One of the major arguments for the genetic engineering of plants is that such work could greatly increase the yield of farmers' crops. Engineering for yield-increasing characteristics could decrease the land area being used for crop cultivation. It also could provide food for many more people than current cultivation provides -- so aiding in the global fight against hunger. Scientists work towards these ends by engineering for insect resistance and herbicide resistance. Research has found that such engineering may, in fact, increase the yields of certain crops. For example, in their April 2000 report, Fernandez-Cornejo et al. analyzed the findings of USDA surveys on the cultivation of genetically engineered crops. Their researchers found that the use of herbicide-tolerant GE (genetically engineered) plants significantly increased the yields and net returns of cotton and soybean crops. The cultivation of insect-tolerant GE plants also significantly increased the yield and net returns of cotton crops as compared to conventional cotton crops (Fernandez-Cornejo, 2000). In 1997, similar results were found with the cultivation of insect-tolerant GE corn. In that year, U.S. farmers using this GE corn experienced a 7 percent increase in yield per acre. This increased yield translated into an average increased net return to farmers of $16.88 per acre (Moffat, 1998). These findings regarding crop yields of genetically engineered plants demonstrate the possibility of this technology producing more plants per acre than conventionally bred plants. It is important to note that these studies do all call for more research to determine the changes in yield for more crop-types and in different cultivation habitats.

A second argument for the ecological benefits of genetically engineered crops is that the use of herbicide or insect tolerant gm crops may reduce the amounts of herbicides and pesticides that farmers need to apply to their crops. In 1999, the Farm Bureau and Phillip Morris polled farmers and consumers to determine the popular attitude towards this work. 73 percent of consumers were willing to allow genetic engineering if it would decrease the amount of agrochemicals being used in farming. 68 percent considered the use of these agrochemicals a major threat to ground and surface water sources (USDA, 2000). Whether or not the use of genetically engineered crops actually changes the amount of agrochemicals used is a complicated question to answer. Studies have shown that, for certain types of crops, genetic engineering does in the end reduce the amounts of pesticides and herbicides applied to crops. They have also demonstrated a change in the types of agrochemicals applied to crops with the use of GE plants. For example, a 2000 USDA study concluded that the adoption of GE crops may allow farmers to use different mixes of pesticides at lower applicatio rates than average (USDA, 2000). The same study found that the cultivation of herbicide-tolerant plants led to the substitution of less environmentally-toxic herbicides for traditionally used herbicides (USDA, 2000). A similar study of agrochemical use showed differing effects for different types of crops. The shift to GE herbicide-tolerant cotton did not lead to a significant changes in herbicide use by farmers; while shifts to GE herbicide-tolerant soybeans and GE insect-tolerant cotton led to significant reductions in herbicide and insecticide use respectively (Fernandez-Cornejo et al., 2000). These and similar studies seem to demonstrate an overall reduction in agrochemical use with the adoption of GE crop cultivation. They also show that the types of agrochemicals used change with this adoption. These studies do highlight certain crops in which these trends are not followed. Because of this evidence, it is clear that genetically engineered crops do show promise in reducing agrochemical use, but that further research needs to be conducted on specific crop types in order to determine the extent of that promise.

Research into the potential of genetically engineered crops for the reversal of environmental pollution is in its beginning stages. GE crops have not been widely used in this manner, and so little solid research has been conducted on this potential use. Researchers are hoping to develop GE plants that can clean pollutants from soil, sediment, and water sources. Scientists are looking into the possibility that GE plants may be able to remove heavy metals from polluted soils and then store these toxic substances in their cells. The plants could then be harvested and so the toxins removed from the soil. Scientists are also studying GE plants' potential for changing highly toxic pollutants in the soil into less toxic versions of those pollutants (Wolfenbarger and Phifer, 2000). A team of researchers has found evidence that Indian Mustard plants can be genetically engineered to accumulate and tolerate higher concentrations of heavy metals from the soil than their conventional counterparts (Liang Zhu et al., 1999). Although research like this may lead to very explicit ecological benefits of GE plants, it is only in its beginning stages. More research will have to be done to determine the validity of this potential ecological benefit of genetically engineered plants.