Propisochlor retention and mobility in the presence of straw in Brazilian cropping systems

ABSTRACT

Non-ionic herbicides, such as propisochlor, are more easily retained in organic soil fractions. The presence of straw in tropical cropping systems can affect herbicide transposition to the underlying seed banks and their environmental behavior. The aim of this study was to evaluate propisochlor soil retention in the presence of soybean and sugarcane straw (0, 5 and 10 t ha⁻¹) through radiometric techniques. Most of the applied ¹⁴C-propisochlor was retained in the soil profile (18.2–39.4%) following an extreme rainfall simulation in the presence of straw. Decreased herbicide leaching was observed in the presence of sugarcane and soybean straw (0.7–0.5%), compared with soil without straw (1.8%). Hysteresis values ranged from 0.8 to 1.0, indicating that propisochlor sorption was reversible allowing for soil seed bank effects, as well as environmental dissipation. These findings indicate that propisochlor can overcome straw barriers, although representing low groundwater contamination risks. Because of this, reduced environmental impacts following the application of this herbicide are noted for tropical cropping systems containing straw mulch.

KEYWORDS:

• Non-ionic herbicide
• pre-emergent
• straw
• sorption-desorption
• leaching

Acknowledgements

The authors thank the Center for Nuclear Energy in Agriculture (CENA/USP) for providing the laboratory and facilities where this study was performed. And the São Paulo Research Foundation (FAPESP) for the financial support. The authors also thank the UPL do Brasil for the ¹⁴C-propisochlor supplied.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Author contribution

N. S. Pereira: Conceptualization, Investigation, Methodology, Writing - original draft.

G. V. Munhoz-Garcia: Methodology, Writing - original draft.

V. Takeshita: Conceptualization, Investigation, Methodology, Writing - review & editing, Supervision.

R. F. Pimpinato: Investigation, Methodology.

V. L. Tornisielo: Conceptualization, Supervision.

All authors revised the final version of the manuscript.

Data available

The datasets used and/or analyzed during the current study are available from the corresponding author on reasonable request.

Supplementary material

Supplemental data for this article can be accessed online at https://doi.org/10.1080/03650340.2022.2103674

Additional information

Funding

This work was supported by São Paulo Research Foundation (FAPESP, Process: 2019/04758-1 and 2020/12644-3).