Skip to Content.
Sympa Menu

livingontheland - [Livingontheland] New Soil Association report shows GM crops do not yield more

livingontheland@lists.ibiblio.org

Subject: Healthy soil and sustainable growing

List archive

Chronological Thread  
  • From: "Tradingpost" <tradingpost@lobo.net>
  • To: livingontheland@lists.ibiblio.org
  • Subject: [Livingontheland] New Soil Association report shows GM crops do not yield more
  • Date: Sat, 12 Apr 2008 15:34:50 -0600



New Soil Association report shows GM crops do not yield more - sometimes less
Soil Association, PRESS RELEASE, 10 April 2008
http://www.soilassociation.org/web/sa/saweb.nsf/89d058cc4dbeb16d80256a73005a2866/3cacfd251aab6d318025742700407f02!OpenDocument

Coinciding with a manifesto from Country Life launched today, which urges
people to 'learn to love GM crops', the Soil Association has published a
report on the latest available research on GM crop yields over the last ten
years. The yields of all major GM crop varieties in cultivation are lower
than, or at best, equivalent to, yields from non-GM varieties.

Peter Melchett, Soil Association policy director, said: "GM chemical
companies constantly claim they have the answer to world hunger while
selling products which have never led to overall increases in production,
and which have sometimes decreased yields or even led to crop failures. As
oil becomes scarcer and more expensive, we need to move away from oil
dependent GM crops to producing food sustainably, using renewable energy, as
is the case with organic farming."

Latest Research on GM Crop Yields

GM crops as a whole

First generation genetic modifications address production conditions (insect
and weed control), and are in no way intended to increase the intrinsic
yield capacity of the plant.

An April 2006 report from the United States Department of Agriculture
(USDA) states that "currently available GM crops do not increase the yield
potential of a hybrid variety. [?] In fact, yield may even decrease if the
varieties used to carry the herbicide tolerant or insect-resistant genes are
not the highest yielding cultivars".
(Fernandez-Cornejo, J. and Caswell, 2006)

The United Nations Food and Agriculture Organization's 2004 report on
agricultural biotechnology acknowledges that GM crops can have reduced
yields (FAO, 2004). This is not surprising given that first-generation
genetic modifications address production conditions (insect and weed
control), and are not intended to increase the intrinsic yield capacity of
the plant.

A 2003 report published in Science stated that "in the United States and
Argentina, average yield effects [of GM crops] are negligible and in some
cases even slightly negative". (Qaim and Zilberman, 2003). This was despite
the authors being strong supporters of GM crops.

Yields of both GM and conventional varieties vary - sometimes greatly -
depending on growing conditions, such as degree of infestation with insects
or weeds, weather, region of production, etc. (European Commission, 2000)

Roundup Ready (RR) GM soya

Studies from 1999 - 2007 consistently show RR GM soya to yield 4 - 12% lower
than conventional varieties.

A 2007 study by Kansas State University agronomist Dr. Barney Gordon
suggests that Roundup Ready soya continues to suffer from a yield drag: RR
soya yielded 9% less than a close conventional relative.

A carefully controlled study by University of Nebraska agronomists found
that RR soya varieties yielded 6% less than their closest conventional
relatives, and 11% less than high yielding conventional lines (Elmore et al,
2001). This 6% 'yield drag' was attributed to genetic modification, and
corresponds to a substantial loss in production of 202 kg/ha.

In 1998 several universities carried out a study demonstrating that, on
average, RR soy varieties were 4% lower in yield than conventional varieties
(Oplinger et al., 1999). These results clearly refuted Monsanto's claim to
the contrary (Gianessi, 2000).

