Influence of Tillage Method on Management ofAmaranthusSpecies in Soybean

Abstract

A field study was conducted in 2014 and 2015 in Arkansas, Illinois, Indiana, Ohio, Tennessee, Wisconsin, and Missouri to determine the effects of tillage system and herbicide program on season-long emergence of Amaranthus species in glufosinate-resistant soybean. The tillage systems evaluated were deep tillage (fall moldboard plow followed by (fb) one pass with a field cultivator in the spring), conventional tillage (fall chisel plow fb one pass with a field cultivator in the spring), minimum tillage (one pass of a vertical tillage tool in the spring), and no-tillage (PRE application of paraquat). Each tillage system also received one of two herbicide programs; PRE application of flumioxazin (0.09 kg ai ha ). The deep tillage system resulted in a 62, 67, and 73% reduction in Amaranthus emergence when compared to the conventional, minimum, and no-tillage systems, respectively. The residual herbicide program also resulted in an 87% reduction in Amaranthus species emergence compared to the POST-only program. The deep tillage system, combined with the residual program, resulted in a 97% reduction in Amaranthus species emergence when compared to the minimum tillage system combined with the POST-only program, which had the highest Amaranthus emergence. Soil cores taken prior to planting and herbicide application revealed that only 28% of the Amaranthus seed in the deep tillage system was placed within the top 5-cm of the soil profile compared to 79, 81, and 77% in the conventional, minimum, and no-tillage systems. Overall, the use of deep tillage with a residual herbicide program provided the greatest reduction in Amaranthus species emergence, thus providing a useful tool in managing herbicide-resistant Amaranthus species where appropriate. Nomenclature: Flumioxazin; glufosinate; metolachlor; paraquat; Amaranthus; soybean, Glycine max (L.) Merr. Key words: moldboard plow, vertical tillage, seedbank, soil-applied residual.En 2014 y 2015, se realizó un estudio de campo en Arkansas, Illinois, Indiana, Ohio, Tennessee, Wisconsin, y Missouri para determinar los efectos del sistema de labranza y el programa de herbicidas sobre la emergencia de especies de Amaranthus a lo largo de la temporada de crecimiento en soja resistente a glufosinate. Los sistemas de labranza evaluados fueron labranza profunda (arado de vertedera en el otoño seguido por (fb) un pase de cultivador de campo en la primavera), labranza convencional (arado de cincel en el otoño seguido de un pase de cultivador de campo en la primavera), labranza mínima (un pase de una herramienta de labranza vertical en la primavera), y cero labranza (aplicación PRE de paraquat). Cada sistema de labranza también recibió uno de dos programas de herbicidas; aplicación PRE de flumioxazin (0.09 kg ai ha ). El sistema de labranza profunda resultó en una reducción de 62, 67, y 73% en la emergencia de Amaranthus cuando se comparó con los sistemas de labranza convencional, mínima, y cero, respectivamente. El programa con un herbicida residual también resultó en una reducción de 87...

No-tillage altered weed species dynamics in a long-term (36-year) grain sorghum experiment in southeast Texas

“…Shifting from CT to conservation tillage can influence weed population dynamics by altering the vertical distribution of weed seeds in soil and impacting weed seedbank persistence and seedling recruitment (Farmer et al 2017;Young and Thorne 2004). The lack of soil inversion in conservation-tillage systems may lead to the accumulation of weed seeds in the topsoil layer, thus altering their distribution in the soil profile.…”

Changes in weed seed bank and flora as affected by soil tillage systems

“…Tillage is an important aspect of farm management. Non-inversion or minimum tillage reduces energy usage, enables faster soil preparation and improves soil aggregation (Vakali et al, 2011;Bottineli et al, 2017), but deep-tillage implements that invert soil layers, bury weed seeds deep enough to prevent their germination and emergence (Farmer et al, 2017). In some cases, integrated use of mouldboard plough reduced the emergence of weeds by at least 95% over two growing seasons (Bagavathiannan, Norsworthy, 2012).…”

Thirty‐six years of no‐tillage regime altered weed population dynamics in soybean

“…Clements et al (1996) reported that more than 70% of the total weed seeds were observed near the soil surface in the NT system compared to only 37% of seeds in the CT system. Farmer et al (2017) also reported that 91% of seeds of Amaranthus species were located in the 0-to 5-cm depth in the NT system compared to 71% in the CT system. The occurrence of seeds beyond 15-cm depth in NT could be likely due to movement of seeds through soil cracks and short distance movement of seed through ingestion and excretion by earthworms (Hurka & Haase, 1982).…”

“…Steckel et al (2007) observed that the density of waterhemp (Amaranthus rudis Sauer), a small-seeded broadleaf weed, was more (3,940 plants m -2 ) in the NT system compared to a field under chisel plowing (2,100 plants m -2 ). Likewise, Farmer et al (2017) reported 28% greater Palmer amaranth (A. palmeri S. Watson) density in NT than in CT systems.…”