ChapterPDF Available

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



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 CO 2 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.
Selection of our books indexed in the Book Citation Index
in Web of Science™ Core Collection (BKCI)
Interested in publishing with us?
Numbers displayed above are based on latest data collected.
For more information visit
Open access books available
Countries delivered to Contributors from top 500 universities
International authors and editor s
Our authors are among the
most cited scientists
We are IntechOpen,
the world’s leading publisher of
Open Access books
Built by scientists, for scientists
TOP 1%
Degradation Process of Herbicides
in Biochar-Amended Soils: Impact
on Persistence and Remediation
Kamila CabralMielke, Kassio FerreiraMendes,
Rodrigo Nogueirade Sousa
and Bruna Aparecidade Paula Medeiros
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 unde-
sirable 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.
Keywords: bioavailability, sorption, weed control, pollution soil
. Introduction
Herbicides are the pesticides most applied in modern agriculture for weed
control worldwide, in pre-emergency, directly in the soil, or in post-emergence
in leaves. Regardless of the application of herbicides, these reach the soil and may
persist with residual effect (carryover) or contaminate the non-target organism and
environment. The behavior of the herbicide in the soil is governed by the physico-
chemical properties of the molecule and the soil and can have retention, transport,
and transformation processes [1]. In transformation processes, the herbicide
molecule is degraded into secondary compounds (metabolites) by physical (photo-
degradation), chemical, and biological processes (Figure ) [2].
Biological degradation is the most common way to dissipate the herbicides in
the environment, and it is carried out mainly by the soil microbiota which use the
herbicide molecules as an energy source and transforms it into compounds without
herbicidal action, the process is also known as detoxification [3, 4]. The chemical
complexity of the herbicide determines the higher or lower facility of microorgan-
isms to degrade the molecules, characterizing it in low or high persistence in the soil
[5], being measured by degradation or dissipation half-life time (DT50) in labora-
tory or field conditions, respectively [2].
The degradation of herbicides in the soil by microorganisms can be aerobic
(with oxygen) or anaerobic (without oxygen). In the presence of oxygen, the herbi-
cide is mineralized in CO2 and water. Without oxygen, the herbicide is mineralized
in CH4, CO2, and water [6]. The efficiency of aerobic degradation of herbicides is
higher than the anaerobic. The aerobic bacteria oxygen act as an oxidizing agent,
and they are present in the region of the soil where there is a higher content of
organic matter (OM) and an excellent soil-water-air ratio for the microbiota [7]. In
conditions of absence of oxygen, the herbicide can become more persistent in the
soil and its degradation pathways are different from microorganisms with aerobic
metabolism [8].
The addition of organic materials, like biochar, in the soil directly influences
the microbial community, responsible for herbicide degradation [9]. Biochar is a
carbonaceous material produced by different feedstocks in pyrolysis conditions
with the limited presence of oxygen. Naturally, biochar is found in the anthro-
pogenic soil, known as “Terra Preta de Índio, i.e., Amazonian Dark Earths in
the Amazon, which gave rise to synthetic biochar produced worldwide [10].
Pyrolyzed feedstocks and pyrolysis conditions determine the physico-chemical
properties of biochar, such as nutrient content, porosity, specific surface area,
among others.
Figure 1.
Degradation process (chemical, biological, and photodegradation) of herbicides in the soil.
Degradation Process of Herbicides in Biochar-Amended Soils: Impact on Persistence and…
In agricultural soils, the biochar has been added to increase porosity, water-
holding capacity, reduce acidity, sequester carbon, reduction of greenhouse gas
emissions, plant growth promotion, improve soil fertility, and immobilize (reme-
diation) herbicides by increasing sorption and microbial diversity [11]. This chapter
showed that is possible to recommend the addition of biochar in the soil to interfere
in the persistence or remediation processes of the herbicide.
. Biochar characteristics
Biochar is the carbon-rich product resulting from the pyrolysis of organic resi-
dues such as wood, animal wastes, crop residues, and biosolids [12]. The feedstock
usually determines the chemical composition, quantity of macropores, and nutrient
content in biochar. Pyrolysis conditions (such as temperature, heating rate, and
residence time) determine the morphology and surface structure changes in feed-
stock and C/H content [11]. The dominant properties affecting herbicide sorption
and degradation by biochar include porosity, specific surface area, pH, functional
groups, carbon content and aromatic structure, and mineralogical composition [13].
More porous structures and higher specific surface area will result in higher
sorption capacities and lower degradation of herbicides [13]. Higher pH of biochar
can accelerate the hydrolysis of organophosphorus and carbamate herbicides in the
soil through the alkali catalysis mechanism [14]. Surface functional groups includ-
ing carboxylic (–COOH), hydroxyl (–OH), lactonic, amide, and amine groups are
essential for the sorption capacity of biochar [15, 16]. Carbon content and aromatic
structure can increase herbicide sorption and reduce their bioavailability to be
degraded [13]. The mineralogical composition can reduce the bioavailability of
herbicides through surface chelation and/or surface acidity mechanisms [17].
Biochar amendment also affects the degradation of herbicides in the soil in
several ways and the effects can be either stimulatory or suppressive [18]. Biochar
may contain available nutrients that stimulate overall microbial activity and,
thus, degradation of herbicides [19, 20]. However, the degradation of herbicides
in biochar-amended soils is most commonly reduced because herbicide sorption
increases [21]. Biochar also sorbs dissolved organic carbon (OC), which can con-
tribute to co-metabolic biodegradation [22]. Some changes in the degradation rate
can be a result of indirect effects of biochar amendment, e.g., changes in soil pH,
albedo, and aeration [18].
. Microbial diversity in biochar-amended soils
Soil correction with biochar can affect the soil microbiota in different ways: (1)
It can provide an increase in the microbiota [23, 24]; (2) It can negatively affect the
resident microbiota by the amount of organic substances (volatile compounds)
formed in the production of biochar [25, 26]; or (3) It may not effect the soil micro-
biota [27, 28]. The possible interaction mechanisms of biochar and soil microbiota
are exemplified in Figure  [29, 30]. The physical–chemical structures of the
biochar surface (macro and micropores, roughness, surface load, and hydrophobic-
ity) are a refuge for the soil microbiota [31, 32], where microorganisms can find
nutrients and ions adsorbed in biochar particles useful for their growth [29, 33]. In
addition, biochars can contain significant amounts of organic substances (volatile
organic compounds and free radicals) [34, 35], improve the soil’s physical–chemical
properties, which are important for microbial growth by modifying habitats (aera-
tion, water content, and pH) [36], affect the enzymatic activity of the soil [37, 38],
and increase the sorption of herbicides, reducing the bioavailability and toxicity of
these agrochemicals for the soil microbiota [29, 39, 40].
