Haile-Mariam S, Collins H P, Higgins S S
Vegetable and Forage Research Unit, U.S. Department of Agriculture-Agricultural Research Service, 24106 N. Bunn Road, Prosser, WA 99350, USA.
J Environ Qual. 2008 May 2;37(3):759-71. doi: 10.2134/jeq2007.0400. Print 2008 May-Jun.
Intensive agriculture and increased N fertilizer use have contributed to elevated emissions of the greenhouse gases carbon dioxide (CO(2)), methane (CH(4)), and nitrous oxide (N(2)O). In this study, the exchange of CO(2), N(2)O, and CH(4) between a Quincy fine sand (mixed, mesic Xeric Torripsamments) soil and atmosphere was measured in a sweet corn (Zea mays L.)-sweet corn-potato (Solanum tuberosum L.) rotation during the 2005 and 2006 growing seasons under irrigation in eastern Washington. Gas samples were collected using static chambers installed in the second-year sweet corn and potato plots under conventional tillage or reduced tillage. Total emissions of CO(2)-C from sweet corn integrated over the season were 2071 and 1684 kg CO(2)-C ha(-1) for the 2005 and 2006 growing seasons, respectively. For the same period, CO(2) emissions from potato plots were 1571 and 1256 kg of CO(2)-C ha(-1). Cumulative CO(2) fluxes from sweet corn and potato fields were 17 and 13 times higher, respectively, than adjacent non-irrigated, native shrub steppe vegetation (NV). Nitrous oxide losses accounted for 0.5% (0.55 kg N ha(-1)) of the applied fertilizer (112 kg N ha(-1)) in corn and 0.3% (0.59 kg N ha(-1)) of the 224 kg N ha(-1) applied fertilizer. Sweet corn and potato plots, on average, absorbed 1.7 g CH(4)-C ha(-1) d(-1) and 2.3 g CH(4)-C ha(-1) d(-1), respectively. The global warming potential contributions from NV, corn, and potato fields were 459, 7843, and 6028 kg CO(2)-equivalents ha(-1), respectively, for the 2005 growing season and were 14% lower in 2006.
集约化农业和氮肥使用量增加导致温室气体二氧化碳（CO₂）、甲烷（CH₄）和氧化亚氮（N₂O）排放量上升。在本研究中，于华盛顿州东部灌溉条件下，对2005年和2006年生长季甜玉米（Zea mays L.）-甜玉米-马铃薯（Solanum tuberosum L.）轮作体系中，昆西细砂（混合、中湿干旱砂质新成土）土壤与大气间的CO₂、N₂O和CH₄交换进行了测定。气体样本通过安装在常规耕作或少耕的第二年甜玉米和马铃薯地块中的静态箱收集。2005年和2006年生长季，甜玉米整个生长季的CO₂-C总排放量分别为2071和1684 kg CO₂-C ha⁻¹。同期，马铃薯地块的CO₂排放量分别为1571和1256 kg CO₂-C ha⁻¹。甜玉米田和马铃薯田的累积CO₂通量分别比相邻的非灌溉原生灌木草原植被（NV）高17倍和13倍。玉米田氧化亚氮损失占施用肥料（112 kg N ha⁻¹）的0.5%（0.55 kg N ha⁻¹），马铃薯田占施用肥料224 kg N ha⁻¹的0.3%（0.59 kg N ha⁻¹）。甜玉米和马铃薯地块平均分别吸收1.7 g CH₄-C ha⁻¹ d⁻¹和2.3 g CH₄-C ha⁻¹ d⁻¹。2005年生长季，NV、玉米田和马铃薯田的全球变暖潜势贡献分别为459、7843和6028 kg CO₂当量 ha⁻¹，2006年降低了14%。
