GMO Myths and Truths

6.3 Myth: GM will solve the nitrogen crisis
Truth: 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 US 24 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.
GMO Myths and Truths 103