Biochar-amended soil has a higher respiratory rate and microbial communi-
ties due to carbon mineralization by soil microorganisms [41]. Microbial biomass
carbon and nitrogen increased by 18% and 63% with the application of 1% of
sugarcane bagasse biochar [42]. The role of biochar nutrients in the biodegradation
of coexisting dichlobenil and atrazine in soil by their respective bacterial degraders
was evaluated. The degradation increased with increasing biochar content, due to
nutritional stimulation on microbial activities [43]. The application of hardwood-
derived biochar increased atrazine mineralization by stimulating atrazine-adapted
microflora compared to unamended soil [19]. Soil amended with biochar derived
from wheat straw increased the abundance and diversity rate of bacteria and fungi
beneficial to plants in the rhizosphere of wheat seedlings [24]. In addition, these
microorganisms use fomesafen as a source of nutrients, which favors their prolifera-
tion from the soil [24]. The change and proliferation of the soil microbiota with the
addition of biochar is related to the chemical characteristics of biochar (mainly pH
and nutrient content) and physical properties (pore size, pore-volume, and specific
surface area), OM content, and water retention that provide favorable conditions
for soil microbiota [28]. Although soil microbial biomass is generally benefited with
the addition of biochar, the response depends on the type of raw material, pyrolysis
temperature, and biochar application rate, since these factors directly interfere with
the physical–chemical characteristics of biochar and consequently on the response
of the microbiota in herbicide degradation. The proposed mechanisms involved in
biochar and microbiota interactions require further studies to elucidate the impact
of biochar on soil microbial activity.
. Influence of biochar amendment in soil on the herbicide degradation
Herbicides are applied to the soil to control weeds during a certain time after
application; however, long persistence may affect the subsequent crop, a process
known as carryover. Therefore, the process of degradation of the herbicide is
Figure 2.
Interactions between biochar and soil microbiota and environmental effects. Source: Adapted from Zhu
et al. [29].
Degradation Process of Herbicides in Biochar-Amended Soils: Impact on Persistence and…
important for the dissipation of herbicides in the soil when the intention is the
remediation of the product. However, under agronomic conditions in which a
residual effect of the herbicide on the soil is desired for weed control, the addition
of biochar can reduce the persistence of the product, consequently reducing its
effectiveness in management [2, 9, 44].
The degradation of herbicide molecules into secondary compounds (metabo-
lites) can occur by biotic (biological degradation) or abiotic (hydrolysis, reduction,
oxidation, and photolysis) processes [45]. Biodegradation, carried out by the soil
microbiota (bacteria, fungi, protozoa, and actinomycetes), is the main decom-
position pathway for most herbicides [13, 46]. Microorganisms can use herbicide
molecules as an energy source and transform them into compounds without
herbicide action, a process known as catabolism, or through co-metabolism, in
which herbicide degradation requires the presence of a growth substrate that is used
as primary carbon and energy source [3, 47], i.e., microorganism does not obtain
energy or benefit from the herbicide degradation. The transformation process is
usually mediated by non-specific enzymes that are capable to transform various
organic compounds [4]. Herbicides have varied susceptibility to microbial degra-
dation depending on the complexity of the molecule that influences low or high
persistence in the soil [5].
Microbial degradation generally reduces the DT50 of herbicides in the soil;
however, the addition of biochar, according to studies performed, may increase
or decrease the DT50 values, depending on the herbicide and pyrolyzed feedstock
(Table). The high sorption capacity for herbicides in the biochar-amended soil
decreases herbicide degradation, providing a higher DT50 than the unamended
soil [46, 49]. For example, less atrazine degradation was observed in amended
soils with sugarcane bagasse biochar (0.5% w/w) (Table), increasing in 15days
the DT50 of the herbicide in relation to unamended soil [49]. Flumioxazin DT50
increased by ~10 days when bamboo biochar (10% w/w) was added compared to
unamended soil (Table) [51]. The DT50 of 2-methyl-4-chlorophenoxyaceticacid
(MCPA) increased from 5.2days (unamended soil) to 21.5days in amended soil
with 1% of wheat straw biochar [59].
The application of biochar can also increase soil microbial activity, improving
herbicide degradation [29, 60]. The increase in microbial biomass may be due to the
addition of available organic substrates, which are the main energy source readily
available to soil microorganisms [55]. The high content of dissolved OC in the soil
MO can reduce herbicide sorption by biochar particles, as dissolved OC competes
with herbicide molecules to occupy available biochar sorption sites [61]. Biochar
also sorbs dissolved OC, which can contribute to co-metabolic biodegradation
[22]. Some changes in degradation rate may result from indirect effects of biochar
amendment, e.g., changes in soil pH and aeration [18]. The highest degradation of
oxyfluorfen was observed in amended soils with different rates of application of
rice husk biochar, decreasing DT50 between 2 and 23days compared to unamended
soil (Table) [50]. Alachlor mineralization increased up to 50% using biochar
derived from soybean stoves, sugarcane bagasse, and wood chips compared to
unamended soil (Table) [58].
Photolysis and hydrolysis are the main abiotic processes involved in herbicide
degradation [48, 62]. Photolysis or photodegradation occurs when herbicides are
exposed to sunlight [63] and can be direct (a herbicide molecule absorbs light
energy, is later excited and transformed) or indirect (species photochemically
produced in the soil matrix react with the herbicide molecule triggering its degra-
dation) [64]. Water degrades herbicides by dividing large molecules into smaller
molecules, breaking them in the process called hydrolysis [65]. The hydrolysis of
herbicides in the soil can be influenced by several factors such as dissolved ion
Soil texture () Feedstock Application
rate ()b
temperature (°C)
Herbicide DT (biochar-
amended soil)
DT (unamended
Sand Silt Clay OMa
Australia n.a. n.a. 36.1 2.4 Wheat straw 0.5 450 Atrazine 61.5d76.5dNag et al. [44]
n.a. n.a. 28 4.0 0.5 65.9d68.6d
Australia n.a. n.a. 36.1 2.4 Wheat straw 0.5 450 Trifluralin 73.6d75.4dNag et al. [44]
n.a. n.a. 28 4.0 0.5 63.2d66.4d
Brazil n.a. n.a. n.a. n.a. Industrial-
production of
3350-550 Sulfometuron-
52.1 36.6 Alvarez et al.
