The main premise appeared to be supported by entries such as this at Potash Corp in 2007:
Manganese Response of Conventional and Glyphosate-Resistant Soybean
Project Leader: Dr. Nathan Nelson, Kansas State University, Agonomy, 2708 Throckmorton Plant Sciences Center, Manhattan, KS 66506-5501.
Telephone: (785) 532-5115. Fax: (785) 532-6094.
Weed control benefits of glyphosate resistant (GR) soybeans have resulted in nearly complete adoption of GR soybean varieties by U.S. producers, despite an apparent yield decrease that accompanies this decision. Although the reasons for the yield decrease are not known, there is some evidence that GR soybeans have reduced manganese (Mn) uptake compared to conventional soybeans. Therefore, Mn additions may help overcome the apparent yield disadvantage of GR soybeans. The objectives of this study are to: i) evaluate nutrient uptake, distribution, and biomass accumulation in a GR soybean cultivar compared to a non-GR sister line, and ii) determine the response of a GR and non-GR soybean cultivar to soil and foliar Mn applications. Field plots were established at five locations (Scandia, Manhattan, Ashland Bottoms, Rossville, and Ottawa) in North Central and Eastern Kansas in 2006 and 2007 to compare conventional and GR soybean response to three rates of soil applied and two rates of foliar Mn. Response variables include yield, biomass, plant height, Mn uptake, and leaf, and grain Mn concentrations.
Application of Mn increased GR soybean yields between 6 and 14 bu/A at the Scandia site, but results were inconsistent at the other sites. Conventional soybeans were not responsive to Mn at any of the locations in 2006, but were responsive at the Scandia site in 2007. Over all, soybean yields were greater at the Scandia location compared to the other locations for both years, suggesting that the yield increase from Mn application to GR soybeans may only occur in high yielding environments (>60 bu/A). Trends indicated a yield response to both soil-applied and foliar-applied Mn, but the results were inconsistent across locations. Preliminary plant analyses show that there was no significant difference in Mn uptake between the GR and non-GR varieties. There were some differences in nutrient partitioning, where the non-GR soybeans had more K remaining in the leaves at R6 growth stage. Further analysis of 2007 data will be conducted to confirm these observations.
The premise appeared to also be supported by one of the other studies cited in The Independent article which concluded:
3 comments:
So, Monsanto's Roundup-resistant soybeans produce less than the other kind, but they will produce more if the farmers put manganese on them, which increases their costs farther down the road. Have I got that right?
But I'm still a little vague on the connection with Potash Corp. of Saskatchewan.
Potash Corp online published a report which supported the claim that GM soya bean crops yeilds are less than non-GM soya.
It was used as a reference source.
Ok. Thanks for clearing that up.
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