Management of irrigated agriculture to increase organic carbon storage in soils

Entry, J.A. and Sojka, R.E. and Shewmaker, G.E. (2007) Management of irrigated agriculture to increase organic carbon storage in soils. In: Plattenberg, R.H., (ed.) Environmental Pollution: New Research. pp. 121-139. Nova Science Publishers, New York, NY.

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Abstract

Increasing the amount of C in soils may be one method to reduce the concentration of
C02 in the atmosphere. We measured organic C stored in southern Idaho soils having long
term cropping histories that supported native sagebrush vegetation (N SB), irrigated moldboard
plowed crops (IMP), irrigated conservation -chisel- tilled crops (ICT) and irrigated pasture
systems (1?). The C02 emitted as a result of fertilizer production, farm operations and CO;
lost via dissolved carbonate in irrigation water, over a 30 year period, was included. Net
organic C in ecosystems decreased in the order IP>ICT>NSB>IMP. In this study, if NSB were
converted to IMP, 0.15 g C m“2 would be emitted to the atmosphere, but if converted to IP
, 3.56 g C m'2 could be sequestered. If IMP land were converted to ICT, 0.95 g C m"2 could be
i sequestered in soil and if converted to I? 3.71 g C 111'2 could be sequestered. There are 2.6)(108
ha of land worldwide presently irrigated. If irrigated agriculture were expanded 10% and the
same amount of rainfed land were converted back to native grassland, an increase of 3.4x109
Mg C (5.9% of the total C emitted in the next 30 yr) could potentially be sequestered. The
total projected release of CO2 is 5.7x10‘° Mg C worldwide during the next 30 years.
Converting rainfed agriculture back to native vegetation while modestly increasing areas in
f irrigated agriculture could have a significant impact on C0; atmospheric concentrations while
maintaining or increasing food production.

Item Type:	Book Section
NWISRL Publication Number:	1232
Subjects:	Soil > Chemistry Mass Import - autoclassified (may be erroneous)
Depositing User:	Dan Stieneke
Date Deposited:	20 Nov 2010 21:55
Last Modified:	31 Oct 2016 16:52
Item ID:	833
URI:	https://eprints.nwisrl.ars.usda.gov/id/eprint/833