China n.a. n.a. n.a. 3.2 Sugarcane bagasse 0.2 500 Atrazine 38.5 28.1 Huang et al.
0.5 45.0
2.0 0.2 35.5 23.7
0.5 41.2
3.6 0.2 41.2 39.8
0.5 54.8
Degradation Process of Herbicides in Biochar-Amended Soils: Impact on Persistence and…
Soil texture () Feedstock Application
rate ()b
temperature (°C)
Herbicide DT (biochar-
amended soil)
DT (unamended
Sand Silt Clay OMa
China 21.4 51.4 27.2 2.8 Coal 1.5 n.a.cIsoproturon 53.3 54.6 Si et al. [46]
27.9 33.6 38.5 1.5 1.5 67.9 16
44.9 39.5 15.6 1.2 1.5 58.2 15.2
China 32.1 24.7 43.2 0.84 Rice husk 0.5 500 Oxyfluorfen 59 65 Wu et al. [50]
73.2 12.3 14.5 0.98 0.5 104 108
55 23.1 21.9 2.2 0.5 43 45
Soil texture () Feedstock Application
rate ()b
temperature (°C)
Herbicide DT (biochar-
amended soil)
DT (unamended
Sand Silt Clay OMa
China 7 7.4 4.4 18.2 1.5 Cornstalk 10 500 Flumioxazin 15.4 11.1 Chen et al. [51]
Rice husk 500 16.7
Bamboo 700 23.2
21 17 62 1.7 Cornstalk 500 18.5 11.5
Rice husk 500 22.3
Bamboo 700 25.4
6.8 55.3 37.9 3.8 Cornstalk 500 20.5 15.4
Rice husk 500 22.6
Bamboo 700 29.2
3.7 64.7 31.6 4.3 Cornstalk 500 21.0 20.8
Rice husk 500 24.7
Bamboo 700 30.7
Germany 30.1 62.5 7.8 1.2 Hardwood 0.1 500 Atrazine 74.0d72.4dJablonowski et
al. [19]
24.4 25.2 50.3 3.1 0.1 53.0d42.6d
Degradation Process of Herbicides in Biochar-Amended Soils: Impact on Persistence and…
Soil texture () Feedstock Application
rate ()b
temperature (°C)
Herbicide DT (biochar-
amended soil)
DT (unamended
Sand Silt Clay OMa
India 56.6 29.6 13.8 n.a. Rice straw 0.25 350 Bispyribac-
10.7 2 7.1 Sharma et al.
0.5 11.5
0.25 550 8.8
0.5 9.9
Latvia 89.2 8.9 1.9 n.a. Wood chips 5.3 725 MCPA 1986f94.5fMuter et al.
4.1 3854f11.1f
Wheat straw 5.3 1636f94.5f
4.1 15.3f11.1f
Malaysia 40 21.5 37. 9 0.99 Oil palm empty
fruit bunches
1300 Imazapic 46.2 34.6 Yavari et al.
Imazapyr 53.3 38.5
Rice husk Imazapic 40.7 34.6
Imazapyr 46.3 38.5
Soil texture () Feedstock Application
rate ()b
temperature (°C)
Herbicide DT (biochar-
amended soil)
DT (unamended
Sand Silt Clay OMa
Russia 3.1 30.4 66.5 n.a. Woods (Betula sp.
and Piceaabies)
1400 Diuron 47 40 Zhelezova et
al. [18]
10 42
20 56
30 45
1Glyphosate 187 17
10 151
20 131
30 51
83.7 8.8 7.5 n.a. 1Diuron 58 112
10 33
20 35
30 40
1Glyphosate 83 182
10 66
20 78
30 53
Degradation Process of Herbicides in Biochar-Amended Soils: Impact on Persistence and…
Soil texture () Feedstock Application
rate ()b
temperature (°C)
Herbicide DT (biochar-
amended soil)
DT (unamended
Sand Silt Clay OMa
Spain 24 47 30 1.3 Hardwood
2350 Clomazone 97 29 Gámiz et al.
400 77
700 99
350 107
400 65
700 67
350 Bispyribac-
n.a. 21
400 n.a.
700 84
350 n.a.
400 n.a.
700 33
Soil texture () Feedstock Application
rate ()b
temperature (°C)
Herbicide DT (biochar-
amended soil)
DT (unamended
Sand Silt Clay OMa
Spain 43 32 23 0.9 Olive mill waste 2.5 n.a. Metribuzin 39 22 López-Piñeiro
et al. [55]
Olive mill waste
plus leaves
2.5 13
53 32 14 0.6 Olive mill waste 2.5 49 35
Olive mill waste
plus leaves
2.5 19
43 14 42 0.9 Olive mill waste 2.5 40 29
Olive mill waste
plus leaves
2.5 18
USA n.a. n.a. n.a. 0.7 Sugarcane bagasse 0.2 350 Metribuzin 54 25 White Junior
et al. [56]
Sugarcane bagasse 0.1 700 25
n.a. n.a. n.a. 0.8 Sugarcane bagasse 0.2 350 74 57
Sugarcane bagasse 0.1 700 39
n.a. n.a. n.a. 1.2 Pine wood 0.4 400 39 28
USA 22 55 23 >2 Mixed sawing 5500 Acetochlor 34.5 9.7 Spokas et al.
USA n.a. n.a. n.a. n.a. Soybean waste 10 500 Alachlor 4.6e10.4eMendes et al.
Sugarcane bagasse 350 3.4e
Wood bark (grape) 500 3.8e
aOrganic Matter; bApplication rate in relation to soil mass (ww−); cData not available; dDegradation (); eMineralization () to CO; fHerbicide concentration after incubation period (μgkg−).
Table 1.
Effect of biochar amendment in soil on the degradation half-live time (DT50 - days) of different herbicides.
Degradation Process of Herbicides in Biochar-Amended Soils: Impact on Persistence and…
concentration, soil pH, and content of clays and metal oxides capable of catalyzing
this herbicide degradation process [14, 66].
