GM will solve the nitrogen crisis
GM has not delivered nitrogen-efficient crops
Synthetic nitrogen fertilizer is used in GM farming, as in all chemically-based agriculture. There are many problems associated with its production and use. The production process uses large amounts of natural gas, a non-renewable fossil fuel.21 A UK study found that nitrogen fertilizer production can account for more than 50% of the total energy used in agriculture.22
Nitrogen fertilizer produces greenhouse gases at the time of manufacture and again when used on fields,22 giving off nitrous oxide, a greenhouse gas 300 times more potent than carbon dioxide.23 Fertilizer-intensive agriculture is the largest source of human-created nitrous oxide emissions in the US24 and will be a major source in any country using chemically-based agriculture.
The profitability of farming is highly dependent on the cost of fertilizers, and the cost of nitrogen fertilizer is tied to natural gas prices.21 In Canada, a major producer, the price of nitrogen fertilizer reached a record high in 2008.25 According to some analysts, peak gas, the point at which the maximum rate of gas extraction is reached and supplies enter terminal decline is expected to arrive around 2020.26 As this point gets closer, prices will rise. Already the industry is ramping up expensive and environmentally damaging strategies, like fracking, for natural gas extraction.
For these reasons, agriculture cannot continue to depend on synthetic nitrogen fertilizer. Other ways of managing nitrogen must be found.
Some plants, including most legumes (the bean family of plants, which includes soy and peanuts), fix nitrogen directly from the air with the help of nitrogen-fixing bacteria. But other crops, such as wheat and barley, cannot do this and need to be fed nitrogen through the soil.
Proponents claim that genetic engineering can produce crops with high nitrogen use efficiency (NUE) that require less nitrogen fertilizer.
But GM technology has not produced any commercially available NUE crops.27 On the other hand, conventional breeding has successfully delivered improvements in NUE in a number of crops. Estimates for wheat from France show an increase in NUE of 29% over 35 years, and Mexico has improved wheat NUE by 42% over 35 years.27
Studies show that organic, low-input and sustainable farming methods are the key to nitrogen management. One study calculated the potential nitrogen production by such methods to be 154 million tonnes, a potential which far exceeds the nitrogen production from fossil fuel.28
Sustainable nitrogen management methods include the planting of legumes in rows between the main crop, or in a crop rotation. This makes growth-promoting nitrogen available to other plants growing nearby at the same time or planted in subsequent cropping seasons.
Study findings include:
- Planting legumes on degraded land in Brazil successfully fixed nitrogen in soil, restoring soil and ecosystem biodiversity in the process.29
- Maize/peanut intercropping (growing two or more crops in close proximity) increased soil nitrogen and nutrients, increased growth of beneficial soil bacteria, and was expected to promote plant growth, as compared with monoculture, in experiments in China.30
- Planting legume cover crops (crops planted to preserve soil) could fix enough nitrogen to replace the amount of synthetic fertilizer currently in use, according to data from temperate and tropical agroecosystems.28
Agroecological methods of managing nitrogen solve another major problem associated with the application of synthetic nitrogen fertilizer – loss of soil nitrogen though agricultural runoff. In the runoff process, nitrogen leaches from soil in the form of nitrate, polluting groundwater. It can get into drinking water, threatening human and livestock health.
Agroecological, organic, low-input, and sustainable farming practices have been found to reduce soil nitrogen losses in the form of nitrate by 59–62% compared with conventional farming practices.31 The result is reduced nitrate pollution and better conservation of nitrogen in soil.