Brewer P F, Parkhurst W J, Meeks T K
Tennessee Valley Authority, Chattanooga, Tennessee 37401, USA.
Environ Pollut. 1988;53(1-4):273-84. doi: 10.1016/0269-7491(88)90040-1.
Rural and urban ozone (O3) monitoring data for the Tennessee Valley and crop loss models developed under the National Crop Loss Assessment Network (NCLAN) were used to estimate potential yield reductions for winter wheat, corn, soybean, cotton, and tobacco during the 1982 to 1984 growing seasons. Reductions from 0 to 20% of potential crop yields were estimated due to ambient O3. Rural O3 exposures measured in the Tennessee Valley were significantly higher than the measured urban exposures, suggesting that spatial interpolation from urban O3 records may underestimate rural O3 and thereby potential crop loss. Seasonal mean O3 exposures were highest in summer 1983, and similar in 1982 and 1984. Although a consistent inverse relationship was found between measured crop yields in the Tennessee Valley and seasonal O3 exposures, annual variation in yields was much greater than attributable to the annual variation in O3. Moisture stress, as indicated by the Palmer Drought Severity Indices, is likely the major determinant for yields of nonirrigated crops. This is consistent with field studies that demonstrate that ambient O3 levels can reduce crop yields under ideal soil moisture conditions, but cause little to no detectable yield reduction for nonirrigated crops. These models could be improved if crop response to O3 were allowed to vary as a function of environmental factors such as moisture stress.
田纳西河谷的农村和城市臭氧（O₃）监测数据以及在国家作物损失评估网络（NCLAN）下开发的作物损失模型，被用于估算1982年至1984年生长季冬小麦、玉米、大豆、棉花和烟草的潜在产量降幅。据估计，由于环境O₃的影响，作物潜在产量会降低0%至20%。在田纳西河谷测得的农村O₃暴露量显著高于测得的城市暴露量，这表明根据城市O₃记录进行空间插值可能会低估农村O₃，从而低估潜在作物损失。季节性平均O₃暴露量在1983年夏季最高，1982年和1984年相近。虽然在田纳西河谷测得的作物产量与季节性O₃暴露量之间发现了一致的反比关系，但产量的年变化远大于可归因于O₃年变化的部分。帕尔默干旱严重度指数所显示的水分胁迫，可能是非灌溉作物产量的主要决定因素。这与实地研究结果一致，实地研究表明，在理想土壤湿度条件下，环境O₃水平会降低作物产量，但对非灌溉作物几乎不会导致可检测到的产量下降。如果允许作物对O₃的反应随水分胁迫等环境因素而变化，这些模型可能会得到改进。
