Photo - Shutterstock
Global Challenge Network on Tropospheric Ozone Agricultural and crop-effects of ozone
How does ground-level ozone affect Key Facts agricultural crops and food production? Ground-level ozone has often been ignored as a Ground-level ozone is a threat to food threat to food production; production as it has a negative impact on Current ambient ozone the yield and quality of important staple concentrations are above crops. Soybean, wheat and rice are the most the threshold where we can sensitive to ozone, with maize and barley being expect significant effects on moderately sensitive. yield and quality of sensitive crop species; Ground-level ozone is formed by a series In Europe, estimated loss of of complex chemical reactions which take wheat grain yield from ozone time to build up ozone concentrations. High was €3.2 billion in 2000; concentrations are therefore found in rural and Evidence from seven upland areas, some distance downwind of cities European countries, India and other areas where the chemical precursors and the USA indicates wheat yield increased by an average of ozone are emitted. Hot, sunny weather leads of 9% when ground-level to the highest concentrations. ozone concentrations were reduced by filtration to near Example of ozone-induced leaf damage to an agricultural crop natural levels; Photo: Dimitris Velissariou The value of salad crops (e.g. lettuce, spinach, chicory, salad onions) can be reduced by the development of ozone-induced visible damage to leaves; Current crop cultivars tend to be more sensitive to ozone than older varieties.
Links icpvegetation.ceh.ac.uk http://www.ceh.ac.uk/our-science/ research-facility/solardomes
ICP VEGETATION Recent developments What is needed? The uptake of ozone by crops Ozone pollution is a global Little is known about the impacts through the leaf pores is affected problem requiring global of ozone on fodder production by weather, soil water availability solutions. More stringent and quality. Further research on and plant development. Irrigation reductions of the emissions of this is needed to assess the impacts of crops during warm, sunny days precursors of ozone are required of ozone on for example meat and can enhance the amount of ozone across the globe to reduce the milk production and quality. taken up by leaves. threat from ozone pollution to food production. Air pollution Ozone concentrations are rising abatement policies need to be in developing areas of the world integrated with climate change (e.g. India and China) due to Ozone damage to wheat modelled for the policies as both affect global years 2000 and 2020 rapid increases in population food production. Improved and industrialization, threatening quantification of impacts of Source: Mills and Harmens (2011), icpvegetation.ceh.ac.uk global food production. ozone within the context of The background ozone climate change is urgently concentration in Europe is rising required to facilitate improved due to increases in emissions future planning of the availability elsewhere in the northern of food at a range of scales hemisphere. For example, (national, regional, global). emissions from North America may Crop breeding programmes should be contributing up to 60% of the include a test for ozone sensitivity current ozone effects on crop yield to develop more resistant varieties. in Europe. Future crop management Even with current legislation to strategies should consider ways reduce ozone pollution in Europe, of reducing ozone uptake into economic losses of wheat are still crops, for example by withholding predicted to be €2 billion in 2020 irrigation during ozone episodes. (based on wheat prices in 2000). Further research is needed to The figure on the right shows improve our ability to quantify predicted economic losses for and forecast effects of ozone on ozone effects on wheat in million crop yield and quality. Field-based € per 50 km x 50 km square in experiments are required especially 2000 (top) and 2020 (bottom). to enhance our knowledge on the impacts of ozone on crop quality, It is assumed that soil moisture is such as protein yield and content, not limiting, i.e. irrigation is used sugar and mineral content, to as needed. assess the impacts of ozone on nutritive value.
The Ozone Challenge Ozone is formed in the lower atmosphere by the action of sunlight on nitrogen dioxide (NO2), which is naturally present from lightning, biomass burning Other Fact sheets and soil emissions; man-made contributions to NO2 from burning fossil fuels in the series: dominate in developed regions. Ozone formation is accelerated by the presence Ozone monitoring of organic gases, both biogenic and man-made. Ozone is toxic to plants, animals and humans; toxic concentrations are found in polluted air, downwind Ozone modelling of NO2 sources and especially in strong sunlight. Ozone is removed from the Health effects atmosphere by deposition to plants, and also by reaction with nitric oxide (NO) of ozone to form NO2. Ecosystem effects Further information and contact details: of ozone www.ozone-net.org.uk