Green
Revolution Era The world demand for rice, wheat,Development of high-yield rice varieties
UÊ}ÕÀiÊ£{°nÊTall conventional plant Improved high-yielding
plant
Newer plant with
fewer leavesTraditional rice plants on the left are taller and do not yield
as much grain (clusters at top of plant) as the more modern
varieties shown in the middle and on the right. The rice plant in
the middle was developed during the 1960s by crossing a high-
yield, disease-resistant variety with a dwarf variety to prevent
the grain-heavy plants from falling over. Improvements since the
green revolution have been modest, as shown in the rice variety
developed during the 1990s (right). Some researchers think
rice and certain other genetically improved crops are near their
physical limits of productivity.Increased meat consumption, 1980–2005
UÊ}ÕÀiÊ£{°Ê