While a recent report tells us current droughts in the western USA hardly make the top ten, we have this from Stanford University, a claim about drought related crop insurance claims that doesn’t seem to match data on national yields and trend. While the 2012 drought had an impact, 2013 saw the third highest corn yield on record.
Data: http://quickstats.nass.usda.gov/results/90C69DEC-38D6-31B4-9953-4C6EB5E82D79?pivot=short_desc
U.S. corn yields are growing more sensitive to heat and drought, according to research by environmental scientist David Lobell. Farmers are faced with difficult tradeoffs in adapting to a changing climate in which unfavorable weather will become more common.
By Laura Seaman (Stanford writer)
Research by David Lobell of Stanford’s Center on Food Security and the Environment indicates corn harvests will be affected by drought conditions, which are occurring more often.
Corn yields in the central United States have become more sensitive to drought conditions in the past two decades, according to Stanford research.
The study, which appears in the journal Science, was led by Stanford’s David Lobell, associate professor of environmental Earth system science and associate director of the Center on Food Security and the Environment. “The Corn Belt is phenomenally productive,” Lobell said, referring to the region of Midwestern states where much of the country’s corn is grown. “But in the past two decades we saw very small yield gains in non-irrigated corn under the hottest conditions. This suggests farmers may be pushing the limits of what’s possible under these conditions.”
He predicted that at current levels of temperature sensitivity, crops could lose 15 percent of their yield within 50 years, or as much as 30 percent if crops continue the trend of becoming more sensitive over time.
As Lobell explained, the quest to maximize crop yields has been a driving force behind agricultural research as the world’s population grows and climate change puts pressure on global food production. One big challenge for climate science is whether crops can adapt to climate change by becoming less sensitive to hotter and drier weather.
“The data clearly indicate that drought stress for corn and soy comes partly from low rain, but even more so from hot and dry air. Plants have to trade water to get carbon from the air to grow, and the terms of that trade become much less favorable when it’s hot,” said Lobell, also the lead author for a chapter in the U.N. Intergovernmental Panel on Climate Change (IPCC) Fifth Assessment Report, which details a consensus view on the current state and fate of the world’s climate.
Rain, temperature, humidity
The United States produces 40 percent of the world’s corn, mostly in Iowa, Illinois, and Indiana. As more than 80 percent of U.S. agricultural land relies on natural rainfall rather than irrigation, corn farmers in these regions depend on precipitation, air temperature and humidity for optimal plant growth.
According to the research, over the last few decades, corn in the United States has been modified with new traits, like more effective roots that better access water and built-in pest resistance to protect against soil insects. These traits allow farmers to plant seeds closer together in a field, and have helped farmers steadily raise yields in typical years.
But in drought conditions, densely planted corn can suffer higher stress and produce lower yields. In contrast, soybeans have not been planted more densely in recent decades and show no signs of increased sensitivity to drought, the report noted.
Drought conditions are expected to become even more challenging as temperatures continue to rise throughout the 21st century, the researchers said.
Lobell said, “Recent yield progress is overall a good news story. But because farm yields are improving fastest in favorable weather, the stakes for having such weather are rising. In other words, the negative impacts of hot and dry weather are rising at the same time that climate change is expected to bring more such weather.”
Extensive data
Lobell’s team examined an unprecedented amount of detailed field data from more than 1 million USDA crop insurance records between 1995 and 2012.
“The idea was pretty simple,” he said. “We determined which conditions really matter for corn and soy yields, and then tracked how farmers were doing at different levels of these conditions over time. But to do that well, you really need a lot of data, and this dataset was a beauty.”
Lobell said he hopes that the research can help inform researchers and policymakers so they can make better decisions.
“I think it’s exciting that data like this now exist to see what’s actually happening in fields. By taking advantage of this data, we can learn a lot fairly quickly,” he said. “Of course, our hope is to improve the situation. But these results challenge the idea that U.S. agriculture will just easily adapt to climate changes because we invest a lot and are really high-tech.”
Lobell and colleagues are also looking at ways crops may perform better under increasingly hot conditions. “But I wouldn’t expect any miracles,” he said. “It will take targeted efforts, and even then gains could be modest. There’s only so much a plant can do when it is hot and dry.”
Laura Seaman is the communications and external relations manager for Stanford’s Center on Food Security and the Environment, a joint program of Stanford’s Freeman Spogli Institute for International Studies and the Stanford Woods Institute for the Environment.
For more Stanford experts on climate change and other topics, visit Stanford Experts.
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This graph suggests to me that U.S. corn is far more tolerant of drought now than it was in the dustbowl years:
![CornYieldTrend_US[1]](http://wattsupwiththat.files.wordpress.com/2012/12/cornyieldtrend_us1.gif)
“Claim: U.S. corn yields are increasingly vulnerable to hot, dry weather”
There is some truth to this despite the growth in corn yields, although climate change doesn’t have much to do with it.
