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ARS Home » Research » Publications at this Location » Publication #168249
Title: METHOD AND TIMING OF RYE CONTROL AFFECTS SOYBEAN DEVELOPMENT AND RESOURCE UTILIZATION

Author
item WESTGATE, LESLIE - IA STATE UNIVERSITY
item Singer, Jeremy
item Kohler, Keith

Submitted to: Agronomy Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/1/2004
Publication Date: 4/27/2005
Citation: Westgate, L.R., Singer, J.W., Kohler, K.A. 2005. Method and timing of rye control affects soybean development and resource utilization. Agronomy Journal. 97:806-816.

Interpretive Summary: Cover crops provide environmental and soil quality benefits, yet their adoption into production agriculture has been limited. This study was conducted to determine whether differences exist in soybean water use, light interception, weed suppression, and development following a rye cover crop to provide management information that may increase rye cover crop adoption. The effects of mechanical and chemical rye control at different growth stages was investigated near Boone, IA in 2002 and 2003. Regrowth from mechanical rye control in 2002 depleted soil water until rye matured. Light interception by soybean was reduced when rye was controlled early because of rye regrowth or weed competition. Soybean dry matter was greater when rye was chemically versus mecahnically controlled in one year and similar in the other. However, almost all treatments with rye had lower dry matter accumulation than the control. Rye delayed pod maturity in both years compared to the control. Soybean producers who adopt these methods of rye management can expect delayed soybean maturity and reduced dry matter accumulation.

Technical Abstract: Cover crops provide environmental and soil quality benefits, yet their adoption into production agriculture has been limited. This study was conducted to determine whether differences exist in soybean [Glycine max (L.) Merr.] resource utilization and development following a rye (Secale cereale L.) cover crop. The effects of mechanical and chemical rye control at 2nd node, boot, and anthesis on soil water, light interception, weed suppression, and soybean growth were investigated near Boone, IA in 2002 and 2003. Regrowth from mechanical rye control in 2002 depleted soil water until rye matured. At day of year (DOY) 226 and 230 in 2002 and 2003, light interception by soybean was 51, 72, 91, and 94% and 67, 75, 94, and 97% in chemical and 45, 53, 52, and 96% and 72, 70, 73, and 95% in mechanical control for 2nd node, boot, anthesis, and control treatments. At DOY 241 in 2002, chemical control accumulated 695, 692, 840, and 962 compared to 219, 328, 325, and 1126 g m-2 dry matter in mechanical control for 2nd node, boot, anthesis, and control treatments. At DOY 239 in 2003, 2nd node, boot, anthesis, and the control accumulated 395, 443, 380, and 637 g m-2 dry matter. Rye delayed pod maturity in 2002 by 6.3, 6.8, and 6.3 d in chemical and 8.3, 7.0, and 6.8 d in mechanical control for 2nd node, boot, and anthesis treatments compared to the control and by 5.3, 5.0, and 3.8 d in 2003. Producers who adopt these methods of rye management can expect delayed soybean maturity and reduced dry matter accumulation.