03/10/14

Ozone eating away Indian crop yields

Copyright: Flickr/Curt Carnemark/World Bank

By: Sandhya Sekar

We encourage you to republish this article online and in print, it’s free under our creative commons attribution license, but please follow some simple guidelines:

You have to credit our authors.
You have to credit SciDev.Net — where possible include our logo with a link back to the original article.
You can simply run the first few lines of the article and then add: “Read the full article on SciDev.Net” containing a link back to the original article.
If you want to also take images published in this story you will need to confirm with the original source if you're licensed to use them.
The easiest way to get the article on your site is to embed the code below.

For more information view our media page and republishing guidelines.

The full article is available here as HTML.

Press Ctrl-C to copy

<div class="article-wrap">
<div id="article-introduction">
<h1>Ozone eating away Indian crop yields</h1>
<h4>By: Sandhya Sekar</h4>
</div>
<br />
<br />

<div id="article-body">
<p>[THIRUVANANTHAPURAM] Ozone <a href="http://www.scidev.net/south-asia/environment/pollution/">pollution</a> in the atmosphere over India is seriously impacting <a href="http://www.scidev.net/south-asia/agriculture/farming/">crop</a> productivity and may annually be eating away as much as six million tonnes of rice and wheat, enough to feed 94 million poor people, says a new study. <br />
 <br />
The study published in August in G<em>eophysical Research Letters </em>simulates the potential district-wise impact of ozone on soybean, rice, and wheat crops in India for the first decade of the century. Annual wheat and rice losses were estimated at 9.2 per cent of the cereals needed to feed 270 million poor people under India’s <a href="http://www.scidev.net/south-asia/agriculture/farming/">food security</a> laws. </p>
<p>Ozone forms a protective layer in the upper atmosphere that shields the earth from harmful ultraviolet rays. However, closer to the earth’s surface, the gas is a pollutant that adversely affects plant physiology and reduces crop quality and yields.</p>
<p>According to Sachin D. Ghude, a scientist at the Indian Institute of Tropical Meteorology (IITM), Pune and one of the authors of the study — which estimates stocks and flows of specific atmospheric gases — there is much variation in ozone levels across the country.</p>
<p>“These differences in ozone levels are due to regional differences in emissions of precursor gases like nitrous oxides and volatile organic compounds,” Ghude tells <em>SciDev.Net</em>. “For example, the Indo-Gangetic plains have higher emissions of these precursors due to high <a href="http://www.scidev.net/south-asia/environment/climate-change/">anthropogenic</a> activities — vehicular, industrial and bio-fuel burning.”  </p>
<blockquote class="quote list-left">
<h3>
		“Mitigation of nitrous oxides, particularly targeting transportation and industrial sectors, is important to reducing the ozone problem”</h3>
<h4>
		By Sachin Ghude, IITM</h4>
</blockquote>
<p>“Mitigation of nitrous oxides, particularly targeting the transportation and industrial sectors, is important to reducing the problem,” Ghude adds.</p>
<p>Denise Mauzerall, professor of environmental engineering and international affairs at Princeton University describes the model that predicts surface concentrations of ozone based on emissions, chemistry and transport, as “state-of-the-science.”</p>
<p>The study admits, in conclusion, that assessing crop yield damage is subject to several sources of uncertainty including unpredictability in the crop-growing season, emission inventories and yield reduction at different ozone exposure.</p>
<p>“The percentage of crop loss is a function not only of the susceptibility of that crop to ozone, but also the ozone values present at the locations and seasons when that particular crop is grown,” says Larry Horowitz, faculty at the National Oceanic and Atmospheric Administration, Washington. “Different crops — and even different cultivars of the same crop — respond differently to ozone.”</p>
<p>> Link to <a href="http://onlinelibrary.wiley.com/doi/10.1002/2014GL060930/abstract">abstract</a> of study in <em>Geophysical Research Letters</p>
<p>This article has been produced by SciDev.Net's South Asia desk.</em></p>

</div>
<div class="quick-links-wrapper">
<h3>You might also like</h3>
[related-articles]
</div>
<p>This article was originally published on <a href="https://www.scidev.net" target="_blank">SciDev.Net</a>. Read the <a href="https://www.scidev.net/asia-pacific/news/ozone-eating-away-indian-crop-yields/" target="_blank">original article</a>.</p>
<script type="text/javascript">
(function(e,t,n,r,i,s,o){e["GoogleAnalyticsObject"]=i;e[i]=e[i]||function(){(e[i].q=e[i].q||[]).push(arguments)},e[i].l=1*new Date;s=t.createElement(n),o=t.getElementsByTagName(n)[0];s.async=1;s.src=r;o.parentNode.insertBefore(s,o)})(window,document,"script","//www.google-analytics.com/ga.js","ga");var _gaq=_gaq||[];var _gaq=_gaq||[];_gaq.push(["_setAccount","UA-3223906-8"],["_trackEvent","article interaction","republished","https://www.scidev.net/asia-pacific/news/ozone-eating-away-indian-crop-yields/",null,true])
</script>
</div>

[THIRUVANANTHAPURAM] Ozone pollution in the atmosphere over India is seriously impacting crop productivity and may annually be eating away as much as six million tonnes of rice and wheat, enough to feed 94 million poor people, says a new study.

The study published in August in Geophysical Research Letters simulates the potential district-wise impact of ozone on soybean, rice, and wheat crops in India for the first decade of the century. Annual wheat and rice losses were estimated at 9.2 per cent of the cereals needed to feed 270 million poor people under India’s food security laws.

Ozone forms a protective layer in the upper atmosphere that shields the earth from harmful ultraviolet rays. However, closer to the earth’s surface, the gas is a pollutant that adversely affects plant physiology and reduces crop quality and yields.

According to Sachin D. Ghude, a scientist at the Indian Institute of Tropical Meteorology (IITM), Pune and one of the authors of the study — which estimates stocks and flows of specific atmospheric gases — there is much variation in ozone levels across the country.

“These differences in ozone levels are due to regional differences in emissions of precursor gases like nitrous oxides and volatile organic compounds,” Ghude tells SciDev.Net. “For example, the Indo-Gangetic plains have higher emissions of these precursors due to high anthropogenic activities — vehicular, industrial and bio-fuel burning.”

“Mitigation of nitrous oxides, particularly targeting transportation and industrial sectors, is important to reducing the ozone problem”

By Sachin Ghude, IITM

“Mitigation of nitrous oxides, particularly targeting the transportation and industrial sectors, is important to reducing the problem,” Ghude adds.

Denise Mauzerall, professor of environmental engineering and international affairs at Princeton University describes the model that predicts surface concentrations of ozone based on emissions, chemistry and transport, as “state-of-the-science.”

The study admits, in conclusion, that assessing crop yield damage is subject to several sources of uncertainty including unpredictability in the crop-growing season, emission inventories and yield reduction at different ozone exposure.

“The percentage of crop loss is a function not only of the susceptibility of that crop to ozone, but also the ozone values present at the locations and seasons when that particular crop is grown,” says Larry Horowitz, faculty at the National Oceanic and Atmospheric Administration, Washington. “Different crops — and even different cultivars of the same crop — respond differently to ozone.”

> Link to abstract of study in Geophysical Research Letters

This article has been produced by SciDev.Net's South Asia desk.