Yields of GM soybeans are especially low under drought conditions. Due to
pleiotropic effects (stems splitting under high temperatures and water
stress), GM soybeans suffer 25% higher losses than conventional soybeans(
Altieri and Pengue, 2005)

5 studies between 2001-2007 show that glyphosate applied to Roundup Ready
soybeans inhibits the uptake of important nutrients essential to plant
health and performance. The resultant mineral deficiencies have been
implicated in various problems, from increased disease susceptibility to
inhibition of photosynthesis. Thus, the same factors implicated in the GM
soya yield drag may also be responsible for increased susceptibility to
disease. (Motavalli, et al., 2004; Neumann et al., 2006; King, et al.,2001;
Bernards,M.L, 2005; Gordon, B., 2007).
The yield drag of RR soya is reflected in flat overall soybean yields from
1995 to 2003, the very years in which GM soya adoption went from nil to 81%
of U.S. soybean acreage. By one estimate, stagnating soybean yields in the U
S. cost soybean farmers $1.28 billion in lost revenues from1995 to 2003 (Ron
Eliason, 2004). More recent evidence shows that the kilogram per hectare
ratio of soybean has been in decline since 2002, leading to the conclusion
that RR soy does not have an impact on yield (ABIOVE, 2006a).

Bt Maize

Only maize shows a persistent trend of yield increase into the biotech era,
but even here the rate of increase is no greater after than before biotech
varieties were introduced.

A rigorous, independent study conducted in the U.S. under controlled
conditions demonstrated that Bt maize yields anywhere from 12% less to the
same as near-isoline (highly similar) conventional varieties
(Ma & Subedi, 2005).

Bt Cotton

Despite claims of increased yield, Bt cotton has had no significant impact
in real terms.

Average cotton yields have increased 5-fold since 1930, and staged an
impressive surge from1980 to the early 1990s. Cotton yields then went flat,
and continued to stagnate during the seven years of GM cotton's rise to
dominance. The steep yield and production increases in 2004 and 2005 were
chiefly attributable to excellent weather conditions
(Meyer et al., 2007).

Bt cotton, introduced to Australia in 1996, has not offered a boost to the
cotton sector, and since its adoption has not provided improvements in
either yield, or quality (ISAAA, 2006b).

Cotton South Africa show constant yield levels before and after adoption of
Bt cotton (Witt et al 2005, cited in FoEI Who Benefits 2007), in
contradiction to ISAAA claims that Bt has brought about a 24% yield increase
in the region.
Outbreaks of the secondary pests that are not killed by the Bt insecticide
have rendered Bt cotton ineffective in China (Connor, S., July 27, 2006),
and are also becoming a problem in North Carolina (Caldwell, D. 2002) and
Georgia (Hollis, P.L., 2006).

An article in Nature Biotechnology notes that the poor performance of Bt
cotton varieties used in India (which were developed for the short U.S.
growing season) is linked to the loss of their insecticidal properties late
in India's longer growing season, and because Bt cotton insecticide is not
expressed in 25% of the cotton bolls of India's preferred hybrid cotton
varieties (Jayaraman, K.S., 2005)

During the Government's 2003 'national debate' on whether or not to allow
commercial planting of GM crops, the Royal Institute of Chartered Surveyors,
which represents land agents amongst others, predicted 'long-term chaos' and
possible declines in land values if GM crops were planted. [1] Recent
research in Sweden has confirmed that GM seeds can remain active in farmland
for at least 10-years, adding scientific support to the RICS's concern about
the impact on land values of growing GM crops.

Ends

For media enquiries please contact Clio Turton, Soil Association senior
press officer, 0117 914 2448 / [EMAIL PROTECTED]


References:

ABIOVE, 2006a. Sustainaibility in the Legal Amazon. Presentation by Carlo
Lovatelli at the Second Roundtable on Responsible Soy. Paraguay, 1 September
2006. http://www.abiove.com
br/english/palestras/abiove_pal_sustent_amazonialegal_us.pdf

Altieri, M., Pengue, W., 2005. GM Soya Disaster in Latin America: Hunger,
Deforestation and Socio-ecological Devastation.

Bernards, M.L. et al, 2005. Glyphosate interaction with manganese in tank
mixtures and its effect on glyphosate absorption and translocation. Weed
Science 53: 787-794.

