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ARS Home » Pacific West Area » Kimberly, Idaho » Northwest Irrigation and Soils Research » Research » Publications at this Location » Publication #183679
Title: CARBON SEQUESTRATION IN IRRIGATED PASTURES

Author
item SHEWMAKER, GLENN - UNIVERSITY OF IDAHO
item Entry, James
item Sojka, Robert

Submitted to: Grassland International Congress Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 1/1/2005
Publication Date: 7/1/2005
Citation: Shewmaker, G.E., Entry, J.A., Sojka, R.E. 2005. Carbon sequestration in irrigated pastures. In: O'Mara, F.P., et al. (editors). Grassland International Congress Proceedings, June 26-July 1, 2005, Dublin, Ireland. p. 594.

Interpretive Summary: Carbon sequestration potential for irrigated grazing lands is significant. We measured organic and inorganic carbon stored in southern Idaho soils having long-term land use histories that supported native sagebrush vegetation (NSB), irrigated pasture systems (IP), irrigated conservation tillage sites (ICT), and irrigated moldboard plowing systems (IMP). This study estimates the amount of possible organic, inorganic and total carbon sequestration if irrigated pasture land was expanded by 10%. Inorganic carbon and total carbon (inorganic + organic carbon ) in soil were higher in IP than NSB. If irrigated pasture land was expanded by 10%, meaning NSB land was converted to IP, a possible gain of 1.7 % of the total carbon emitted in the next 30 year could be sequestered in soils worldwide. If irrigated agricultural land was expanded worldwide and NSB was converted to IP, while an equal amount of less-productive rainfed agricultural land was returned to native grassland, a possible gain of 11.9 % of the total carbon emitted in the next 30 yr could be sequestered in soils. The expansion of irrigated pasture land would significantly increase carbon sequestration in soils world-wide. Land use shift from relatively low productivity rainfed agricultural land to temperate forest or native grassland could also cause meaningful reductions in atmospheric carbon dioxide.

Technical Abstract: Carbon sequestration potential for irrigated grazing lands is significant. We measured organic and inorganic carbon stored in southern Idaho soils having long-term land use histories that supported native sagebrush vegetation (NSB), irrigated pasture systems (IP), irrigated conservation tillage sites (ICT), and irrigated moldboard plowing systems (IMP). This study estimates the amount of possible organic, inorganic and total carbon sequestration if irrigated pasture land was expanded by 10%. Inorganic carbon and total carbon (inorganic + organic carbon ) in soil were higher in IP than NSB. If irrigated pasture land was expanded by 10%, meaning NSB land was converted to IP, a possible gain of 1.7 % of the total carbon emitted in the next 30 year could be sequestered in soils worldwide. If irrigated agricultural land was expanded worldwide and NSB was converted to IP, while an equal amount of less-productive rainfed agricultural land was returned to native grassland, a possible gain of 11.9 % of the total carbon emitted in the next 30 yr could be sequestered in soils. The expansion of irrigated pasture land would significantly increase carbon sequestration in soils world-wide. Land use shift from relatively low productivity rainfed agricultural land to temperate forest or native grassland could also cause meaningful reductions in atmospheric carbon dioxide.