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Seeding Rate Effects on Weed Control and Yield For Organic Soybean Production

Published online by Cambridge University Press:  20 January 2017

George T. Place ,
Samuel Chris Reberg-Horton ,
Jim E. Dunphy  and
Adam N. Smith
George T. Place
Affiliation:
Department of Crop Science, North Carolina State University, Raleigh, NC 27695. Study conducted in 2006 and 2007
Samuel Chris Reberg-Horton*
Affiliation:
Department of Crop Science, North Carolina State University, Raleigh, NC 27695. Study conducted in 2006 and 2007
Jim E. Dunphy
Affiliation:
Department of Crop Science, North Carolina State University, Raleigh, NC 27695. Study conducted in 2006 and 2007
Adam N. Smith
Affiliation:
Department of Crop Science, North Carolina State University, Raleigh, NC 27695. Study conducted in 2006 and 2007
*
Corresponding author's E-mail: chris_reberg-horton@ncsu.edu.
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Abstract

The organic grain sector is one of the fastest growing sectors of the organic market, but farmers in the mid-Atlantic cannot meet the organic grain demand, including the demand for organic soybean. Weed management is cited by farmers as the largest challenge to organic soybean production. Recent soybean population studies show that lower seeding rates for genetically modified organism soybean farmers provide maximum economic return due to high seed technology fees and inexpensive herbicides. Such economic analysis may not be appropriate for organic soybean producers due to the absence of seed technology fees, stronger weed pressures, and price premiums for organic soybean. Soybean seeding rates in North Carolina have traditionally been suggested at approximately 247,000 live seeds/ha, depending on planting conditions. Higher seeding rates may result in a more competitive soybean population and better economic returns for organic soybean producers. Experiments were conducted in 2006 and 2007 to investigate seeding rates of 185,000, 309,000, 432,000, and 556,000 live seeds/ha. All rates were planted on 76-cm row spacing in organic and conventional weed management systems. Increased soybean seeding rates reduced weed ratings at three of the five sites. Increased soybean seeding rates also resulted in higher yield at three of the four sites. Maximum economic returns for organic treatments were achieved with the highest seeding rate in all sites. Results suggest that seeding rates as high as 556,000 live seeds/ha may provide organic soybean producers with better weed control, higher yield, and increased profits.

Keywords

SoybeanGlycine max (L.) MerrAlternative weed managementcultural weed controlorganic grain production
Type
Research Article
Information
Weed Technology , Volume 23 , Issue 4 , December 2009 , pp. 497 - 502
Copyright
Copyright © Weed Science Society of America 

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References

Literature Cited

Ablett, G. R., Beversdorf, W. D., and Dirks, V. A. 1991. Row width and seeding rate performance of indeterminate, semideterminate, and determinate soybean. J. Prod. Agric 4:391–395.CrossRefGoogle Scholar
Archer, D. W., Jaradat, A. A., Johnson, J. M. F., Weyers, S. L., Gesch, R. W., Forcella, F., and Kludze, H. K. 2007. Crop productivity and economics during the transition to alternative cropping systems. Agron. J. 99:1538–1547.Google Scholar
Bertram, M. G. and Pedersen, P. 2004. Adjusting management practices using glyphosate-resistant soybean cultivars. Agron. J. 96:462–468.Google Scholar
Burnside, O. C. and Moomaw, R. S. 1977. Control of weeds in narrow-row soybeans. Agron. J. 69:793–796.Google Scholar
Draper, N. R. and Smith, H. 1981. Applied Regression Analysis. New York: Wiley. 33–42, 511.Google Scholar
Garrett, K. A. and Dixon, P. M. 1998. When does the spatial pattern of weeds matter? predictions from neighborhood models. Ecol. Appl 8:1250.Google Scholar
Hamilton, M., Burton, M., Weisz, R., and York, A. 2007. North Carolina Organic Grain Production Guide. North Carolina State University. http://www.cefs.ncsu.edu/PDFs/organicgrainfinal.pdf. Accessed July 30, 2008.Google Scholar
Hamilton, M. and Rzewnicki, P. 2007. North Carolina Organic Grain Production Guide. North Carolina State University. http://www.cefs.ncsu.edu/PDFs/organicgrainfinal.pdf. Accessed July 30, 2008.Google Scholar
Harder, D. B., Sprague, C. L., and Renner, K. A. 2007. Effect of soybean row width and population on weed, crop yield, and economic return. Weed Technol 21:744–752.Google Scholar
Légère, A. and Schreiber, M. M. 1989. Competition and canopy architecture as affected by soybean (Glycine max) row width and density of redroot pigweed (Amaranthus retroflexus). Weed Sci 37:84–92.Google Scholar
Liebman, M. and Gallandt, E. 1997. Many little hammers: ecological approaches for management of crop-weed interactions. Pages 78. in Jackson, L. E. Agricultural Ecology. San Diego: Academic.Google Scholar
Nice, G. R. W., Buehring, N. W., and Shaw, D. R. 2001. Sicklepod (Senna obtusifolia) response to shading, soybean (Glycine max) row spacing, and population in three management systems. Weed Technol 15:155–162.CrossRefGoogle Scholar
Norsworthy, J. K. and Oliver, L. R. 2001. Effect of seeding rate of drilled glyphosate-resistant soybean (Glycine max) on seed yield and gross profit margin. Weed Technol 15:284–292.Google Scholar
Paulson, A. 2006. As ‘organic’ goes mainstream, will standards suffer?. Christian Science Monitor. May 17, 2006. http://www.csmonitor.com/2006/0517/p13s01-lifo.html. Accessed August 28, 2009.Google Scholar
Reddy, K. N. 2002. Weed control and economic comparisons in soybean planting systems. J. Sustain. Agric 21 (2):21–35.Google Scholar
Rich, A. M. and Renner, K. A. 2007. Row spacing and seeding rate effects on Eastern Black Nightshade (Solanum ptycanthum) and soybean. Weed Technol 21:124–130.Google Scholar
USDA Economic Research Service 2008. http://www.ers.usda.gov/Data/Organic/. Accessed March 23, 2008.Google Scholar
Vangessel, M. J., Schweizer, E. E., Lybecker, D. W., and Westra, P. 1995. Compatibility and efficiency of in-row cultivation for weed management in corn (Zea mays). Weed Technol 9:754–760.Google Scholar
Walz, E. 1999. Third Biennial National Organic Farmers' Survey. Santa Cruz, CA: Organic Farming Research Foundation. 19–47.Google Scholar
Wiese, A. F., Collier, J. F., Clark, L. E., and Havelka, U. D. 1964. Effects of weeds and cultural practices on sorghum yield. Weeds 12:209–211.Google Scholar