Planting the future: opportunities and challenges for using ... - EASAC

By comparison, Argentina alone performed 72 field
trials in 2011 10 .
2.3 Reported impacts and the implications
for science, innovation and regulation in
comparator countries
2.3.1 Reported impact of GM herbicide-tolerant
soybean in Argentina
Cumulative gross benefits of adopting GM crops
for Argentina have been estimated at over US$72
million, with most of the reported benefits accounted
for by soybean production (US$65 million for
herbicide-tolerant soybeans, US$5 million for GM
maize and just under US$2 million for insect-resistant
and herbicide-tolerant GM cotton; Trigo, 2011).
Argentina’s capacity to act as an ‘early adopter’ was
reported to be critical because it allowed the country
to benefit from initial low levels of competition in
international markets and higher commodity prices
(Trigo, 2011).
The expansion of GM soybean production was
accompanied by profound changes in the Argentinean
economy that favoured the geographical concentration
of agricultural production and development of largescale
operations. Soybean production expanded
as a monoculture, or as a wheat–soybean doublecropping
system (Bindraban et al., 2005). Bulk export
of soybeans also led to an increase of farm size due to
the financial benefits from economies of scale (Manuel-
Navarrete et al., 2009). These factors promoted
input-oriented and process-oriented practices, with
a significant increase in the level of mechanisation
(Bindraban et al., 2009; Manuel-Navarrete et al., 2009).
The adoption of GM soybean fitted these systems
well and therefore contributed to the expanded scale
of production even though this is not essential for
beneficial deployment of the technology (for example,
in Brazil, this increase in farm sizes took place before
the adoption of GM soybean, see Appendix 3). About
50% of the soybean crop sown in the 2002/2003
season was planted in areas that were not cultivated in
1998 (LART–FAUBA, 2004). This raised concerns about
the potential adverse impact on fragile ecosystems in
Argentina if there was a gradual expansion of soybean
production (Bindraban, 2009; Trigo, 2011). Extensive
monoculture has also raised concerns about the
sustainability of this agronomic practice (Bindraban
et al., 2009; Trigo, 2011).
There is a consensus that herbicide-tolerant GM
technology does not have a significant impact on yield,
because differences reported are largely accounted for by
differences in the specific genetic background into which
the GM trait was introduced, and by differences in agroclimatic
conditions (da Silveira and Borges 2005; Smale et
al., 2006; Bindraban et al., 2009).
The direct environmental impact of growing GM
soybeans relates mostly to changes in weed control
practices. Compared with many other herbicides, the
eco-toxicity of glyphosate is lower with shorter residual
effects in soil and water. A further benefit of the
technology is the ability to adopt no-till farming practices
which prevent soil erosion, loss of water and nutrients,
and reduced fuel consumption (Qaim and Traxler, 2005;
Kleter et al., 2007, Bindraban et al., 2009; Brookes and
Barfoot, 2012; Trigo, 2011) 11 .
Negative environmental impacts have also been
reported. These include an increase in herbicide
use (because application rates are generally higher
compared with conventional counterparts) for
herbicide-tolerant soybean and in no-till systems
independently of whether the crop grown is GM or
conventional (Bindraban et al., 2009; Trigo, 2011,
Brookes and Barfoot, 2012). The environmental impact
of herbicide-tolerant soybean has been estimated to be
higher than that of conventional soybean in one study
(Bindraban et al., 2009) and lower in separate studies
(Brookes and Barfoot, 2006, 2012). The difference in the
conclusions can be accounted for by different sources
of data and the fact that the former study focused on
the main soybean cropping areas of Argentina where a
higher level of inputs tend to be used rather than on the
country as a whole (Bindraban, 2009).
Extensive glyphosate use has also resulted in the
emergence of glyphosate-resistant weeds, a factor that
threatens to erode the benefits of herbicide-tolerant GM
technology (Cerdeira et al., 2006, 2011; Christoffoleti
et al., 2008; Powles, 2008; Bindraban et al., 2009).
Farmers tend to increase glyphosate applications to
control herbicide-resistant weeds, which exacerbates the
problem. A further negative consequence of the high
level of production of soybean in Argentina (albeit not
directly linked to GM technology because it would occur
with any crop) is the loss of phosphate from the soil,
estimated to amount to 14 million tons between 1996
and 2010 (Trigo, 2011) 12 .
10
http://64.76.123.202/site/agregado_de_valor/biotecnologia/50-EVALUACIONES/___historica/_archivos/liberaciones_ogm_2011.
pdf.
11
Glyphosate replaced imidazolines for broad-leafed weeds and soil-incorporated triazines for controlling grass weeds (although
these are still used to address residual weed problems in GM plantations, whereas glyphosate is also used in conventional
plantations as a pre-emergence herbicide; Kleter et al., 2007).
12
GM plants able to metabolise phosphite as a source of phosphorus are currently being developed (López-Arredundo and
Herrera-Estrella, 2012).
12 | June 2013 | Planting the future EASAC