Without water there is no life. Globally agriculture accounts for 70 percent of freshwater usage. Still almost 80 percent of the world’s agriculture is non-irrigated and therefore relies solely on rainfall.
Here in North America, we are fortunate to have vast amounts of freshwater. However, the fact remains rain and snowfall still supply a large percentage of the soil moisture required by crops in many parts of North America. This means even in the world’s bread basket many farmers have serious water issues.
For several years parts of North America have experienced lower precipitation and now have drought conditions. So what can we do about it? Contrary to popular myths we cannot control the weather. Therefore we are left with manipulating the crops to better deal with drought conditions when they arise. On average it takes 1000 litres of water to grow one kilogram of wheat. What if we could create a genetically engineered (GE) variety of wheat that only required 200 litres per kilogram?
Around the world scientists are working at developing drought resistant crops. Researchers in Egypt are field testing a variety of wheat containing a gene from barley. This genetically engineered (GE) wheat cultivar requires one eighth as much water as its conventional counterpart. At present this transgenic (produced by genetic engineering) wheat is undergoing bio-safety assessments in preparation for commercialization. Undoubtedly some farmers will be very interested in this drought tolerant wheat.
The publicly-funded International Maize and Wheat Improvement Center (CIMMYT) has been involved with crop improvements since the green revolution. Both transgenic and traditional breeding approaches to crop improvements are used. A drought tolerant transgenic wheat variety is being evaluated and may be ready for commercialization within five years. However, an interesting twist has been discovered with this research project.
It seems that under drought conditions the transgenic wheat does better than non-transgenic varieties but under adequate water conditions the transgenic wheat performs less well. Therefore researchers are looking for ways to control when the transgene (gene engineered into a crop) is turned on. There has been some excellent research looking at controlling pieces of DNA, called promoters, which will only turn genes on under specific environmental conditions. Using this controlling DNA is a type of genetic use restriction technology (or GURT). Although critics of GE crops have been very active fighting the advancement of GURT research, Canada is one of a select number of countries that has called for more research into using these technologies to improve crops.
Further, the use of another type of GURT would stop the unwanted movement of the drought tolerance trait itself. Using this type of GURT the pollen or seed of the drought tolerant crop would be sterile so there would be no transfer of the drought resistance into other crops or natural weed populations.
Monsanto is a world leader in agricultural biotechnology research and drought tolerance is going to be a popular trait in their future crop varieties.
A look at one of their research facilities shows long hallways filled with growth chambers containing drought tolerant crops in various stages of development. One particular drought tolerant corn variety is moving through the regulatory pipeline and may be ready for commercialization as early as 2010.
Under drought conditions this variety has shown a 20 bushel yield advantage over non-transgenic corn varieties. To give some perspective, the highly successful insect resistant corn varieties give between 6-14 bushels per acre yield advantages. There is little doubt farmers across North America will be very interested in these new drought tolerant corn varieties once they have passed all the regulatory evaluations required for commercialization.
The most popular type of genetically engineered crop grown around the world is engineered to be herbicide tolerant. Growing these crops results in excellent weed control and at the same time allows the farmers to practice reduced or zero tillage agriculture. The benefits have been well documented. By reducing the amount of ploughing, soil erosion and the loss of soil moisture to evaporation are greatly reduced. Therefore, growing this type of GE crop also helps with water conservation.
The other big players in agriculture biotechnology are also heavily investing in drought tolerance research. Bayer, Syngenta, Dow, BASF and Dupont all have extensive research programs in this area. At this point no one knows how many drought tolerant transgenic crops China has in development. But we can be confident it is quite a few as China has almost three times as many transgenic crops in development as the United States. The adoption rate of agricultural biotechnology is fastest in developing world.
If the current trend of climate change continues there will undoubtedly be shifts in precipitation patterns around the world. Those areas that rely on rain water for agriculture may be at risk. Along with newer drip irrigation systems, agri-forestry, and traditional plant breeding, genetic engineering of drought tolerance will play an important role in maintaining food production with less water.
Originally published Globe and Mail July 7 2006
Malaspina University College