Dissipation of Bromide and Metribuzin Affected by Tillage and Crop Residue Management in Subarctic Alaska

Abstract

ABSTRACT. Prudent use of agricultural fertilizers and herbicides is paramount for sustaining or improving surface and ground water quality in Subarctic regions, but little information is available that documents the loss of chemicals from agricultural lands in the Subarctic. This study aimed to ascertain more clearly how time of application and land management practices affect the loss of bromide and metribuzin in a Subarctic soil. Potassium bromide (KBr), a surrogate for nitrate, and metribuzin, commonly used to control broadleaf weeds, were applied in the autumn of 1996 and the spring of 1997 to a silt loam that had been subjected to conventional tillage (CT), minimum tillage (disk once [DO]), and no tillage (NT) since 1983. Superimposed on the tillage treatments were the removal or retention of barley (Hordeum vulgare L.) stubble and loose straw. Loss of these chemicals was ascertained by sampling the soil profile at the time of heading of barley, before freeze-up of the soil in autumn, and after spring thaw until September 1998. Tillage and residue treatments did not influence the recovery of autumn-applied or spring-applied Br. However, recovery of Br diminished with time: about 30% of the Br applied in autumn and 45% of that applied in spring remained in the soil profile by September 1998. Tillage, but not residue, treatments influenced the recovery of metribuzin. Recovery of metribuzin at the termination of this study was 6% or more in NT soil and 2% or less in CT and DO soil; greater recovery in NT soil was presumably a result of slower degradation in NT than in CT and DO. This study suggests that bromide (and thus nitrate) and metribuzin are more prone to leaching when applied in autumn and that tillage practices affect retention of metribuzin, but not nitrate, in the soil of Subarctic Alaska.Key words: herbicide, retention, leaching, solute, nitrate RÉSUMÉ. Une utilisation prudente des engrais et des herbicides est cruciale au maintien ou à l'amélioration de la qualité de l'eau de surface et de l'eau souterraine dans les régions subarctiques, mais il existe peu de documentation sur la déperdition des produits chimiques dans le sol des terres agricoles du Subarctique. Cette étude vise à établir avec plus de précision la façon dont le moment de l'application et les pratiques de gestion des terres affectent la déperdition du bromure et de la métribuzine dans un sol subarctique. Le bromure de potassium (KBr), un substitut du nitrate, et la métribuzine, couramment utilisée pour lutter contre les dicotylédones, ont été appliqués en automne 1996 et au printemps 1997 sur un loam limoneux qui avait subi un travail du sol classique (TC), un travail minimum (un seul passage du cultivateur à disque [TM]) et aucun travail (AT) depuis 1983. On a ajouté au travail du sol le déchaumage de l'orge (Hordeum vulgare L.) ou le maintien du chaume et de la paille. On a vérifié la déperdition de ces produits chimiques jusqu'en septembre 1998 en analysant le profil pédologique au moment de l'épiaison de l'orge, avant que le so...

Effects of bromides of potassium and ammonium on some crops

“…Among selected bromides, potassium bromide was used more often for experiments on uptake of Br by plants (Berry and Steward 1934;Buwalda, Stribley and Tinker 1983;Schnabel, Stout and Shaffer 1995;Sharratt and Knight 2005). Less information is available on effects of ammonium bromide on plants (Jacoby 1965;Wetchagarun et al 2017).…”

Solute Transport in Eroded and Rehabilitated Prairie Landforms. 1. Nonreactive Solute

“…Dissipation of spring-applied bromide during the first 41 days after application translates to ∼27 kg ha -1 . Bromide mass loss of >100 kg ha -1 (20-30% of applied) from soil cropped to barley was observed between early May and early July with about half the rainfall as occurred during this study (18).…”

“…These results are similar to previous reports of winter bromide mass loss in northern climates. Bromide loss from the top 1 m between application in September and the following spring amounted to 30 kg ha -1 (5% of applied) in Subarctic Alaska (18) and 36 kg ha -1 (30% of applied) in The Netherlands (5). During the time period from November 21 to May 1 (14-175 days after fall application), the soil was frozen most of the time and there was no opportunity for plant uptake.…”

Impact of soil amendments on metribuzin and DCPA half-lives and mobility into agricultural runoff water

“…Sharratt and Knight [41] reported that metribuzin was not detected within the soil profile below a depth of 10 cm at any time. The Downloaded by [Korea University] at 12:39 26 December 2014 Fig.…”