What
is carbon sequestering and how could it mitigate climate change?
Crops and other plants remove CO2 from the
atmosphere and, as they are harvested, their residue and roots are deposited
into the soil where portions can remain for long periods as soil organic
matter.
This process is
known as carbon sequestration, plants
and soils act as “sinks” for atmospheric carbon dioxide. Carbon “sequestered”
in vegetation and soil is captured in the sink, providing a significant boost
in the efforts to reduce greenhouse gases.
Carbon accumulation in agricultural soils can be greatly
improved by various forms of conservation management, such as no‑till and
replanting with grasses. This carbon sequestration occurs because there
is less soil disturbance and more carbon is added to the soil. Benefits
of carbon sequestration are increased soil fertility, reduced soil erosion and
increased soil quality.
What is
the largest source of carbon dioxide emissions in agriculture?
The single main source of greenhouse
gases in agriculture is from fertilizers:
the production of fertilizer is an energy intensive process which uses fossil
fuels as raw materials (mostly methane). When fertilizer is applied to the land
it emits more nitrous oxide emissions. This results in the emission of large
quantities of carbon dioxide and nitrous oxide.
Fertilizers also acidify the soil,
requiring the regular application of lime by farmers, in turn that process,
produces more carbon dioxide. Fertilizers also have the effect of suppressing the soil micro-organisms
that break down methane in the atmosphere. By reducing the soil oxidation
rates, fertilizers cause there to be more methane in the atmosphere.
What is
No-till farming?
Also known
as conservation tillage or zero tillage, it is a way of growing
crops from year to year without disturbing the soil through tillage.
Converting
from conventional plow tillage to no-till practices is among the most
cost-effective ways to reduce the buildup of carbon dioxide in the atmosphere. No-till
also increases the accumulation of soil organic carbon, thereby resulting in
sequestration of atmospheric carbon dioxide.
Changing tillage practices can:
- Reduce the need for fertilizer.
- Decrease emissions of oxides of nitrogen by applying nitrogen fertilizers only when and in quantities needed.
- Decrease the costs of chemical and mechanical treatments of crops and the labor they require.
- Reduce field activity with equipment, thereby reducing farm machinery emissions from fossil fuels.
What are
some of the possible positive effects on agricultural that could result from climate
change?
- Longer growing season due to higher average temperatures (more frost free days.)
- Opportunity for growing longer season, diversified crops, i.e. cover crops, winter wheat, corn, switch grass.
- More diversity in crop rotations, will give more options for disease, insect, weed controls.
- Shorter and milder winters (may lower heating requirements, reduce winter feeding, easier winter grazing, less winter kill and risk to crops).
What
are some of the potential agricultural risks that might be associated with
Climate Change?
- Increased occurrences of extreme weather drought, flooding, heat waves, etc.
- Decreased soil moisture and water shortage and availability.
- Water will become more valuable, irrigation will become more costly.
- Accelerated wet and dry summer cycles from more extreme weather events.
- Input costs could increase, increased energy, higher fertilizer and chemical prices
- Extreme weather events may increase the risk of soil erosion and crop damage.
- Increased occurrence of forest fire and possibly grass fires.
- Increased pest infestations due to milder winters and longer growing seasons (which may
increase the need for pesticides).
- Crop price increases due to shortages and competition (market demand) for climate - policy driven biofuel initiatives, animal feed costs may also increase.
How
can organic agriculture effect climate change?
Rodale study; Organic Farming
Sequesters Atmospheric Carbon and Nutrients in Soils
"Organic farming may be one of the most powerful tools in the fight against
global warming." Findings from The Rodale Institute’s 23-year Farming Systems
Trial® (FST) comparing organic and conventional cropping systems show
organic/regenerative agriculture systems reduce carbon dioxide, a major
greenhouse gases-positioning organic farming as a major player in efforts to
slow climate change.
Besides being a significant underutilized carbon sink, organic systems use
about one third less fossil fuel energy than that used in the conventional
corn/soybean cropping systems. According to studies of the FST in collaboration
with Dr. David Pimentel of Cornell University, this translates to less
greenhouse gases emissions as farmers shift to organic production. The ability
of organic agriculture to be both a significant carbon sink and to be less
dependent on fossil fuel inputs has long-term implications for global
agriculture and its role in air quality policies and programs.
The Rodale Institute’s 23-year findings show that organic grain production
systems increase soil carbon 15 to 28%. Moreover, soil nitrogen in the organic
systems increased 8 to 15%. The conventional system showed no significant
increases in either soil carbon or nitrogen in the same time period. Soil
carbon and nitrogen are major determinants of soil productivity.
Increasing soil organic matter for the soil’s carbon bank is a principle goal
of organic agriculture. Organic agriculture relies on the carbon bank and
stimulated soil microbial communities to increase soil fertility, improve plant
health, and support competitive crop yields. This approach utilizes the natural
carbon cycle to reduce the use of purchased synthetic inputs, increase energy
resource efficiency, improve economic returns for farmers, and reduce toxic
effects of fertilizers and pesticides on human health and the environment.
Organic farming can
play a major role in addressing climate change.
“Organic agriculture’s use of compost and crop
diversity means it will also be able to better withstand the higher
temperatures and more variable rainfall expected with global warming. Organic
agriculture is about optimizing yields under all conditions,” says Louise
Luttikholt, strategic relations manager at the International Federation of Organic Agriculture (IFOAM) in Bonn, Germany. IFOAM is the
international umbrella organization of organic agriculture movements around the
world.” For example, a village in the Tigray region of northern Ethiopia that
had converted to organic agriculture continued to harvest crops even during a
severe drought, while neighboring villages using conventional chemical fertilizers
had nothing, Luttikholt told IPS. Because compost is used rather than chemical fertilizers,
organic soils contain much more humus and organic carbon — which in turn
retains much more water. They can also absorb more water faster which means
they are less likely to flood,” she said
Resources;
USDA;
http://www.nrcs.usda.gov/Technical/land/pubs/ib3text.html
FAO;
http://www.fao.org/DOCREP/005/Y4137E/y4137e02b.htm
Rodale; http://www.strauscom.com/rodale-release/
Rodale; http://www.strauscom.com/rodale-whitepaper/
Soil Association; www.soilassociation.org
TOYAKO – [08.07.08] Heat resistant
PLA fabrics and recycled polyester textiles from Teijin Fibers have featured at
an eco fashion show as part of the G8 Hokkaido Toyako Summit of world leaders
currently taking place in Japan. 