The application of biochar can influence the degradation of herbicides by
hydrolysis and photolysis, since persistent free radicals existing or photogenerated
in biochars can react with the herbicide by the activation of other free radicals such
as hydroxyl, sulfate, anion, and superoxide [67, 68]. In addition, the increase in soil
pH, the presence of active groups on the mineral surface of biochar, and the high
sorption of herbicides have a direct effect on the chemical degradation processes of
herbicides [64, 66]. Atrazine was hydrolyzed by 27.9% in the presence of biochar
derived from pig manure (700°C) after 12h due to the mineral surface and dis-
solved metal ions released from biochars that catalyze hydrolysis [66]. In contrast,
imazapic and imazapyr were resistant to degradation by hydrolysis in amended soil
with biochar derived from empty fruit bunch of oil palm and rice husk, and their
DT50s increased by ~6 to 12days because the photodegradation rate diminished [53]
(Table). The addition of biochar to the soil at 1 or 5% inhibited the photodegrada-
tion of metribuzin and its metabolites deamino (DA), deaminodiketo (DADK), and
diketometribuzin (DK), which increased their DT50s due to the immobilization of
these compounds the surface layer of the biochar [64]. Therefore, the application
of biochar has a direct impact on herbicide degradation processes and should be
constantly examined for its application in the soil.
. Factors affecting herbicide degradation in biochar-amended soils
The impact on the degradation of herbicides due to their high sorption in the
biochar particles depends on the rate of biochar applied to the soil. The applica-
tion of different rates of application of hardwood biochar in Rhodic Ferralsol soil
increased atrazine degradation by 49% (0.1% of biochar), 51% (1.0% of biochar),
and 62% (5.0% of biochar) after 88days of incubation (Table) [19]. DT50 of
isoproturon in unamended Alfisol was 16days, however, when biochar was added
at 1.5 and 5%, DT50 increased to 67 and 136days, respectively (Table) [46], i.e.,
the persistence of isoproturon is prolonged as the rate of biochar added to the soil
increases. DT50 of fomesafen increased from 34.6days in unamended soil to 51, 83,
and 160days in amended soils with rice husk biochar at 0.5, 1, and 2%, respectively
[61]. The increased persistence of fomesafen can be explained by the higher sorb
capacity of biochar and, therefore, little bioavailability of the herbicide for micro-
bial degradation.
Pyrolysis temperature defines the physicochemical characteristics of bio-
chars [69]. Generally, biochar produced at relatively high pyrolysis temperatures
(>500°C) presents an increase in specific surface area, microporosity, and hydro-
phobicity, improving herbicide sorption [70]. However, even with higher herbicide
sorption capacity, degradation at high pyrolysis temperatures may be more intensi-
fied than low temperatures. The addition of sugarcane bagasse biochar produced
at 700°C in clay soil decreased the DT50 of metribuzin from 57 (unamended soil)
to 39days, but when biochar was produced at 350°C, DT50 went from 57 to 74days
(Table) [56]. These conflicting results could be due to the impact of ash on the
alkalinity of the soil amended with biochar produced at 700°C (20.3% of ash),
which increased the soil pH and improved the conditions for the degradation of
metribuzin, and to the greater amount of dissolved OC from biochar produced
at 350°C (3.78mgg−1), which is more preferred by microorganisms as substrate,
increasing the persistence of the herbicide. The variation in pyrolysis temperature
of eucalyptus wood residue biochar affected the total hexazinone unavailable
(mineralized + non-extractable residue) being higher for 850°C (46%) and 950°C
(49%) compared to biochar pyrolised at 650°C (33%) and 750°C (42%) [71]. The
addition of biochar did not alter the mineralization of hexazinone, but it did reduce
the bioavailability of this herbicide in the soil due to the greater amount of non-
extracted residue, reducing the risk of environmental contamination [71].
Aging alters the properties of biochar, affecting the degradation of herbicides,
however, these changes are not fully elucidated [72]. Glyphosate showed no varia-
tion in degradation in two tropical soils (Ultisol and Alfisol) amended with euca-
lyptus biochar aged [73]. The aging of soil-wood biochar mixtures (Betula sp. and
Piceaabies) decreased glyphosate and diuron sorption compared to fresh biochar
amended soil [18]. In addition, herbicide degradation was not affected by changes
or biochar aging in the soils studied [18]. The degradation of S-metolachlor was not
affected with the addition of three macadamia nutshell biochars aged [74]. The per-
sistence of mesotrione in different soils amended with fresh and aged biochar was
similar to unamended soils [75]. In contrast, the extractable amounts of picloram
were 20 and 50% lower for soils amended with fresh and aged oak wood biochar,
respectively, in relation to unamended soil [76]. The addition of 10% fresh biochar
from the olive oil industry increased the DT50 of metribuzin from 20 (unamended
soil) to 30.2days, however, the DT50 decreased to 6.4days with the addition of aged
biochar, possibly because microorganisms in soil aged with biochar used metribuzin
as a source of carbon and energy instead of the labile fraction of soil OM (Table  )
[55]. The effects of biochar on herbicide degradation in soils should not be general-
ized due to the different characteristics of biochars and the complexity of the soil
system. The variation of temperature and application rate of biochar can bring dif-
ferent degradation responses for each herbicide studied. Furthermore, the aging of
biochar in the soil can influence the bioavailability of herbicides in soil solution by
altering the sorption capacity of the biochar; therefore, the conditions of pyrolysis,
type of feedstock as well as aging must be taken into consideration when planning
its use in agriculture and for soil remediation purposes [18].
. Simultaneous use of herbicides and biochar
In an agricultural context, the property of biochar that offers potential for
herbicide sorption (environmental remediation) can also decrease the efficacy of
herbicides applied to the soil, influencing their bioavailability and susceptibility to
leaching and consequently their degradation [77]. The bioavailability of diuron and
microbial degradation was reduced in soils amended with rice straw biochar, which
decreased the effectiveness of diuron to jungle rice (Echinocloa colona) control
[78]. The addition of wheat straw biochar to the soil inactivated the herbicides
atrazine and trifluralin, resulting in increased seed germination and biomass of
annual ryegrass (Lolium rigidum). In this study, the efficacy of the herbicides for
ryegrass control was achieved when the application doses were four times higher
than recommended [44]. In a bioassay with Echinochloa colona, injuries 9days after
planting decreased with increasing application rates of rice straw biochar indicating
that sorption of clomazone increased and directly influenced the bioavailability
of herbicide in the soil [79]. The control efficiency of S-metolachlor was evaluated
on green foxtail (Setaria viridis) in soil amended with wood biochar at different
application rates (0, 0.5, 1, and 2%) [80]. S. viridis control at the highest application
rate (2%) was lower than the other application rates evaluated, however, better than
the control treatments (no herbicide) [80].
