Beatriz Gámiz

• PhD
• Assistant Professor at University of Córdoba

[This corrects the article DOI: 10.1371/journal.pone.0291398.].

The use of natural plant growth regulators (PGRs) as ecofriendly agrochemicals is gaining much attention, but the fate of these compounds once they enter the soil environment is poorly understood. In this work, we compared the plant growth inhibitory activity of the phytohormone S-abscisic acid (S-ABA) in the presence of three soils with that obser...

2-Methyl-4-chlorophenoxyacetic acid (MCPA) is a highly mobile herbicide that is frequently detected in global potable water sources. One potential mitigation strategy is the sorption on biochar to limit harm to unidentified targets. However, irreversible sorption could restrict bioefficacy thereby compromising its usefulness as a vital crop herbici...

Soil plays a primary role in the activity of plant allelochemicals in natural and agricultural systems. In this work, we compared the phytotoxicity of three natural hydroxycoumarins (umbelliferone, esculetin, and scopoletin) to different model plant species (Lactuca sativa, Eruca sativa, and Hordeum vulgare) in Petri dishes, and then selected the m...

Allelochemicals have been proposed as eco-friendly herbicides, but they often display a limited performance under field conditions because of a short persistence in soils. In this study, incorporation into organoclay granules was investigated as a strategy to protect the allelochemical scopoletin from rapid biodegradation processes and prolong its...

Biochar is a nanoengineered sorbent proposed to control the contamination derived from the presence of residual concentrations of sulfonamides in soil. In this work, we evaluated the sorption of sulfanilamide (SFA) in commercial biochar (BC) produced at 500 °C from oak hardwood (Quercus ilex) and its analog activated with 2% (w/w) Fe (BC-Fe). Subse...

Allelochemicals have been proposed as environmentally friendly bioherbicides, but their short persistence in soils often limits their performance as natural weed management products. In this study, incorporation into organoclay granules was investigated as a strategy to protect the allelochemical scopoletin from rapid biodegradation and prolong its...

Plant monoterpenes have received attention for their ecological functions and as potential surrogates for synthetic herbicides, but very little is known about the processes that govern their behavior in the soil environment, and even less about the possible enantioselectivity in the functions and environmental behavior of chiral monoterpenes. We ch...

We assessed the effect of three organic amendments and two organo-clays on sorption, persistence, and phytotoxicity of scopoletin, an allelochemical compound with potential as bioherbicide, in a Mediterranean alkaline soil. The aim was to elucidate whether the phytotoxicity of scopoletin could be expressed better in amended than unamended soil. The...

Based on the effects that allelochemicals can exert over organisms, their use as alternatives to synthetic pesticides has been proposed. To this aim, it is important to understand their behavior in soils as allelochemicals can readily dissipate by different routes. In this work, novel granules based on the commercial organoclay Cloisite® 10A were p...

The sorption of the allelochemical scopoletin (7-hydroxy-6-methoxycoumarin) was studied in eight agricultural soils and different model sorbents. We also determined its degradation in selected soils and related sorption and degradation results to the expression of scopoletin phytotoxicity in soil towards two model plant species, Eruca vesicaria and...

Bicyclopyrone is an herbicide that is marketed for the control of herbicide‐resistant weeds. However, there is a lack of extensive data on its sorption and factors that control its sorption in the soil system. In this study, we evaluated a series of 25 different soils, with a variety of properties to determine if an empirical relationship could be...

Chirality has received progressive attention in the field of pesticides. Enantiomers of chiral pesticides have identical physicochemical properties but, commonly, they exhibit stereoselective response with chiral host systems and, therefore, enantioselectivity against the target pest. Despite this, approximately 30% of the pesticides in current use...

A low cost bentonite was modified with Fe³⁺ and hexadecyltrimethylammonium (HDTMA) cations and subsequently optimized to be used in small-scale water filter systems. Two types of formulations were assessed: immobilization of modified clays on anthracite particles and their extrusion as pellets using the natural binders, colophony resin and carnauba...

BACKGROUND Allelochemicals can act as biopesticides or enhance the action of synthetic pesticides. In this work, we assessed the bioavailability of the allelochemical coumarin in soils amended with fresh or field‐aged biochars (BCs). The fresh BC from oak wood (Fresh BC) was prepared at 550 °C and was buried for aging in two different places: in a...

Mortars containing biocidal chemicals are widely applied as they show resistance to microbiological growth, thus preventing the aging of heritage materials. However, factors such as ultraviolet radiation, the weather etc. could greatly affect the biocidal activity of the active principles in mortars. The aim of this study was to optimize the prepar...

