Assessment of Crop Loss from Ozone

Abstract

The National Crop Loss Assessment Network (NCLAN) was set up to determine more accurately crop loss from ozone, sulfur dioxide, and nitrogen dioxide. The NCLAN consists of a group of government and nongovernment organizations cooperating in field work, crop production modeling, and economic studies to assess the immediate and long-term economic consequences of the effects of air pollution on crop production. The program will define the relationships between yields of major agricultural crops and doses of O/sub 3/, SO/sub 2/, NO/sub 2/ and their mixtures. These relationships will be used to assess the primary economic consequences of the exposure of agricultural crops to these pollutants. The program is also designed to advance the understanding of cause-effect relationships with the intent of developing simulation models. These nationally-coordinated field studies are designed to provide crop dose-response data that are as free of artifact as is currently possible using state-of-the-art technology. The basic exposure technique utilizes open-top chambers. These chambers have been well tested and permit control of gas(es) around the plant canopy, allowing specific pollution regimes to be imposed on experimental plants. (JMT)