The biochar applied to soil also influences the soil physicochemical properties
and the improved nutritional availability of these directly impacts crop growth
and consequently weed growth [81]. Soil amended with walnut shell biochar
Degradation Process of Herbicides in Biochar-Amended Soils: Impact on Persistence and…
(5Mgha−1) for 4years was evaluated for weed control [82]. Weed density was dra-
matically higher in biochar-amended soils (60-78%) compared to unamended soil,
being related to increased nutrient availability and improvements in soil physico-
chemical properties such as cation exchange capacity (CEC), density and porosity,
increased soil aeration, and water retention. The application of 2Mgha−1 of cow
bonechar prevented weed control by indaziflam which is related to the increase of
soil fertility, especially the phosphorus and carbon content, and to the increase of
pH because it is a basic material [83]. In addition, goosegrass (Eleusine indica) and
crabgrass (Digitaria horizontalis) accounted for about 99.7% of the entire weed
community infestation [83].
On the other hand, the decrease in efficacy depends on the characteristics of the
herbicide evaluated. The dose of pretilachlor to inhibit 50% of E. colona emergence
and biomass was higher in soil amended with rice-husk biochar, however, the
effectiveness of pendimethalin in controlling E. colona was not influenced by the
application rate of biochar [84]. The effectiveness on metribuzin in soils amended
with biochar was evaluated by White Junior et al. [56]. The addition rates of biochar
did not alter Palmer (Amaranthus palmeri) emergence, and it is possible that the
residual activity was sufficient to reduce germination at any rate of biochar [56].
The addition of biochar to soil increases the sorption of different herbicides and
reduces their effectiveness, which may result in the need for higher herbicide appli-
cation rates, additional application times, or more weed control operations required
[85]. Residual herbicides, applied in pre-emergence, can not provide good weed
control regardless of soil type after biochar application. This does not necessarily
mean that biochar should be avoided, however, when biochar is applied to the soil,
management practices need to be adjusted to obtain appropriate weed control [86].
. Conclusions
Modifying soil characteristics with biochar is a world-renowned emerging
practice for either environmental and/or agronomic purposes, and the benefits
these carbonaceous materials brig to the soil are clear. However, the pyrolysis
conditions for biochar production directly interfere with the physical–chemical
properties of the produced material, which govern the biochar-herbicide interac-
tions. If the objective is to apply the herbicide in pre-emergence after the addition
of biochar in the soil, care should be taken, as biochar can decrease or increase
the persistence of the chemical product, interfering in the effectiveness of weed
control over time. On the other hand, if the objective is herbicide remediation in
contaminated soils, the interference of biochar in the bioavailability of the herbi-
cide in the soil solution to increase soil microbiological diversity should be known.
The authors wish to thank the Coordination for the Improvement of Higher
Education Personnel (CAPES - 88887.479265/2020-2100) and Foundation for
Research Support of the State of Minas Gerais - Brazil (FAPEMIG - APQ-01378-21)
for the financial support.
Conflict of interest
The authors declare no conflict of interest.
Author details
Kamila CabralMielke1, Kassio FerreiraMendes1*, Rodrigo Nogueirade Sousa2
and Bruna Aparecidade Paula Medeiros1
1 Department of Agronomy, Federal University of Viçosa, Viçosa,MinasGerais,
2 Department of Soil Science, “Luiz de Queiroz” College of Agriculture, University
of São Paulo, SãoPaulo, Brazil
*Address all correspondence to:
© 2021 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms
of the Creative Commons Attribution License (
by/3.0), which permits unrestricted use, distribution, and reproduction in any medium,
provided the original work is properly cited.
Degradation Process of Herbicides in Biochar-Amended Soils: Impact on Persistence and…
[1] Arias-Estévez M, López-Periago E,
Martínez-Carballo E, Simal-Gándara J,
Mejuto JC, García-Río L. The mobility
and degradation of pesticides in soils
and the pollution of groundwater
resources. Agriculture, Ecosystems and
Environment. 2008;:247-260
[2] Mendes KF, Mielke KC,
Barcellos Júnior LH, de la Cruz RA,
Sousa RN. Anaerobic and aerobic
degradation studies of herbicides and
radiorespirometry of microbial activity
in soil. In: Radioisotopes in Weed
Research. Boca Raton: CRC Press; 2021.
pp. 95-125
[3] Maier RM. Microorganisms and
organic pollutants. In: Environmental
Microbiology. San Diego: Academic
Press; 2000. pp. 363-402
[4] Reis FC, Tornisielo VL, Martins BAB,
Souza AJ, Andrade PAM, Andreote FD,
et al. Respiration induced by substrate
and bacteria diversity after application
of diuron, hexazinone, and
sulfometuron-methyl alone and in
mixture. Journal of Environmental
Science and Health. 2019b;:560-568
[5] Bending GD, Lincoln SD,
Edmondson RN. Spatial variation in the
degradation rate of the pesticides
isoproturon, azoxystrobin and
diflufenican in soil and its relationship
with chemical and microbial
properties. Environmental Pollution.
[6] Organization for Economic
Co-Operation and Development
(OECD). Guidelines for Testing of
Chemicals - Aerobic and anaerobic
transformation in soil. Vol. Test 307.
Paris, France: OECD; 2002. p. 17
[7] Gebler L, Spadoto CA.
Comportamento ambiental dos
herbicidas. In: Manual de manejo e
controle de plantas daninhas. Passo
Fundo, RS, Brazil: Embrapa Trigo; 2008.
pp. 39-69
[8] Wang W, Wang Y, Li Z, Wang H,
Yu Z, Lu L, et al. Studies on the anoxic
dissipation and metabolism of
pyribambenz propyl (ZJ0273) in soils
using position-specific radiolabeling.
Sci Total Environ. 2014;:582-589
[9] Takeshita V, Mendes KF, Alonso FG,
Tornisielo VL. Effect of organic
matter on the behavior and control
effectiveness of herbicides in soil. Planta
Daninha. 2019;:e019214401
[10] Hilbert K, Soentgen J. From the
“Terra Preta de Indio” to the “Terra Preta
do Gringo”: A History of Knowledge of
the Amazonian Dark Earths. In:
Ecosystem and Biodiversity of
Amazonia. London: IntechOpen; 2021
[11] Ahmad M, Rajapaksha AU, Lim JE,
Zhang M, Bolan N, Mohan D, et al.
