Submitted to: Environment Control in Biology
Publication Type: Peer reviewed journal
Publication Acceptance Date: 5/6/2005
Publication Date: 9/1/2005
Citation: Prior, S.A., Runion, G.B., Rogers Jr, H.H., Conn, J.S., Cochran, V.L. Atmospheric co2 enrichment of potato in the subarctic: root distribution and soil biology. Environmental Control in Biology. 43(3):165-172. Interpretive Summary: The increasing level of CO2 in the atmosphere has led to concerns on how this may impact various cropping systems. Our goal was to determine how elevated CO2 would affect potato roots and organisms that live in the soil under the subarctic environment of Fairbanks, Alaska. This region represents the northern limit of commercial agriculture in North America. We found that elevated CO2 had no affect on potato roots or the activity organisms in the soil. Thus, our results suggests that changes in atmospheric CO2 level are unlikely to alter these belowground responses in subarctic potato production systems of Alaska.
Technical Abstract: The effect of increasing atmospheric CO2 concentration on fine root distribution of potatoes and associated soil biology activity under subarctic conditions has not been studied. Potato plants (Solanum tuberosum L.) were grown in open top field chambers at three CO2 concentrations [ambient (A); A + 175 µmol mol-1 CO2 (A+175); A + 350 µmol mol-1 CO2 (A+350)] and in ambient CO2 plots with no chambers (ANC) on a Tanana silt loam (non-acid loamy, mixed Pergelic Cryaquept) at Fairbanks, AK in 1994. Soil cores to a depth of 60 cm were taken at 0, 19, and 38 cm perpendicular to row center; root variables were ascertained at four 15 cm depth increments. Soil cores to a depth of 15 cm were also collected to assess soil biology (dehydrogenase activity, nematodes, and soil microarthropods). Elevated CO2 did not enhance root densities (i.e., both length and mass) at any depth or row position; there was no significant CO2 X depth, CO2 X position, or CO2 X depth X position interactions for measured root variables. Significant depth X position interactions were noted. In general, a higher proportion of the potato root system grew closer to the row center (root length and mass bases) most notably at the uppermost soil depths. Elevated CO2 had no impact on the soil biology parameters evaluated in this study. Our field results suggests that increased atmospheric CO2 concentration did not alter belowground responses in potato under subarctic conditions of Alaska.