Activation treatments are often used as a means of increasing a biochar’s sorption capacity for agrochemical compounds but can also provide valuable insight into sorption mechanisms. This work investigates the effects of H2O2 activation on a low-temperature (350 °C) grape wood biochar, evaluates subsequent changes to the removal efficiency (RE) of...

In this study, we assessed the sorption, dissipation, and leaching of the herbicide mesotrione in soil amended with fresh and field-aged biochars, when added to the soil. The aging process was performed by burying the fresh biochar at 10 cm depth in three soils located in different points across the USA [Wisconsin (ABC_WI), Idaho (ABC_ID) and South...

Coumarins represent an important family of allelochemicals with fungicidal, bactericidal, insecticidal, nematicidal, and herbicidal properties. Like for other allelochemicals, the short persistence of coumarins in soils can reduce their biological activity and hamper their application as environmentally friendly agrochemicals. We evaluated the sorp...

A local low value bentonite from Southern Spain (Raw Bentonite), previously decarbonated (Bent), was modified to improve its pesticide adsorption capacity with Fe ³⁺ , hexadecyltrimethylammonium (HDTMA) and the biopolymer chitosan (CH). Adsorption of pesticides on powdered samples showed that Fe ³⁺ and HDTMA were appropriate modifiers for this purp...

This study investigates the changes in sorption/desorption, dissipation and leaching of the two enantiomeric forms of the allelochemical carvone, R-carvone and S-carvone, after amending an agricultural soil sample with two nanoengineered sorbents: biochar (BC) and organoclay (OCl). The sorption of carvone enantiomers was non-enantioselective and si...

Knowledge of long-term pesticide behavior in biochar (BC) amended soil is still contradictory. In this work, we compared the sorption of three highly persistent and ionizable pesticides [two anionic (imazamox and picloram) and one weak base (terbuthylazine)] on both fresh and field-aged BC as well as on a soil amended with these biochars. The aging...

The activity of allelochemicals in agroecosystems are highly dependent on their soil persistence. The aim of this work was to establish a link between the soil persistence of salicylic acid (SA) and its bioactivity, to better understand the mechanisms of allelochemical-mediated soil-plant interactions. Incubation and bioassay experiments were condu...

The use of monoterpenes as agrochemicals has been proposed, but the behavior of this family of compounds once they reach the soil environment has not been completely examined. In this work, we investigated the sorption of the two optical isomers of the monoterpene carvone, R-carvone and S-carvone, on different soils and model sorbents, as well as t...

Addition of biomass chars (biochar) to soil reportedly suppresses emissions of nitrous oxide (N2O), a potent greenhouse and ozone-depleting gas, but the causes and endurance of the effect are unclear. To determine whether adsorption may play a role, adsorption isotherms of N2O were constructed at 273 K on outgassed samples of anoxically-prepared wo...

The objective of this work was to determine the effect of the mucilage extracted from Chia seeds (Salvia hispanica L.) as soil amendment on soil physical properties and on the sorption-desorption behaviour of four herbicides (MCPA, Diuron, Clomazone and Terbuthylazine) used in cereal crops. Three soils of different texture (sandy-loam, loam and cla...

Sorption, persistence, and leaching of the enantiomers of the herbicide imazaquin, S-imazaquin and R-imazaquin, in two soils under different application regimes were studied. Imazaquin dissipation was evaluated after a single application of the racemic herbicide and the pure enantiomers, and after a repeated application of the racemic herbicide. Th...

Biochar (BC), solid biomass subjected to pyrolysis, can alter the fate of pesticides in soil. We investigated the effect of soil amendment with several biochars on the efficacy of two herbicides, clomazone (CMZ) and bispyribac sodium (BYP). To this aim, we evaluated CMZ and BYP sorption, persistence and leaching in biochar amended soil. Sorption of...

Background: Biochar, a carbon-rich product of biomass pyrolysis, could limit glyphosate transport in soil and remediate contaminated water. The present study investigates the sorption/desorption behavior of glyphosate on biochars prepared from different hardwoods at temperatures ranging from 350°C to 900°C to elucidate fundamental mechanisms. Res...

The potential use of allelopathic and signaling compounds as environmentally friendly agrochemicals is a subject of increasing interest, but the fate of these compounds once they reach the soil environment is poorly understood. In this work, we studied how the sorption, persistence, and leaching of the two enantiomers of the phytohormone abscisic a...