Biochar as a sorbent for contaminant
management in soil and water: A review.
Chemosphere. 2014;:19-33
[12] Lehmann J, Joseph S. Biochar for
environmental management: Science,
technology and implementation. Vol. 1.
London: Earthscan Publications; 2015
[13] Liu Y, Lonappan L, Brar SK, Yang S.
Impact of biochar amendment in
agricultural soils on the sorption,
desorption, and degradation of
pesticides: A review. Sci Total Environ.
[14] Zhang P, Wu JY, Li LI, Liu Y,
Sun HW, Sun TH. Sorption and catalytic
hydrolysis of carbaryl on pig-manure-
derived biochars. J Agro-Environ Sci.
[15] Li H, Dong X, da Silva EB, de
Oliveira LM, Chen Y, Ma LQ.
Mechanisms of metal sorption by
biochars: biochar characteristics and
modifications. Chemosphere. 2017;:
[16] Antón-Herrero R, García-
Delgado C, Alonso-Izquierdo M,
García-Rodríguez G, Cuevas J, Eymar E.
Comparative adsorption of tetracyclines
on biochars and stevensite: looking for
the most effective adsorbent. Applied
Clay Science. 2018;:162-172
[17] Wei J, Furrer G, Kaufmann S,
Schulin R. Influence of clay minerals on
the hydrolysis of carbamate pesticides.
Environmental Science & Technology.
[18] Zhelezova A, Cederlund H,
Stenström J. Effect of biochar amendment
and ageing on adsorption and
degradation of two herbicides. Water, Air,
and Soil Pollution. 2017;:216
[19] Jablonowski ND, Borchard N,
Zajkoska P, Fernández-Bayo JD,
Martinazzo R, Berns AE, et al. Biochar-
mediated [14C] atrazine mineralization
in atrazine-adapted soils from Belgium
and Brazil. Journal of Agricultural and
Food Chemistry. 2013;:512-516
[20] Safaei-Khorram M, Zhang Q, Lin D,
Zheng Y, Fang H, Yu Y. Biochar: a review
of its impact on pesticide behavior in
soil environments and its potential
applications. Journal of Environmental
Sciences. 2016;:269-279
[21] Beesley L, Moreno-Jiménez E,
Gomez-Eyles JL, Harris E, Robinson B,
Sizmur T. A review of biochars
potential role in the remediation,
revegetation and restoration of
contaminated soils. Environmental
Pollution. 2011;:3269-3282
[22] Lin Y, Munroe P, Joseph S, Kimber S,
Van Zwieten L. Nanoscale organo-
mineral reactions of biochars in ferrosol:
An investigation using microscopy.
Plant and Soil. 2012;:369-380
[23] Sun D, Meng J, Liang H, Yang E,
Huang Y, Chen W, et al. Effect of
volatile organic compounds absorbed to
fresh biochar on survival of Bacillus
mucilaginosus and structure of soil
microbial communities. Journal of Soils
and Sediments. 2015;:271-281
[24] Meng L, Sun T, Li M, Saleem M,
Zhang Q, Wang C. Soil-applied biochar
increases microbial diversity and wheat
plant performance under herbicide
fomesafen stress. Ecotoxicology and
Environmental Safety. 2019;:75-83
[25] Spokas KA, Novak JM, Stewart CE,
Cantrell KB, Uchimiya M, DuSaire MG,
et al. Qualitative analysis of volatile
organic compounds on biochar.
Chemosphere. 2011;:869-882
[26] Sun D, Lan Y, Xu EG, Meng J,
Chen W. Biochar as a novel niche for
culturing microbial communities in
composting. Waste Management.
[27] Noyce GL, Basiliko N, Fulthorpe R,
Sackett TE, Thomas SC. Soil microbial
responses over 2 years following biochar
addition to a north temperate forest.
Biology and Fertility of Soils. 2015;:
[28] Ma H, Egamberdieva D, Wirth S,
Bellingrath-Kimura SD. Effect of
biochar and irrigation on soybean-
rhizobium symbiotic performance and
soil enzymatic activity in field
rhizosphere. Agronomy. 2019;:626
[29] Zhu X, Chen B, Zhu L, Xing B.
Effects and mechanisms of biochar-
microbe interactions in soil
improvement and pollution
remediation: A review. Environmental
Pollution. 2017;:98-115
[30] Palansooriya KN, Wong JTF,
Hashimoto Y, Huang L, Rinklebe J,
Chang SX, et al. Response of microbial
communities to biochar-amended soils:
a critical review. Biochar. 2019;:3-22
[31] Noyce GL, Winsborough C,
Fulthorpe R, Basiliko N. The
Degradation Process of Herbicides in Biochar-Amended Soils: Impact on Persistence and…
microbiomes and metagenomes of
forest biochars. Scientific Reports.
[32] Rummel CD, Jahnke A,
Gorokhova E, Kühnel D,
Schmitt-Jansen M. Impacts of biofilm
formation on the fate and potential
effects of microplastic in the aquatic
environment. Environmental Science &
Technology Letters. 2017;:258-267
[33] DeLuca TH, Gundale MJ,
MacKenzie MD, Jones DL. Biochar
effects on soil nutrient transformations.
In: Biochar for Environmental
Management. London, UK: Routledge.
2015. pp. 453-486
[34] Ghidotti M, Fabbri D, Hornung A.
Profiles of volatile organic compounds
in biochar: insights into process
conditions and quality assessment. ACS
Sustainable Chemistry & Engineering.
[35] Li J, Li Q, Qian C, Wang X, Lan Y,
Wang B, et al. Volatile organic
compounds analysis and
characterization on activated biochar
prepared from rice husk. International
journal of Environmental Science and
Technology. 2019;:7653-7662
[36] Quilliam RS, Glanville HC,
Wade SC, Jones DL. Life in the
charosphere’–Does biochar in
agricultural soil provide a significant
habitat for microorganisms? Soil Biology
and Biochemistry. 2013;:287-293
[37] Lehmann J, Rillig MC, Thies J,
Masiello CA, Hockaday WC, Crowley D.
Biochar effects on soil biota–a review.
Soil Biology and Biochemistry.
[38] Pukalchik M, Mercl F, Terekhova V,
Tlustoš P. Biochar, wood ash and humic
substances mitigating trace elements
stress in contaminated sandy loam soil:
Evidence from an integrative approach.