Caldwell, D. 2002. A Cotton Conundrum. Perspectives OnLine: The Magazine of
the College of Agriculture and Life Sciences, North Carolina State
University,Winter 2002. http://www.cals.ncsu
edu/agcomm/magazine/winter02/cotton.htm

Connor, S., July 27, 2006. Farmers use as much pesticide with GM crops, US
study finds. The Independent. http://news.independent.co
uk/environment/article1199339.ece

Elmore et al, 2001. Glyphosate-Resistant Soybean Cultivar Yields Compared
with Sister Lines, Agron J 2001 93: 408-412, quote from the University of
Nebraska press release online at http://ianrnews.unl.edu/static/0005161
shtml

European Commission, 2000. Economic Impacts of Genetically Modified Crops on
theAgri-food Sector. http://europa.eu.int/comm/agriculture/publi/gmo/cover
htm

FAO, 2004. The State of World Food and Agriculture 2004. Biotechnology:
Meeting the Needs of the Poor? http://www.fao
org/newsroom/en/focus/2004/41655/

Fernandez-Cornejo, J. & Caswell. April 2006. Genetically Engineered Crops in
the UnitedStates. USDA/ERS Economic Information Bulletin n.
11. http://www.ers.usda.gov/publications/eib11/eib11.pdf

FoEI, January 2007. Who Benefits from GM crops? An analysis of the global
performance of GM crops (1996-2006)

Gianessi, L.P., April 2000. Agriculture Biotechnology: Benefits of
Transgenic Soybeans. National Center for Food and Agricultural Policy, p. 63
http://www.ncfap.org/reports/biotech/rrsoybeanbenefits.pdf

Gordon, B., 2007. Manganese nutrition of glyphosate-resistant and
conventional soybeans. Better Crops, Vol. 91, No. 4: 12-13

Hollis, P.L., February 15 2006. Why plant cotton's new genetics? Southeast
Farm Press. http://southeastfarmpress.com/mag/farming_why_plant_cottons/

ISAAA, 2006b. GM crops: the first ten years- Global Socio-Economic and
Environmental impacts. http://www.isaaa
org/resources/publications/briefs/36/download/isaaa-brief-
36-2006.pdf

Jayaraman, K.S., November 2005. Monsanto's Bollgard potentially compromised
in India. Nature Biotechnology.

King, A.C., L.C. Purcell and E.D. Vories, 2001. Plant growth and nitrogenase
activity of glyphosate-tolerant soybean in response to foliar glyphosate
applications. Agronomy Journal 93:179-186.

Ma & Subedi, 2005. "Development, yield, grain moisture and nitrogen uptake
of Bt corn hybrids and their conventional near-isolines," Field Crops
Research 93 (2-3): 199-211, at http://www.sciencedirect
com/science_ob=ArticleURL&_udi=B6T6M4DRBBYB1&_user=10&_coverDate=09%2F142F200
&_rdoc=1&_fmt=&_orig=search&_sort=d&view=c&_acct=C000050221&_version=1&_urlVe
sion=0&_userid=10&m5=5299e6ebd64c6b4db4566ee6f44eced2

Meyer, L., S.MacDonald& L. Foreman,March 2007. Cotton Backgrounder. USDA
Economic Research Service Outlook Report.

Motavalli, P.P. et al., 2004. "Impact of genetically modified crops and
their management on soil microbially mediated plant nutrient transformations
" J. Environ. Qual. 33:816-824;

Neumann, G. et al., 2006. "Relevance of glyphosate transfer to non-target
plants via the rhizosphere," Journal of Plant Diseases and Protection
20:963-969.

Oplinger, E.S et al., 1999. Performance of Transgenetic Soyabeans, Northern
US. http://www.biotech-info.net/soybean_performance.pdf

Qaim, M. and Zilberman, D., 7 February 2003. "Yield Effects of Genetically
Modified Crops in Developing Countries" in Science, vol. 299, p. 900.

Ron Eliason, 2004. Stagnating National Bean Yields. 2004 Midwest Soybean
Conference, cited by Dan Sullivan, "Is Monsanto's patented Roundup Ready
gene responsible for a flattening of U.S. soybean yields," NewFarm.org,
September 28, 2004, online at http://www.newfarm
org/features/0904/soybeans/index.shtml





  • [Livingontheland] New Soil Association report shows GM crops do not yield more, Tradingpost, 04/12/2008

Archive powered by MHonArc 2.6.24.

Top of Page