Combined Effects of Elevated Atmospheric Carbon Dioxide and Ozone on Soybean Whole-Plant Water Use

摘要: Increasing concentrations of atmospheric trace gases such CO2 and O3 might affect agricultural crop productivity in as yet unforeseen ways. A critical issue is how changes these gas will hydrologic cycles. In order to address part this question, a study was undertaken test the effects elevated on whole-plant water loss. 2-year experiment, pot-grown soybean [Glycine max (L.) Merr., Essex] exposed from emergence maturity reciprocal treatments open-top field chambers. Plants were treated with charcoal-filtered air (CF) (18 nmol mol–1) or CF plus (72 combination ambient (369 μmol (718 mol–1). Whole-plant loss monitored by measuring mass potted plants placed electronic balances each chamber. harvested weekly determine leaf area, replaced another plant previously similar treatment conditions. Seasonal average daily lower 17% 28% O3, respectively, compared control. Water both 22% than Elevated suppressed per unit area 28%, whereas not significantly affected O3–ambient treatment. use efficiency for seed production increased 45% treatments, but treatments. These results suggest that lowered because decreased stomatal conductance despite 9% more area. Decreased O3-ambient caused growth less Overall, counteracted use, growth, yield. indicate should help buffer crops against injury stress.