Chemosphere. 2018;:228-238
[39] Sharma N, Kaur P, Jain D,
Bhullar MS. In-vitro evaluation of rice
straw biochars’ effect on bispyribac-
sodium dissipation and microbial
activity in soil. Ecotoxicology and
Environmental Safety. 2020;:110204
[40] Egamberdieva D, Jabbarov Z,
Arora NK, Wirth S, Bellingrath-
Kimura SD. Biochar mitigates effects of
pesticides on soil biological activities.
Environ Sustain. 2021;:335-342
[41] Pei J, Zhuang S, Cui J, Li J, Li B,
Wu J, et al. Biochar decreased the
temperature sensitivity of soil carbon
decomposition in a paddy field.
Agriculture, Ecosystems and
Environment. 2017;:156-164
[42] Irfan M, Hussain Q, Khan KS,
Akmal M, Ijaz SS, Hayat R, et al.
Response of soil microbial biomass and
enzymatic activity to biochar amendment
in the organic carbon deficient arid soil: A
2-year field study. Arabian Journal of
Geosciences. 2019;:95
[43] Qiu Y, Pang H, Zhou Z, Zhang P,
Feng Y, Sheng GD. Competitive
biodegradation of dichlobenil and
atrazine coexisting in soil amended with
a char and citrate. Environmental
Pollution. 2009;:2964-2969
[44] Nag SK, Kookana R, Smith L,
Krull E, Macdonald LM, Gill G. Poor
efficacy of herbicides in biochar-
amended soils as affected by their
chemistry and mode of action.
Chemosphere. 2011;:1572-1577
[45] Mendes KF, Sousa RN, Soares MB,
Viana DG, Souza AJ. Sorption and
desorption studies of herbicides in the
soil by batch equilibrium and stirred
flow methods. In: Radioisotopes in
Weed Research. Boca Raton: CRC Press;
2021. pp. 17-61
[46] Si Y, Wang M, Tian C, Zhou J,
Zhou D. Effect of charcoal amendment
on adsorption, leaching and degradation
of isoproturon in soils. Journal of
Contaminant Hydrology. 2011;:75-81
[47] Fritsche W, Hofrichter M. Aerobic
degradation by microorganisms. In:
Biotechnology. Germany: Wiley – VCH;
2008. pp. 1-24
[48] Alvarez DO, Mendes KF, Tosi M,
Souza LF, Cedano JCC, Souza FNP, et al.
Sorption-desorption and biodegradation
of sulfometuron-methyl and its effects
on the bacterial communities in
Amazonian soils amended with aged
biochar. Ecotoxicology and
Environmental Safety. 2021;:111222
[49] Huang H, Zhang C, Zhang P,
Cao M, Xu G, Wu H, et al. Effects of
biochar amendment on the sorption and
degradation of atrazine in different
soils. Soil Sediment Contam: An Int J.
[50] Wu C, Liu X, Wu X, Dong F, Xu J,
Zheng Y. Sorption, degradation and
bioavailability of oxyfluorfen in
biochar-amended soils. Sci Total
Environ. 2019;:87-94
[51] Chen Y, Lan T, Li J, Yang G,
Zhang K, Hu D. Effects of biochar
produced from cornstalk, rice husk and
bamboo on degradation of flumioxazin
in soil. Soil Sediment Contam: An Int J.
[52] Muter O, Berzins A, Strikauska S,
Pugajeva I, Bartkevics V, Dobele G, et al.
The effects of woodchip-and straw-
derived biochars on the persistence
of the herbicide 4-chloro-2-
methylphenoxyacetic acid (MCPA) in
soils. Ecotoxicology and Environmental
Safety. 2014;:93-100
[53] Yavari S, Sapari NB,
Malakahmad A, Yavari S. Degradation
of imazapic and imazapyr herbicides in
the presence of optimized oil palm
empty fruit bunch and rice husk
biochars in soil. Journal of Hazardous
Materials. 2019;:636-642
[54] Gámiz B, Velarde P, Spokas KA,
Hermosín MC, Cox L. Biochar soil
additions affect herbicide fate:
importance of application timing and
feedstock species. Journal of Agricultural
and Food Chemistry. 2017;:3109-3117
[55] López-Piñeiro A, Peña D,
Albarrán A, Becerra D,
Sánchez-Llerena J. Sorption, leaching
and persistence of metribuzin in
Mediterranean soils amended with olive
mill waste of different degrees of
organic matter maturity. Journal of
Environmental Management.
[56] White PM Jr, Potter TL, Lima IM.
Sugarcane and pinewood biochar effects
on activity and aerobic soil dissipation
of metribuzin and pendimethalin.
Industrial Crops and Products.
[57] Spokas KA, Koskinen WC, Baker JM,
Reicosky DC. Impacts of woodchip
biochar additions on greenhouse gas
production and sorption/degradation of
two herbicides in a Minnesota soil.
Chemosphere. 2009;:574-581
[58] Mendes KF, Hall KE, Spokas KA,
Koskinen WC, Tornisielo VL. Evaluating
agricultural management effects on
alachlor availability: Tillage, green
manure, and biochar. Agronomy.
[59] Tatarková V, Hiller E, Vaculík M.
Impact of wheat straw biochar addition
to soil on the sorption, leaching,
dissipation of the herbicide (4-chloro-2-
methylphenoxy) acetic acid and the
growth of sunflower (Helianthus annuus
L.). Ecotoxicology and Environmental
Safety. 2013;:215-221
[60] Ge X, Cao Y, Zhou B, Wang X,
Yang Z, Li MH. Biochar addition
increases subsurface soil microbial
biomass buft has limited effects on soil
CO2 emissions in subtropical moso
Degradation Process of Herbicides in Biochar-Amended Soils: Impact on Persistence and…
bamboo plantations. Appl Soil Eco.
[61] Khorram MS, Lin D, Zhang Q,
Zheng Y, Fang H, Yu Y. Effects of aging
process on adsorption–desorption and
bioavailability of fomesafen in an
agricultural soil amended with rice hull
biochar. Journal of Environmental
Sciences. 2016;:180-191
[62] Khalid S, Shahid M, Murtaza B,
Bibi I, Naeem MA, Niazi NK. A critical
review of different factors governing the
fate of pesticides in soil under biochar
application. Sci Total Environ.
