Weeds are harmful to crops as they can block sunlight and
compete to absorb nutrients necessary for the crops to survive (Frick & Johnson, 2012). Picking them by hand is inefficient because it requires more time and people to do it and it requires the rows of crops to be farther apart. Tilling the soil gradually erodes the soil, resulting in soil with fewer nutrients and therefore a reduction in crop yields. The solution to this is herbicides such as RoundUp, which is manufactured by the company Monsanto and uses the active ingredient glyphosate. However, herbicides are problematic because they not only kill weeds, but also the crops. Enter genetically modified organisms such as corn, wheat and soy. These allow farmers to spray the entire field with herbicides and greatly increase crop yields.
Genetically modified organisms, or GMOs, are living things that have had new genes inserted into their DNA (deoxyribonucleic acid) in order to improve them or make them more useful in some way. Humans have been modifying genes since the beginning of time using selective breeding. Now, however, with genetic engineering technology, we can modify the DNA of plants and animals using genes that come from entirely different species. Unfortunately, although GMOs are engineered to create certain benefits such as being resistant to herbicides, there are often many unintended consequences that can make GMOs dangerous and must be monitored carefully.
Creating an Herbicide-Tolerant GMO
The creation of a GMO involves isolating a gene that controls a desirable trait in a species and inserting it into the cell of another. When creating the RoundUp tolerant, or RoundUp Ready crops, researchers discovered that geraniums remained largely unaffected when sprayed with RoundUp (Roundup ready soybeans, n.d.), meaning that geraniums have a gene that makes them tolerant to glyphosate (the active ingredient in RoundUp). Scientists isolated this gene using restriction enzymes to cut off the DNA that codes for glyphosate tolerance. This DNA was later inserted into the cell of a soybean plant using Ti plasmids. A Ti plasmid is a small, circular DNA molecule, found in the cells of agrobacterium, that carries T DNA, which carries genes that can lead to tumors. Once again using restriction enzymes, the T DNA is split open. Between the two ends, the new DNA from the geranium was inserted. The enzyme DNA ligase joined the new segment of DNA to the T DNA. The T DNA is inserted back into the agrobacterium. The agrobacterium then attaches itself to a soybean plant cell. A copy of the plasmid then integrates into the plant’s DNA, which is used to grow a soybean plant (Powell & Maurer, 2015) that can tolerate the pesticide RoundUp.
This technique is new and is now used in place of the Gene Gun in the case of RoundUp Ready soybeans. The gene gun shoots DNA-coated gold particles into plant cells or tissue. Gene guns are advantageous because they work on a larger variety of plants than the agrobacterium, however scientists prefer to use agrobacterium as it gives them more control over the genes transferred (Byrne, 2014).
RoundUp Ready crops have the ethical benefits of allowing farmers to produce food at a lower cost (Stebbins, 2016), resulting in cheaper food for everyone and thereby increased access, particularly for those in poverty. This result occurs because fewer plants die due to weeds and herbicides and because the rows of crops can be grown closer together. Unfortunately, however, the benefits to this GMO come with consequences that could be disastrous.
The main problem with GMOs is that they can be patented. The aforementioned company Monsanto, which owns both RoundUp and RoundUp Ready seeds, has also made all seeds that are sold sterile, meaning that farmers must buy new seeds each year. If an organic farmer is surrounded by RoundUp Ready crop farmers and the GM crops accidentally grow on his/her land, the organic farmer can potentially lose credibility and be sued by Monsanto. Furthermore, Monsanto prevents independent studies from being done by requiring an agreement to be signed upon purchase of the seeds. The agreements “explicitly forbid the use of the seeds for any independent research” (The Editors, 2009), meaning that all studies must be approved by Monsanto and are therefore strongly susceptible to bias and even false results. Without impartial scientific study, we cannot know whether or not GM crops are truly harmless to our health and the environment.
Herbicide-resistant crops are said to be environmentally friendly because they reduce or even eliminate the need to till the soil, a process done before crop seeds are planted. Tilling removes weeds, but loosens the earth, making the soil more vulnerable to wind or water erosion. Reducing erosion is beneficial to the environment because it allows farmers to grow crops on the same field for longer periods of time. Tillage erosion can reduce crop yields by up to 40%, so herbicide-resistant GMOs also beneficial to farmers trying to increase productivity (Ritter, 2015).
There is, however, an enormous environmental disadvantage to using herbicide-resistant GMOs. If spraying RoundUp, a toxic herbicide, does not negatively impact the crops, farmers can kill weeds more efficiently by spraying the entire field with herbicide. The problem comes when runoff, which is then full of herbicide, goes into streams, rivers and groundwater, polluting the water system. As glyphosate is by far one of the least potent herbicides, farmers have been able to keep the glyphosate content of water low enough to be nontoxic, but, by spraying herbicides liberally, the rate at which herbicide-resistant weeds develop is increasing fast. This develops the need for larger amounts of RoundUp, or even stronger, more dangerous herbicides that will bring toxicity levels in water to dangerous levels (Hoffman, 2013), both for nature and those whose main water source is polluted.
GMO crops are widely used in agriculture, but extremely controversial. The herbicide-tolerance gene, which has been added to food crops such as soy, corn and wheat has the benefit of increasing crop yields and thereby lowering the price of food. However, it has negative ethical and environmental consequences that cannot be overlooked. Studies conducted on the effects of RoundUp Ready crops are not independent and therefore unreliable while an increase in the total volume of RoundUp and other herbicides used pollutes the water system. Although RoundUp Ready GMOs are dangerous, we should not rule out GMOs entirely as a source of food. It’s possible that others could be more beneficial and less dangerous, but determining that will require independent scientific study and regulation to ensure that no lasting damage is done to humans or the environment.
Boston University. (2013, December 18). How are organisms genetically modified? Retrieved April 06, 2017, from http://sphweb.bumc.bu.edu/otlt/MPH-Modules/PH/GMOs/mobile_pages/GMOs3.html
Byrne, P. (2014, August). Genetically modified (GM) crops: Techniques and applications. Retrieved April 06, 2017, from http://extension.colostate.edu/topic-areas/agriculture/genetically-modified-gm-crops-techniques-and-applications-0-710/
Frick, B., & Johnson, E. (2012). Weeds – when are they a problem? Retrieved April 05, 2017, from http://www.oacc.info/Extension/ext_weed_problem.asp
Hoffman, B. (2013, July 02). GMO crops mean more herbicide, not less. Retrieved April 06, 2017, from https://www.forbes.com/sites/bethhoffman/2013/07/02/gmo-crops-mean-more-herbicide-not-less/#6af0844b3cd5
Powell, C., & Maurer, A. (2015, August 10). How to make a GMO. Retrieved April 06, 2017, from http://sitn.hms.harvard.edu/flash/2015/how-to-make-a-gmo/
Ritter, J. (2015, October). Soil erosion - causes and effects. Retrieved April 05, 2017, from http://www.omafra.gov.on.ca/english/engineer/facts/12-053.htm#6
Roundup ready soybeans. (n.d.). Retrieved April 06, 2017, from http://steveontario_15.tripod.com/geneticallymodifiedsoybeans/id1.html
Stebbins, M. (2016, April 29). 3 ways GMOs keep the cost of food down. Retrieved April 06, 2017, from https://www.forbes.com/sites/gmoanswers/2016/04/29/3-ways-gmos-keep-cost-of-food-down/#58d46d701261
The Editors. (2009, July 10). Do seed companies control GM crop research? Retrieved April 06, 2017, from https://www.scientificamerican.com/article/do-seed-companies-control-gm-crop-research/