By Doug Gurian Sherman
The terrible drought that is wringing the life out of crops over a large swath of the country, especially in the Midwest, has understandably been in the news. There have been warnings about rising food prices, and the cost to taxpayers for disaster relief to farmers and big insurance companies that are subsidized by the federal government. And as with rising energy prices in the past, rising food prices could be another unwanted burden on a fragile U.S. economy.
In poor countries, the pain could be much worse, as higher prices for corn from the U.S. could have direct and ripple effects on crop prices.
The drought this year follows the drought last year in Texas that resulted in billions of dollars of damage.
Can anything be done to mitigate the harm from these droughts that are likely, on a global scale, to increase in severity due to climate change?
Complementary approaches are needed
It is natural when faced with challenges like this year’s drought to wonder if technology can come to the rescue. For years the crop genetic engineering (GE) industry has touted drought-resistant crops as part of its panoply of future benefits. This year, we finally have a chance to see what is emerging from the industry pipeline, after the first engineered drought-tolerant corn was approved in the U.S.
According to limited data from Monsanto, analyzed in our recent report, the new transgenic corn is unlikely to be of value in the severe to extreme droughts occurring in much of the corn belt. It may provide a modest reduction of yield loss in areas hit by moderate droughts. Based on the amount of cropland that may benefit, this may amount to an overall increase in the productivity of our corn crop of about one percent.
To put this in context, this is about half to two thirds of the average annual increase in corn yield in the U.S. It is about equal to a single year of improvement in drought tolerance due to conventional crop breeding and improved management, based on a recent study by economists at Iowa State University.
But isn’t this just the beginning? Based on our analysis of the current pipeline, and the nature of drought and drought tolerance, we should not put much stock in the prospects of GE making a big difference in the foreseeable future.
In a nutshell — or a corn kernel — this is because both drought and plant responses to drought are quite complex. By comparison, the genetics and physiology of the few successful engineered genes are much more simple—leading directly to pest control or immunity to herbicides.
Complex interactions between genes are often accompanied by tradeoffs between desirable traits. This has already been observed with several experimental drought tolerance genes.
Often neglected in our focus on GE is the largely untapped genetic potential of crops and their wild relatives that can be used in breeding for drought tolerance. In fact, conventional breeding, which is much less expensive than GE, is improving drought tolerance in many crops and will likely continue to outpace GE in coming years.
Regardless of the genetic approach, there are limits to how much can be done in the face of really bad droughts, which sometimes continue for several years.
If we can’t end losses from the most severe droughts genetically, are there other options?
Other approaches to improving resilience to drought
Soil quality is critical to crop production, and is especially important during drought. Soils with more organic material hold more water, and release it over time to the crop. Improved soil quality also reduces runoff, increasing the amount of water that filters into the soil.
Unfortunately, conversion of uncultivated lands to cropland, and industrial agricultural practices, have reduced soil organic matter in the hard-hit Midwest and elsewhere in the U.S. by about 50 percent.
The good news is that most of this organic matter could be restored. Some farming methods add organic matter to the soil.
Organic farming practices are particularly good at doing this.
Another practice that is associated with increased soil organic matter and water infiltration is no-till farming. And recent work has combined organic farming and no-till, which has the potential to achieve the best of both practices.
The bad news (you knew this was coming) is that many of our farm policies emphasize increasing the efficiency of huge monocultures of a few crops at the expense of long-term benefits to soil quality, water quality, and resilience to climate change.
Less than 30 percent of corn is farmed using no-till, which has increased little in the past decade. And conventional no-till relies on herbicides to control weeds as an alternative to plowing. Although most of the increase in no-till occurred because of incentives built into earlier Farm Bills prior to GE, the system is now locked into the use of engineered herbicide-resistant crops.
This unsustainable system has led to tens of millions of acres of herbicide-resistant weeds that are spreading rapidly, requiring the use of more and older herbicides and more plowing, and reversing earlier progress. The GE/pesticide industry’s answer is more herbicide-resistant crops designed to use older and nastier herbicides like 2,4-D. But this strategy is likely to fail, leading to more herbicide resistant weeds, more herbicide use, and more tillage.
We need far-sighted policies that encourage ecologically diverse, highly productive farming systems that are resilient to droughts, pests, and other challenges. Policies that encourage improved soil fertility and its multiple benefits need to be emphasized.
In the end, even with improved genetics and ecologically-based farming methods, the worst droughts are going to take a big toll. Eventually, even soils that have high fertility and high organic content will be depleted of water.
We need to do what we can to reduce the impact of drought and high temperatures. But ultimately, limiting climate change and the increasing drought intensity that accompanies it is the best way to reduce losses from major droughts.
About the author: Doug Gurian-Sherman is a widely-cited expert on biotechnology and sustainable agriculture. He holds a Ph.D. in plant pathology.
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