Climate Change and CIMMYT

JIRCAS International Symposium Proceedings

Climate change?including higher average temperatures, heightened extremes in weather, and
increased atmospheric carbon dioxide levels?is expected to impact most severely upon agriculture in
the developing world. Research on major maize and wheat production areas in key parts of the
developing world suggest that changes in temperature, growing season length, and rainfall patterns
will significantly reduce crop yields, challenging farmers’ ability to make a living and affecting
regional food security and livelihoods. Expected changes may also include reduced grain quality,
intensified nitrogen leaching and soil erosion, and shrinking land and water resources for farming.
CIMMYT is working with partners worldwide to mitigate these and other effects of climate change on
the poor in developing countries. The efforts will help maize and wheat farmers to increase
productivity using tomorrow’s limited land and water resources and to deal with environmental and
market instabilities.
Stress tolerant crop cultivars. Improved maize cultivars that tolerate drought, heat, and low soil
fertility will help maize farmers in stress-prone areas to obtain better harvests under dry conditions and
higher temperatures. In Southern Africa alone, enough seed of new, stress tolerant cultivars has been
produced to sow two million hectares. The work has received added impetus recently and is being
extended to Asia and Latin America. The Center has also developed wheat lines that are better at using
available water to produce grain. Experimental cultivars derived from crosses between wheat and goat
grass, one of wheat’s wild relatives, produced up to 30% more grain than their wheat parents, in tests
over two years under tough dryland conditions. In more recent experiments, this type of wheat out
yielded its pure wheat parents by 18% under irrigation and drought, due in part to an increased ability
to take up water from greater depths, superior water use efficiency, and, possibly, improved early vigor
that increases ground cover and thereby conserves soil moisture. These wheat cultivars can help
farmers in irrigated areas, where water is growing scarce, as well as resource poor farmers who grow
the crop under rainfed conditions for food, income, and livestock fodder. They are being used in
breeding programs worldwide, and their derivatives are being released to farmers in China and
highland Ecuador. CIMMYT scientists are also seeking and testing new sources of drought tolerance
from gene bank collections and other wheat or grass species, including wheat landraces brought to
Mexico by Spanish colonizers and grown for centuries under dry conditions. Likewise, CIMMYT
breeders have worked for nearly two decades to develop heat tolerant wheat. They have identified key
physiological traits associated with higher yields in heatstressed environments, including low canopy
temperatures and high leaf chlorophyll content during grain filling. Partly as a result of the
development and release of improved, stress tolerant cultivars by CIMMYT and partners, wheat yields
improved 2 to 3% per year in dry and heat stressed environments in developing countries from 1979 to
Saving soil, water, money. Fundamental changes in farming practices will be central to getting maximum
benefits from improved maize and wheat and to addressing and mitigating climate change. CIMMYT has
studied and fostered testing and adoption by farmers of various resource-conserving practices?including
conservation tillage and keeping a crop residue cover on the soil?to save food production costs and
resources, and maintain or improve soil quality. The Rice-Wheat Consortium (RWC) for the Indo-Gangetic
Plains, an award-winning national agricultural research systems-led eco-regional partnership, has fostered
the adoption of conservation tillage to sow wheat after rice by farmers on nearly 2 million hectares in South
Asia. The practice results in a net savings of 50 liters or more of diesel per hectare, greatly reduced water
use, and lower CO2 emissions. These and other practices being tested by farmers (for example, sowing on
permanent, raised beds) provide a better soil cover, moderate soil temperatures, and reduce the evaporation
of irrigation water. Fertilizer is another resource whose efficient use can improve crop productivity and reduce greenhouse gas emissions and other damage to the environment. With the Center’s help, wheat
farmers in irrigated zones of Latin America and South Asia are testing use of infrared sensors to fine-tune
fertilizer amounts, timing, and application methods. This saves money for farmers and cuts emissions of
nitrous oxide, a gas with some 300 times the greenhouse effects of carbon dioxide. Research to date also
supports the hope of using wheat’s grassy relatives as a source of genes to inhibit soil nitrification and the
associated release of nitrous oxide.
Socioeconomic research, knowledge-sharing. Resource efficient crop cultivars and
knowledge-intensive, conservation agriculture farming practices must be properly tested by scientists and
with farmers. Participatory and socioeconomic research by CIMMYT supports such efforts, as in the case
of the RWC or work on stress tolerant maize for sub-Saharan Africa. It also elucidates economic and policy
issues relating to climate change and developing world agriculture. For example, a recently-completed
series of studies on maize production in marginal areas of seven Asian nations is serving as a baseline
against which to gauge changes and devise interventions. Addressing new climate conditions will require
complex policies and adjustments at many levels in developing country agriculture. Many players in maize
and wheat market chains could benefit from reliable information on the economic opportunities and risks
associated with biofuel expansion. Socioeconomics knowledge will help guide the use of Center resources
best to catalyze relevant change among a wide range of stakeholders and partners. CIMMYT can develop
and share information dissemination products/systems about climate change for farmers, policy makers,
and others in agricultural market chains. This will be crucial, given that farmers will need to apply
knowledge-intensive practices such as increased cropping diversification, use of rotations to manage pests
and pathogens, and generally more robust systems that provide insurance against risks and shocks from
climate extremes.
Information technology and monitoring systems. Building on linkages within the center’s global
maize and wheat nursery systems and geographic information system capacity and partnerships, it will be
possible to form networks that allow researchers to follow and anticipate the movement of pathogens, pests,
and invasive species and share the information with relevant stakeholders. For example, CIMMYT
characterizations of heat-stressed wheat environments are being refined using spatial analysis and climatic
factors identified through multi-location trials in those environments.
No security without food security. It is already clear that the security and quality of life of affluent
nations are closely tied to conditions and events in the developing world. A 2007 report by the German
Advisory Council on Climate Change, states that “…without resolute counteraction, climate change…
could result in destabilization and violence, jeopardizing national and international security to a new
degree.” Falling agricultural yields would block development and heighten poverty, thereby increasing the
risk of conflicts. Decades prior to that report, CIMMYT wheat breeder and 1970 Nobel Peace Laureate,
Norman Borlaug, said roughly the same thing in these terms: “If you desire peace, cultivate justice, but at
the same time cultivate the fields to produce more bread; otherwise there will be no peace.” Now and in
the future, CIMMYT contributes to global security and peace by improving the food security and
livelihoods of those who depend on maize and wheat farming in developing countries.

作成者 Rodomiro Ortiz

Conservation agriculture



plant breeding

公開者 Japan International Research Center for Agricultural Sciences
開始ページ 119
終了ページ 127
権利 Japan International Research Center for Agricultural Sciences
言語 eng