Soil Degradation of Three Dinitroanilines

Abstract

These studies were conducted in the laboratory on two soils at two temperatures to define the rate of degradation and the associated rate law for trifluralin (α,α,α-trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine), benefin (N-butyl-N-ethyl-α,α,α-trifluoro-2,6-dinitro-p-toluidine), and 2,6-dinitro-N-(3-pentyl)-α,α,α-trifluoro-p-toluidine (hereafter referred to as Unnamed). Rate of degradation was directly correlated with temperature and moisture content. First order kinetics adequately described the rate of degradation at 15 C, but the simple first order assumption was not sufficient to describe degradation at 30 C. The implication of our interpretation is that at 30 C two rate processes may operate in the soil degradation of these three dinitroaniline herbicides. The data show an initial rapid first order rate of degradation with a subsequent change to a slower first order process. First half lives ranged from 0.4 to 1.8 months at 30 C and were consistently lower in a loam than in a sandy loam soil.

Dissipation of Pendimethalin in Organic Soils in Florida

“…Similarly, Barrett and Lavy (1983) reported rapid pendimethalin dissipation during the first 14 d after application. The initial rapid dissipation of other soil applied dinitroanilines has been previously reported (Poku and Zimdahl 1980;Serrano et al 2010;Zimdahl and Gwynn 1977). The rapidly dissipated fraction of pendimethalin does not contribute greatly to weed control; therefore, it is the second phase of dissipation that is important for weed management (Shaner 2012).…”

Simultaneous gas-liquid chromatographic analysis of trifluralin and benfluralin residues in turfgrass thatch and soil by solid-phase extraction technique

“…Turfgrass thatch is a tightly intermingled layer of living and dead stems, leaves and roots of grass that develops between vegetation and the soil surface (Beard, 1973 The final detection of trifluralin and benfluralin has been made with ECD (Tepe and Scroggs, 1967, Zimdahl and Gwynn, 1977, Day, 1978 T I ' It has been demonstrated before Niemczyk, 1990a, 1990) that solid-phase extraction/purif- …”

“…The existing residue methodologies (Tepe and Scroggs, 1967, zimdahl and Gwynn, 1977, Day, 1978 The technique presented in this paper combines the use of solid-phase extraction/purification and megabore, fused silica column gas chromatography with NP detection for either simultaneous or separate analysis of trifluralin and benfluralin residues in turfgrass thatch and soil. …”

Bioactivity, adsorption and persistence of pretilachlor in paddy field soils

“…The direct relationship between soil Downloaded by [Erciyes University] at 14:14 27 December 2014 temperature and degradation is well established (Zimdahl and Gwynn, 1977;Zimdahl and Clark, 1982;Ismail and Teoh, 1994). We also found that the degradation rate of pretilachlor was the highest at 35 C C for the three soil types studied.…”