Corn is one of the most water intensive agricultural crops, yet it is increasingly being grown in dry areas where it’s cultivation is entirely dependent on artificial irrigation.
Mosher:
“C02 is a trace gas. It cant warm the earth or make plants grow.”
Maybe you’re right, and if anyone were to believe .04% is too small a percentage of the atmosphere to do one thing, they should also believe it’s too small a percentage to do ANY thing.
But I know YOU don’t believe the first thing, so what are you saying about the second thing? Are you agreeing with the comment you replied to, that extra CO2 should help crop yields, or are you disagreeing with it? I have to assume you’re completely agreeing with it…if not then there might be something wrong with your assumption that the 2 things (ability to warm atmosphere/ability to make plants grow) are necessarily equivalent and their truth or falsehood can’t be evaluated independently, but instead must be fully accepted or fully rejected as a package.
Regardless, I think very few people here believe the first thing, so I think whatever “point” you were trying to make will largely fall on deaf ears.
How much of that 40% is grown for ethanol? And what % of the ethanol crop is not artificially irrigated?
Shut down the ethanol production and what % of that crop acreage could be feasibly shifted to food production to reduce the number of people dying from malnutrition every year?
Steven Mosher says:
May 3, 2014 at 6:38 am
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Really? Have you ever tried to grow a plant without CO2 in the air?
Steven Mosher says:
May 3, 2014 at 6:38 am
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My dear Mr. Mosher, please excuse my flippancy. Carbon ditaxable is essential for the growth of plants and bureaucracies, but seems to have no effect on the warmth of the earth.
Increasing CO2 increases plant growth and decreases water use dramatically. Rarely mentioned is that it also increases the ideal growth temperature which even further increases growth. Indoor gardeners that use CO2 supplementation and high intensity lights know this. We are always battling with excess heat from the lights. For my favorite plants (a C3), with CO2 at 1,400 ppm, ideal growth temperature moves from about 85F to about 90F.
Corn heads North to Canada:
http://m.startribune.com/business/?id=255584181
If global warming is really happening and a threat to corn growing in the south it will also be a boon to corn growing in the north. The corn belt will move north and judging by the land configuration probably increase the amount of land in it. It won’t take a government program to fix, farmers will plant corn in the corn belt because that’s where they can make a profit at it, that is, unless the government gets involved and pays them to continue growing corn where it won’t grow anymore. If the government doesn’t intervene GW will most likely increase the harvest. There is no problem except the possibility of government solutions.
Stephen Mosher – I thought you should know someone has hijacked your account and is posting bozo comments on WUWT.
Your pal,
Around 40% of the U.S. corn crop is used to produce ethanol. IF the study is right then we should divert production away from corn to fuel? No? Of course they won’t.
http://www.aei.org/article/energy-and-the-environment/alternative-energy/production-of-corn-ethanol-as-an-automotive-fuel-source-should-cease/
Just wondering how they control for factors unique to the non-irrigated land. To what extent has this been marginal or intermittent land, that is now in production because corn price increases are making the economics favorable? To what extent is the land not irrigated because of individual farm economics?
You maybe right since Warmists call co2 a toxin. By the way co2 can warm the Earth just like water vapour and CFCs.
Mike Borch says:
May 3, 2014 at 5:51 am
“I am a corn and soybean farmer from northern iowa. Technology in agriculture is expanding at a very rapid rate. The ability of the plant breeders to produce new and varied corn hybrids is remarkable. The goal is to DOUBLE the yields by 2050. I think there is an excellent chance that will happen if not before. The biggest threat we face is that government will get in our way!”
Yes and if we look at the current World record held by a farmer from Iowa that is achievable:
Childs (Iowa) sets new world record for 394 bushel of corn per acre
http://www.hpj.com/archives/2000/0224tocorntxtHTM.cfm
In any case does the optimum growth latitude for grains not move 170 degrees North for every 1 C increase in temperature. That being so, if we accept the alarmist predictions there will be plenty of land and water from melting glaciers in Greenland to compensate any reduced yield as well as a major potential to improve yields in Africa to the current US level – provided the Greens do not succeed in denying those farmers the fuel, hybrid seeds and agricultural chemicals to do.
I live in Northern Illinois. We get changes in the weather here all the time! Now, as I listened to the farm reports a couple of years ago they were in trouble because we weren’t getting the rains we needed. Last year was good, though, just like you said. This year we’ve had snow cover and rain, so if anything the farmers have had to delay planting because the ground wouldn’t support the equipment. If the trend for this year keeps up as it has, I think we might have another good year.
If anything, the ongoing chatter about “Frankenfood” may hurt farmers. Most corn and soybean seems to be a Monsanto product, and the do-gooders are telling us every chance they get that genetically-engineered foods are no good for you and that you should go to the organic stores and buy food at three times the price of what you get in the supermarket.
And why is that?
