Low Sorption and Fast Dissipation of the Herbicide Saflufenacil in Surface Soils and Subsoils of an Eroded Prairie Landscape

Abstract

Saflufenacil partitioning and dissipation were evaluated in soils from an eroded prairie landscape to provide information on its expected environmental fate. Saflufenacil K(d) values followed trends in soil organic carbon content. In surface soils, K(d) values ranged from 0.05 to 0.2 L kg(-1) in the depositional lower slope and from 0.02 to 0.06 L kg(-1) in the eroded upper slope. In subsurface soils, K(d) values were an order of magnitude higher in the lower slope (mean 0.1 L kg(-1)) than in the upper slope (mean 0.01 L kg(-1)). Sorption was slightly higher in samples aged 1-8 weeks compared to freshly spiked soils. Mean dissipation half-lives (DT(50)) were 13 d in surface soils and 32 d in subsurface soils. The observed low sorption and relatively rapid dissipation of saflufenacil suggest that this herbicide will be readily available for degradation or plant uptake in the root zone.

Selectivity of Saflufenacil Applied Singly and in Combination With Glyphosate on Coffee and Citrus Crops

“…Low sorption of this herbicide in soils with clayey and medium texture has been observed. A positive correlation has been observed between the saflufenacil sorption and the increase in organic carbon content in the soil (PAPIERNIK et al, 2012;MATALLO et al, 2014).…”

“…g dm Papiernik et al (2012); Matallo et al (2014) reported that saflufenacil has a low sorption coefficient in medium textured soils, thus, it may be available in the root zone for uptake by plants. Therefore, a sandy soil was used in this study to ensure that the herbicide became available in the root zone for uptake by the plants.…”

“…Glyphosate has a high adsorption capacity in the soil (CHEAH et al, 1997), on the other hand, studies suggest that the saflufenacil in the root zone is readily available in the soil solution for leaching, degradation or plant uptake (MONQUERO et al, 2012;PAPIERNIK et al, 2012;MATALLO et al, 2014).…”

Saflufenacil and indaziflam herbicide effects on agricultural crops and microorganisms

“…According to Papiernik et al (2012), the half-life of saflufenacil ranges from 13 (in the arable layer) to 32 days (in the subsurface layer), with low soil sorption and rapid dissipation. However, injuries were observed in rotational crops (pumpkin, cucumber, carrots, garlic, pepper and beet) up to one year after high herbicide doses (100 to 200 g a.i.…”

Would banning atrazine benefit farmers?

“…18 As a result, this highly effective herbicide was likely to have been nearly ignored in Bridges' calculations. Moreover, the yield loss estimates from Bridges that are used throughout the ABT economic calculations are based entirely on a one-for-one substitution of a single alternative herbicide treatment for atrazine.…”