Discount mulberry bag for sale Outlet carbon storage capacity investigated
As atmospheric CO2 levels rise, methods to mitigate these increases are becoming very important. Three studies published in the July August 2008 issue of Soil Science Society of America Journal explore the potential roles of soils as a C sink in different regions in the Western Hemisphere. Scientists from Alberta Agriculture and Rural Development (Canada), the National Institute of Agricultural Technology, the University of Buenos Aires (Argentina), and University of California, Davis (USA) have investigated soil C balance in distinct agroecosystems under different management practices including soil tillage, N fertilization, elimination of fallow, and establishment of grass. In each case, C sequestration occurred in response to higher C input to soil; however, increase in SOC was confined to labile fractions such as the light fraction and larger soil aggregates. Investigation: Canada
In southeastern Alberta, a long term study showed previously that eliminating summer fallow or establishing grass significantly increased soil organic C after 6 yr. In the 12th year of the study, total organic C and light fraction C were determined in three rotations with summer fallow, two continuously cropped rotations and grass. All rotations had subtreatments with different levels of fertilization. The light fraction of soil C was obtained using density separation and consisted mostly of non decomposed root and straw fragments.
Although soil organic C was increased by elimination of summer fallow, fertilization, and establishment of grass,
gains in soil organic C between Years 6 and 12 were negligible in all treatments except the fertilized grass treatment. Most of the gains in total soil organic C were due to increased light fraction C. The results indicate that much of the gain in soil organic C in response to improved practices on semiarid prairie soils likely occurs within one decade.
The full article is available for no charge for 30 days following the date of this summary. Emissions of CO2 C from the soil and crop C inputs were determined, estimating soil C balance under both tillage systems.
As a part of this study, a field experiment was performed during 6 yr on an Entic Haplustoll where no till and disk tillage was applied to a soil cropped under a common rotation in the region (oat + hairy vetch, corn, wheat, oat). From Year 3 to 6 in situ CO2 C fluxes were measured and C inputs from above and below ground plant residues were estimated.
Results showed that in the semiarid environment of the study C sequestration occurred under no till. The sequestration process was attributed to the effect of tillage systems on crop productivity rather than on the mineralization intensity of soil organic pools.
The full article is available for no charge for 30 days following the date of this summary. In this experiment, a gradient of soil C input was produced with four N fertilizer application rates under two tillage systems, no till and moldboard plowing. To investigate if physical protection of organic C leads to soil C saturation, C stabilization in soil fractions that differ in C stabilization potential was determined, and the relationship between soil C input and soil organic C was analyzed.
Total soil organic C was positively related to C input, and this was primarily due to C stabilization in larger soil aggregates. In both tillage systems, however, C in the two smallest soil size fractions did not increase with greater C input. Moreover, in three soil fractions further separated from larger soil aggregates, C associated with particulate organic matter and microaggregates increased with C input, but there was no increase in C associated with silt plus clay, which was the smallest soil size fraction. Therefore,
we need to consider soil C saturation levels to better predict the change in C sink capacity and fertility of soils when soil C input increases under higher plant production or organic amendment.”
SharePrint this ArticleLearn more aboutalberta agriculture and rural development buenos aires argentina carbon storage soil aggregates soil science society of america journal storage capacity.