Laboratory and field experiments were conducted to assess how the addition of oleate-modified hydrotalcite (clay) and biochar (BC) to an agricultural soil affected the sorption, leaching, persistence, and enantiomeric composition of soil residues of two chiral fungicides, tebuconazole and metalaxyl. Laboratory experiments showed that the sorption o...

Although enantioselective sorption to soil particles has been proposed as a mechanism that can potentially influence the availability of individual chiral pesticide enantiomers in the environment, environmental fate studies generally overlook this possibility and assume that only biotic processes can be enantioselective, whereas abiotic processes,...

Little is known about the enantioselectivity of the processes that determine the efficacy and environmental fate of natural compounds with potential to be used as environmentally-friendly agrochemicals. We conducted incubation and column leaching experiments to examine the extent and enantioselectivity of the sorption, persistence, and leaching of...

A large number of pesticides are chiral and reach the environment as mixtures of optical isomers or enantiomers. Agricultural practices can affect differently the environmental fate of the individual enantiomers. We investigated how amending an agricultural soil with composted olive-mill waste (OMWc) or its biochar (BC) at 2% (w:w) affected the sor...

Mechanisms governing the enantioselectivity of the processes that determine the behavior of chiral pollutants in the environment need to be better understood. Understanding these mechanisms should help improve predictions of the hazards and risks chiral compounds can pose to people and the environment. We report the results of batch sorption experi...

The goal of this work was to prepare and characterize a novel functional material by the modification of SAz-1 montmorillonite with the cationic polymer hexadimethrine (SA-HEXAD), and to explore the potential use of this nanocomposite as a pesticide adsorbent. Comparative preparation and characterization with the well-known hexadecyltrimethylammoni...

Soil incubation and column leaching experiments were conducted to address the question of whether the type of formulation (unsupported vs clay-supported) and repeated applications of the chiral fungicide (RS)-metalaxyl affected the enantioselectivity of its dissipation and leaching in a slightly alkaline, loamy sand agricultural soil. Regardless of...

We recently proposed that weak acids (AH) adsorb to partially-oxidized carbonaceous materials in part by forming strong hydrogen bonds with acidic surface groups, depicted by (A...H...O-surf), known as negative charge-assisted hydrogen bonds, (-)CAHBs. Here we use competition experiments to show that sorption of AH on carbon nanotubes (CNTs) can be...

Long-chain (C18) unsaturated fatty acid anions, elaidate (ELA), oleate (OLE), linoleate (LINO), and linolenate (LINOLEN), were intercalated into Mg/Al (3:1) layered double hydroxide (LDH) and the resultant organo-LDH nanohybrid materials were characterized and subsequently evaluated as sorbents of six pesticides (clopyralid, imazethapyr, diuron, at...

Certain soil management practices can affect the enantioselective behavior of chiral pesticide enantiomers in agricultural soils. In this work, laboratory experiments were conducted to study the effects of olive-mill waste (OMW) addition to a Mediterranean agricultural soil on the enantioselectivity of sorption, degradation, and leaching processes...

Improving the existing knowledge on the enantioselectivity of processes affecting chiral pesticide enantiomers in the environment is necessary to maximize the efficacy and minimize the environmental impact caused by the use of pesticides with chiral properties. In this work, the enantioselectivity of the sorption, degradation, and leaching processe...

Laboratory and field experiments were conducted to evaluate the effect of olive-mill waste (OMW) addition to a Mediterranean olive grove soil on sorption, persistence, and mobility of two herbicides which are simultaneously applied for weed control in olive groves: terbuthylazine (TA) and fluometuron (FM). Laboratory batch sorption experiments show...

We studied the interaction between the naturally occurring polycation spermine (SPERM) and Na-exchanged SWy-2 Wyoming montmorillonite (Na-SWy-2 Mt) and between spermine-exchanged montmorillonite (Mt- SPERM) and the herbicide fluometuron. Mt-SPERM with spermine contents ranging between 0 and 1.2 times the cation exchange capacity (CEC) of Na-SWy-2 w...

Research on organoclays as sorbents of pesticides has shown the usefulness of these materials both as soil amendments and as pesticide supports, to prolong the effi cacy and reduce the environmental impact of soil-applied pesticides. Organoclays can also be formed in situ by direct modifi cation of smectiterich soil clays through treatment with app...

The use of pesticides in agriculture has become a source of pollution of soil and water in the last decades. Extensive pesticide transport losses due to leaching and runoff produce nonpoint source contamination of soils and water. One of the soil processes that reduce pesticide transport losses is adsorption by soil particles; therefore, enhancemen...