Effects of Ozone and Sulfur Dioxide on Alfalfa Yields and Hay Quality

摘要

Alfalfa (Medicago sativa) is an extremely important crop in California, ranking below number 1 cotton and number 2 grapes in dollar value. An air pollution effects experiment more nearly approximating 'field conditions' was initiated at the University of California San Joaquin Valley Research and Extension Center near Reedley in the spring of 1979. Ambient ozone concentrations reduced Moapa yields approximately 8 to 13% but had no measureable effect on variety WL-512. Exposure to a SO2 concentration of 10 PPHM for six hours four times per week reduced yields by both varieties approximately 9%.