Adsorption and degradation of imazapic in soils under different environmental conditions

Abstract

Imazapic is widely used in peanut production, and its residues can cause damage to succeeding crops planted in the following year. The planting area of peanut is large in Henan province. Inceptisol is the main soil type in Henan Province and was used in laboratory experiments that were conducted to investigate imazapic degradation in soil under various environmental conditions. The results indicated that the imazapic degradation rate increased with an increase in temperature, soil pH, and soil moisture, and decreased with organic matter content. The use of biogas slurry as a soil amendment accelerated imazapic degradation. The half-life of imazapic in sterilized soil (364.7 d) was longer than in unsterilized soil (138.6 d), which suggested that there was a significant microbial contribution to imazapic degradation. Imazapic adsorption was also examined and was found to be well described by the Freundlich isotherm. The results indicate that soil has a certain adsorption capacity for imazapic.

Field measurement and modelling of chlorotoluron and flufenacet persistence in unamended and amended soils

“…The lower dissipation rate of chlorotoluron in S+SMS soil can be explained by the decrease in its leaching through the soil profile because of higher adsorption: K d values as determined by Carpio et al (2020) were 0.773 L kg -1 in S soil and 4.773 L kg -1 in S+SMS (Table S5). High adsorption of chlorotoluron by amended soils leads to a decrease in the bioavailability of the herbicide to be degraded, as reported previously for this herbicide (Kodešová et al, 2012; and for other compounds Su et al, 2019). On the contrary, Rodríguez-Liébana et al ( 2014) found a rapid dissipation of chlorotoluron (DT 50 = 2.4 days) in a field amended soil.…”

“…It is due to abiotic and biotic degradation, loss by volatilization, plant uptake, runoff and/or leaching. Herbicides dissipation in amended soils has been widely studied under laboratory conditions (Barba et al, 2019;Cassigneul et al, 2018;Su et al, 2019). On the contrary, herbicides persistence and dissipation in amended soils have been scarcely studied under field conditions (Cañero et al, 2012;García-Delgado et al, 2019).…”

Imidazolinone herbicide dissipation in rice fields as affected by intermittent and continuous irrigation

“…The main factor responsible for the dissipation of IMI in the field is microbial degradation (Kraemer et al, 2009;Su et al, 2019). The diversity of microorganisms in the soil is vast; therefore, several soil microorganisms can degrade these herbicides.…”

“…Therefore, several factors may affect IMI sorption, including soil pH. In low soil pH, these molecules interact strongly with soil particles, slowing the dissipation processes (Gehrke et al, 2021;Su et al, 2019). This fact is due to the amphoteric behavior of IMI, which allows these herbicides to act as weak acids or bases, depending on the pH of the environment in which they are present (Gianelli et al, 2014).…”

Effect of Organic Residues on Pesticide Behavior in Soils: A Review of Laboratory Research

“…The impact on pesticide degradation of other organic amendments applied to soils has been investigated for the herbicide imazapic under various environmental conditions, including temperature, soil moisture, and soil pH [159]. CM and biogas slurry (BS) have been applied at different rates, and herbicide degradation has been studied at different temperatures (15, 25 and 35 • C), soil moisture content (15%, 40%, 60% and 90%), and soil pH (6.0, 7.0 and 8.0).…”