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148 Ökobilanz von Danone Activia-Verpackungen 2011 IFEU Heidelberg
Anhang III. Soil Carbon sequestration during corn production
Autor: E. Vink, NatureWorks LLC, February 05 2006
Globally, agriculture in the U.S. contributes about 2 percent of the gases that lead to
the greenhouse effect. In the US, agriculture contributes about 10% of the total
human-caused greenhouse gases (DOE 1999 and Snyder and Bruulsema 2002).
“Agricultural intensification through adoption of scientifically proven best management
practices (BMP) can solve, rather than cause, numerous environmental problems,
including CO2 emission. BMPs can improve soil organic carbon (SOC) content,
enhance soil quality, restore degraded ecosystems, increase biomass production,
improve crop yield, and encourage investment in soil resources for soil restoration.”
(Lal 1998)
Robertson (Robertson 2000) studied the influence of tillage practices on the
emissions of greenhouse gases. During the period of 1991-1999 N2O production,
CH4 oxidation and soil carbon sequestration were studied in a replicated series of
cropped and unmanaged ecosystems in the Midwest United States. Among others,
four corn-wheat-soybean rotations were studied under the assumption that these
plantings were managed with: (I) conventional chemical inputs and tillage, (II)
conventional inputs and no tillage, (III) reduced chemical inputs, and (IV) organically
with no chemical inputs. The latter one did not include manure applications, as is
often the case in organic systems. Manure amendments can greatly increase the
emissions of greenhouse gases (Snyder and Bruulsema 2002). The latter two
treatments included a winter legume cover crop following the corn and wheat portions
of the rotations to provide nitrogen and mechanical cultivation to control weeds. In
both cases the cover corps were plowed back into the soil. The results are
summarized in Table 1.
Endbericht – Bearbeitungsstand 29. März 2011