Pollution causes yield loss in wheat, expert warns

CANBERRA — During a field visit to the wheat-growing region in India in February, CSIRO agricultural scientist Dr. Tony Fischer was shocked at the level of pollution evident. But in engaging with agricultural scientists in the region to discuss the impact on food production, he found that it was not a topic of interest.

“I didn’t find much concern about it from agricultural scientists,” Fisher explained to Devex, talking about his visit to the states of Bihar, Uttar Pradesh, Haryana, and Punjab. “I raised the question with the government and they kind of shrugged it off — what were they going to do about it as agricultural scientists?”

Tropospheric ozone is a major component of smog, and aerosol pollution produces fine particles of solids or liquids emitted into the air including car and industrial emissions. Research on these topics can show the impact of emissions on the planet, but to date, the research on the impact of food production through wheat yield has been scattered with its access limited to agricultural scientists and agronomists — who Fischer believes should be at the cutting edge of this topic.

“The information seems to be hidden in other journals,” he said. “I felt it needed to be brought out.”

Both forms of pollution have the impact to change the environmental conditions for plants — including by reducing the time plants are exposed to sunlight and potentially impacting the micronutrient and protein content of a plant.

Focusing on India, the research by Fischer examined 20 years of estimations made on wheat yield losses due to elevated tropospheric ozone and aerosol pollution. His work found that reasonable estimate could be made on yield losses from 2010 and suggests that tropospheric ozone causes two-thirds of loss, with the impact of loss of sunlight from aerosols accounting for the other third.

And his estimates put wheat yield loss of 30% because of these factors, independently backing up research conducted by environmental scientist Jennifer Burney from the University of California San Diego cited in the paper.

“I’d had a long correspondence [with] Burney saying their statistics was stretching the data — it appeared too high,” Fischer explained. “Lo and behold I came up with the same number they did four years later.”

Drawing attention to the research

Fischer’s paper has been available for the agricultural community for over a month, and he is waiting for engagement and conversation to begin. But it has been slow going.

“I haven’t received any feedback,” he said.

The aim of the paper is to get a conversation of both prevention and adaption solutions and to highlight a new impact on the effects of coal generation and coal-fired plants.

“There are some policies happening in India — but they have been slow,” Fischer said. “They are doing a big push for eliminating cow manure in cooking and are pushing to gas and electrification of transport systems. “

From the side of agricultural researchers and farmers, Fischer said there are important things they should be doing to limit pollution — including stopping the burning of crop residue which is causing health effects in northwest India and east Pakistan during November.

“The laws are that they are not supposed to burn the rice wheat straw, but it is an easy option,” Fischer said. “Now the health effects are skyrocketing — and this is an issue that needs to be taken seriously by everyone.”

Other sources of pollution do not necessarily have a direct agricultural origin, but Fischer said this should not mean it should be ignored by the sector who appear to be taking the path of least resistance.

“Other pollution comes from coal-fired power, it comes from diesel engines, automobiles, cooking fires where people are using cow dung. It’s commonly related to fossil fuels,” Fischer said.

Elsewhere tackling tropospheric ozone and aerosol pollution has been shown to have a positive impact on yield, creating an economic and food security case for tackling this issue in low- and middle-income countries.

“Developed countries in Europe and the United States brought their levels of ozone and aerosol down remarkably — and there have been crop yield increases simply because of the control of pollution,” Fischer said. “This has been documented in the United States.”

Despite Fischer’s work focusing on India, he said the findings were applicable to regions that were hotspots for tropospheric ozone and aerosol pollution — including China, India and South-East Asia. And by making the research accessible, Fischer wants to see serious policy discussion in these regions to the problem.

The risk of inaction, he said, could not only see countries struggling to feed their population but also face worsening health crises caused by pollution.

“We know how to solve it — it is solvable,” Fischer said. “It just takes determination to make it happen.”