Adsorption and Desorption of Urea Herbicides on Soils

Abstract

(May 1975) and diuron (Rhodes et al. 1970;Helling 1971)

Effects of Soil Surface Drying on Linuron Activity in Organic Soils

“…a r6duit l'action de ce produit sur la moutarde de I'lnde (Brassica juncea L.) et la tomate (L.l,'copersicum (Walker 1973;Savage 1973;Grover 1975). These studies do not provide information on the inactivation power of organic material at different moisture levels at time of application.…”

“…For tomato, significant differences were apparent only at the 1.0 and 2.0 ks/ha rates. (Grover 1975;Walker 1913 …”

Verification of the prediction technique for the amount of adsorbed linuron on soils

“…(Seybold and Mersie 1996),0.9 to 13 and l.0 to 1.2 (Francioso et al 1992), and 0.19 to 4.83 and 0.59 to 1.06 (Sonon and Schwab 1995), respectively. On the other hand, the reported values of KF and 11 n for !inuron were 6.9 to 97.7 and 0.65 to 0.77 (Grover 1975), and 28.9 to 68.4 and 0.8 to l.3 (Khan 1974b), respectively. These data indicate that a larger amount of linuron than atrazine was adsorbed on soils.…”

“…KF and 1 /11 are constants, obtained from the intercept and slope of a log-log plot of practical measurements of Wand C. Although the Freundlich isotherm is empirical, KF is indicative of the extent of adsorption, and 1 / n is the degree of nonlinearity between the solution concentration and adsorption (Grover 1975). Attempts were made to determine the physical significance of on KF and 1 / n, and it was considered that 1 / IZ was correlated with the adsorption affinity between an adsorbate and an adsorbent.…”

Relationship between Freundlich isotherm Coefficients, logKFand 1 /nfor atrazine desorption from soils in Japan

“…Herbicide desorption from as well as adsorption on soil has been studied frequently (Grover 1975;Clay et al 1988;Clay and Koskinen 1990;Ma et al 1993; Barriuso et al 1994;Gonzalez and Ukrainczyk 1996;Celis and Koskinen 1999). In most of the reports, the hysteresis of adsorption-desorption phenomena was considered, as evidence of hysteresis is critical in view of consideling the mobility of a hcrbicide in soils.…”