Steven Mosher says:
May 3, 2014 at 6:38 am
C02 is a trace gas. It cant warm the earth or make plants grow.
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Did you forget your sarc tag?
In 2013 87.2 million acres were planted in corn, with 13.99 billion bushels produced – for an average 160/bu per acre yield. There were 4.9 billion bushels dedicated to ethanol production, or 35%.
However, each of those bushels, weighing 56 pounds, used for ethanol produced 2.8 gals of ethanol AND 17.5 pounds of distillers dried grain animal feed. DDG are a high quality animal feed that replaces a large share of the corn used to produce ethanol. Because of the superior feed value each pound of DDG replaces appx 1.3 pounds of feed corn.
The 17.5 pounds of DDG replace appx 23 pounds of corn. Appx 41% of each bushel of corn used for ethanol is returned as DDG feed – meaning that instead of 4.9 billion bushels, the ACTUAL NET corn after the DDG feed replacement is appx 2.9 billion bushels. Instead of 35% of the corn crop being used to produce ethanol – the NET actual corn used after return of DDG feed is only appx 20.7%
The claim that corn dedicated to ethanol is taking land away from food production is false. The US is the worlds largest corn supplier – producing over 40% of the world corn crop. It is also the worlds corn supplier – providing more than 60% of world corn imports for many years. Even in the drought year of 2012 the US still exported more corn than every other major corn supplier combined.
The US meets 100% of the domestic demand, for feed, fuel, and food. They also provided 100% of the export demand, including for feed corn AND for white corn – which is what Mexico, Guatemala and all those other places eat. These countries import US white corn because it costs LESS, not more as claimed – and it helps LOWER food costs for these importing countries. It also allow s their farmers to grow more valuable crops for export.
It seems to me that many of these ‘studies’ don’t show alarming things that have happened, only what might happen. Yahoo news runs an article every day about the terrible things that might happen if the alarmist computer models come true.
Every indication I see is that the models are hopelessly wrong.
That said, I certainly think we should have a long term energy plan to lessen CO2 output over the next hundred years and that plan should be mostly nuclear. There is risk to adding CO2 to the atmosphere indefinitely. Problem is that no one knows so we should have a rational discussion and then a plan. Nuclear power seems to be a great compromise, but many of the most vocal proponents of AGW seem quite unwilling to compromise, even if it hurts those they say they want to protect.
We are unfortunately dealing with many zealots who seem unable to rationally discuss solutions.
Plenty of corn is grown in Arizona – where temps are regularly 110+ … and where they see yields above 200 bushels per acre. Corn in AZ is irrigated, but shows these claims that heat affects corn yield are outright ridiculous. IF temps increase enough in the Midwest the same seed as used in AZ could be used there – and get similar yields. IF that occurred we would also see a major expansion into Canada In such event production would increase.
Corn being the topic, I have to go off-topic to mention a May 1 WSJ article titled “Sizing Up Wheat in Parched Midwest Fields” by Tony C. Dreibus.
File it under weather is not climate.
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R Taylor says:
May 3, 2014 at 7:50 am
Steven Mosher says:
May 3, 2014 at 6:38 am
Steven Mosher reminds me of Rodney Dangerfield – the I don’t get no respect comedian. The one liners, such as today’s CO2 comment, are the on-stage meant to be laughed at spurts of silliness. It is reported that off-stage Dangerfield was gentlemanly and intelligent and resented being seen as obnoxious. When Mr. Mosher provides a thoughtful data-driven comment he, also, is worth listening to and deserving of respect.
Who knew Mosher had a sense of humor ?
Mr Mosher don’t tell any greenhouse growers otherwise you will put this company out of business.
http://www.johnsongas.com/industrial/CO2Gen.asp
“The Johnson CO2 Generator automatically provides the carbon dioxide to meet maximum growing potentials – and operates for only pennies a day”
Nancy C says:
May 3, 2014 at 7:47 am
Mosher:
“C02 is a trace gas. It cant warm the earth or make plants grow.”
Maybe you’re right, and if anyone were to believe .04% is too small a percentage of the atmosphere to do one thing, they should also believe it’s too small a percentage to do ANY thing.
While 0.04% is less than one part per thousand in the atmosphere, it cant have much of an effect on the total atmosphere. However, compared to the baseline of 275 ppm it represents a 45% increase in fertilizer delivered to the plants. This surely has some effect.
Then why are we burning coal in our gas tank. Especially when we have 500 – 1000 years of Coal, oil, NatGas?
The final graph looks quite like the rise in global atmospheric CO2 above a base line requirement of about 200ppmv.
Since anything that increases in a way roughly similar to CO2 is deemed to be caused by CO2, why go any further. It’s “robustly” proven that current corn production is “unprecedented”.
If this trend continues the whole of surface of the lower 48 will be infested with corn by 2100.
We must act now. to reduce atm CO2 before it’s too late.