Weed Control and Yield are Equal in Conventional, Reduced-, and No-Tillage Soybean (Glycine max) After 11 Years

Abstract

Field experiments were conducted from 1979 to 1989 to determine the influence of conventional, reduced, and no-tillage systems and different herbicide combinations on weed species and population, weed control, and soybean injury, population, and yield. In no-till (NT) non-treated plots, there was an abrupt shift from horseweed as the dominant early spring emerging weed to gray goldenrod in 1985. Following its initial observation, gray goldenrod became the dominant species within 2 yr, with giant foxtail as the only other species observed in these plots. Giant foxtail was the dominant weed species from 1980 to 1989 in conventional till (CT) and reduced-till (RT) plots. There also was a shift in the frequency of occurrence and in density of several broadleaf weed species during the 11-yr study. Most herbicides provided excellent control of all weeds in all tillage systems, especially those that included POST herbicides. There was little difference between glyphosate and paraquat in controlling weeds present at the time of planting in NT. PRE herbicides caused 2 to 9% soybean injury with slightly greater injury occurring in CT and RT than in NT. The POST broadleaf herbicides did not significantly increase soybean injury. There were no differences in soybean population or yield among the herbicide treatments regardless of tillage. There also was no difference in soybean population or yield in NT compared with CT when averaged over all herbicide treatments.

The biology of Canadian weeds. 130. Solidago nemoralis Ait.

“…Solidago nemoralis dominated in 7-through 11-yr-old no-till plots, but did not occur in conventionally-tilled nor reduced-till plots in southern Illinois (Kapusta and Krausz 1993). Repeated mowing for at least 2 yr effectively controlled S. nemoralis on Missouri pasture land.…”

“…Presumably, development of a tall canopy by S. nemoralis prevented other species from becoming established in subsequent years. However, the increased occurrence of Bromus tectorum L. subsequently led to decreases in S. nemoralis (Kapusta and Krausz 1993).…”

“…ha -1 ) or paraquat (0.56 kg a.i. ha -1 ) (Kapusta and Krausz 1993). Control of S. nemoralis can also be achieved through the application of fluaxifop-butyl at 3509 cc ha -1 plus clopyralid, monoethanolamine salt at rates up to 438 cc ha -1 (Anonymous G).…”

A Meta-Analysis for the Impact of Transgenic Crop Adoption on Corn and Soybean Yield

“…Therefore, the shift to post-emergent herbicides may promote no-tillage practices that can provide environmental benefits (Holland, 2004;Locke, et al, 2008;Triplett Jr. and Dick, 2008). Producers already employing no-tillage systems were more likely to adopt GR hybrids than producers using a conventional tillage system, and producers adopting GR crop varieties were more likely to shift to no-tillage than producers not adopting GR crops and using tillage (Mensah, 2007;Buhler, 1992;Kapusta and Krausz, 1993). When weeds are controlled, crop yield and net return in no-tillage systems are often equivalent or greater than corresponding conventional tillage systems (Buhler, 1992;Kapusta and Krausz, 1993).…”

“…Producers already employing no-tillage systems were more likely to adopt GR hybrids than producers using a conventional tillage system, and producers adopting GR crop varieties were more likely to shift to no-tillage than producers not adopting GR crops and using tillage (Mensah, 2007;Buhler, 1992;Kapusta and Krausz, 1993). When weeds are controlled, crop yield and net return in no-tillage systems are often equivalent or greater than corresponding conventional tillage systems (Buhler, 1992;Kapusta and Krausz, 1993). DeFelice et al, (2006) reported that the corn and soybean yield difference between no-tillage and conventional tillage practices was found to be negligible.…”