Degradation Process of Herbicides in Biochar-Amended Soils: Impact on Persistence and Remediation

Abstract

Biochar is a solid material derived from different feedstocks that is added to the soil for various agronomic and environmental purposes, such as nutrient sources and CO2 emission mitigators. In modern agriculture, the application of herbicides directly in the soil is common for pre-emergent weed control; however, biochars may interfere in the degradation processes of these agrochemicals, increasing or decreasing their persistence. Long persistence is desirable for some herbicides in determined cultivation systems, especially in monoculture, but persistence is undesirable in crop rotation and/or succession systems because the subsequent cropping can be sensitive to the herbicide, causing carryover problems. Therefore, knowing the interactions of biochar-herbicide is essential, since these interactions depend on feedstock, pyrolysis conditions (production temperature), application rate, biochar aging, among other factors; and the physical-chemical characteristics of the herbicide. This chapter shows that the addition of biochar in the soil interferes in the persistence or remediation processes of the herbicide, and taking advantage of the agricultural and environmental benefits of biochars without compromising weed control requires a broad knowledge of the characteristics of biochar, soil, and herbicide and their interactions.

Emerging contaminants: A One Health perspective

“… 533 Biochar, recognized as an environmentally friendly material, not only plays a pivotal role in alleviating soil contamination but also enhances the properties of degraded soil, serving as an ideal habitat for beneficial microbes. 534 , 535 Ultrasonic waves are effective in destroying the structure of algae cells through the mechanical vibration effect. 536 Additionally, physical methods such as manual salvage or mechanical algae removal equipment can be used to prevent the accumulation of cyanobacteria.…”

Pyrolysis Temperature vs. Application Rate of Biochar Amendments: Impacts on Soil Microbiota and Metribuzin Degradation

“…Herbicides are used for weed control in pre- or post-emergence, and regardless of the mode of application, they can reach the soil and persist with a residual effect for weed control and cause carryover problems in succeeding crops or contaminate non-target organisms and the environment [ 1 ]. The negative impacts of herbicide residues can be categorized based on the chemical structure of the herbicides, crop species, environmental conditions, and soil properties.…”

“…Biochar-amended soils can directly influence the degradation half-life time (DT 50 ) of herbicide depending on the molecule, pyrolysis temperature, application rate, and feedstock used [ 1 ]. For example, the total amount of hexazinone (mineralized residue + non-extracted or bound residue) in soils amended with biochar from eucalyptus wood waste produced at pyrolysis temperatures of BC850 °C (46%) and BC950 °C (49%) was higher compared to biochar produced at BC650 °C (33%) and BC750 °C (42%) [ 14 ].…”

Comportamento de herbicidas pré-emergentes em palhadas de diferentes plantas de cobertura

“…Em termos gerais, a retenção possui relação inversamente proporcional ao processo de transporte e direta com a persistência do herbicida no solo (Lehmann et al, 1992;Guo et al, 2000;Silva et al, 2022;Mielke et al, 2022). Dessa maneira, herbicidas que apresentam alta sorção no solo são menos lixiviados e degradados.…”