[63] Sandín-España P, Sevilla-Moran B,
Lopez-Goti C, Mateo-Miranda MM,
Alonso-Prados JL. Rapid
photodegradation of clethodim and
sethoxydim herbicides in soil and plant
surface model systems. Arabian Journal
of Chemistry. 2016;:694-703
[64] Haskis P, Mantzos N, Hela D,
Patakioutas G, Konstantinou I. Effect of
biochar on the mobility and
photodegradation of metribuzin and
metabolites in soil–biochar thin-layer
chromatography plates. International
Journal of Environmental Analytical
Chemistry. 2019;:310-327
[65] Varjani S, Kumar G, Rene ER.
Developments in biochar application for
pesticide remediation: current
knowledge and future research
directions. Journal of Environmental
Management. 2019;:505-513
[66] Zhang P, Sun H, Yu L, Sun T.
Adsorption and catalytic hydrolysis of
carbaryl and atrazine on pig manure-
derived biochars: impact of structural
properties of biochars. Journal of
Hazardous Materials. 2013;
[67] Yang J, Pan B, Li H, Liao S,
Zhang D, Wu M, et al. Degradation of
p-nitrophenol on biochars: role of
persistent free radicals. Environmental
Science & Technology. 2016;:694-700
[68] Zhang P, Sun H, Min L, Ren C.
Biochars change the sorption and
degradation of thiacloprid in soil:
insights into chemical and biological
mechanisms. Environmental Pollution.
[69] Sun K, Keiluweit M, Kleber M,
Pan Z, Xing B. Sorption of fluorinated
herbicides to plant biomass-derived
biochars as a function of molecular
structure. Bioresource Technology.
[70] Shinogi Y, Kanri Y. Pyrolysis of
plant, animal and human waste:
physical and chemical characterization
of the pyrolytic products. Bioresource
Technology. 2003;:241-247
[71] Fernandes BCC, Mendes KF,
Tornisielo VL, Teófilo TMS, Takeshita V,
PSF d C, et al. Effect of pyrolysis
temperature on eucalyptus wood
residues biochar on availability and
transport of hexazinone in soil.
International journal of Environmental
Science and Technology. 2021;:499-514
[72] Martin SM, Kookana RS, Van
Zwieten L, Krull E. Marked changes in
herbicide sorption–desorption upon
ageing of biochars in soil. Journal of
Hazardous Materials. 2012;:70-78
[73] Junqueira LV, Mendes KF,
Sousa RND, Almeida CDS, Alonso FG,
Tornisielo VL. Sorption-desorption
isotherms and biodegradation of
glyphosate in two tropical soils aged
with eucalyptus biochar. Archives of
Agronomy and Soil Science.
[74] Trigo C, Spokas KA, Hall KE, Cox L,
Koskinen WC. Metolachlor sorption and
degradation in soil amended with fresh
and aged biochars. Journal of
Agricultural and Food Chemistry.
[75] Gámiz B, Velarde P, Spokas KA,
Cox L. Dynamic effect of fresh and aged
biochar on the behavior of the herbicide
mesotrione in soils. Journal of
Agricultural and Food Chemistry.
[76] Gámiz B, Velarde P, Spokas KA,
Celis R, Cox L. Changes in sorption and
bioavailability of herbicides in soil
amended with fresh and aged biochar.
Geoderma. 2019a;:341-349
[77] Cabrera A, Cox L, Spokas KURT,
Hermosín MC, Cornejo J,
Koskinen WC. Influence of biochar
amendments on the sorption–
desorption of aminocyclopyrachlor,
bentazone and pyraclostrobin
pesticides to an agricultural soil. Sci
Total Environ. 2014;:438-443
[78] Yang Y, Sheng G, Huang M.
Bioavailability of diuron in soil
containing wheat-straw-derived char.
Sci Total Environ. 2006;:170-178
[79] Xu C, Liu W, Sheng GD. Burned rice
straw reduces the availability of
clomazone to barnyardgrass. Sci Total
Environ. 2008;:284-289
[80] Graber ER, Tsechansky L, Gerstl Z,
Lew B. High surface area biochar
negatively impacts herbicide efficacy.
Plant and Soil. 2012;:95-106
[81] Genesio L, Miglietta F, Baronti S,
Vaccari FP. Biochar increases vineyard
productivity without affecting grape
quality: Results from a four years field
experiment in Tuscany. Agriculture,
Ecosystems and Environment.
[82] Khorram MS, Zhang G, Fatemi A,
Kiefer R, Mahmood A, Jafarnia S, et al.
Effect of walnut shell biochars on soil
quality, crop yields, and weed dynamics
in a 4-year field experiment.
Environmental Science and Pollution
Research. 2020;:18510-18520
[83] Mendes KF, Furtado IF,
Sousa RND, Lima ADC, Mielke KC,
Brochado MGDS. Cow bonechar decreases
indaziflam pre-emergence herbicidal
activity in tropical soil. Journal of
Environmental Science and Health, Part B.
[84] Chauhan BS. Rice husk biochar
influences seedling emergence of jungle
rice (Echinochloa colona) and herbicide
efficacy. American Journal of Plant
Sciences. 2013;:1345-1350
[85] Clay SA, Krack KK, Bruggeman SA,
Papiernik S, Schumacher TE. Maize,
switchgrass, and ponderosa pine
biochar added to soil increased
herbicide sorption and decreased
herbicide efficacy. J Environ Sci Health
Part B. 2016;:497-507
[86] Soni N, Ferrell JA, Devkota P,
Mulvaney MJ. Biochar Effects on Weed
Management. Vol. 3. Florida, EUA: UF/
IFAS Extension University of
Florida; 2021
... For example, the application of biochar in the soil is strongly correlated with herbicide degradation processes [84]. The authors stated that if the goal is to apply the herbicide in pre-emergence after adding biochar to the soil, caution should be taken as biochar can either decrease or increase the persistence of the chemical, affecting weed control efficacy over time. ...
Full-text available
Herbicides play a crucial role in weed control in various agricultural and non-agricultural settings. However, their behavior in the environment is complex and influenced by multiple factors. Understanding their fate and retention, transport, and transformation is essential for effective herbicide management and minimizing their impact on ecosystems. This chapter begins by emphasizing the importance of studying herbicide behavior in real-world conditions, considering physical, chemical, and biological amendments in soil. It highlights how these amendments can directly affect weed control efficacy when residual herbicides are applied in pre-emergence. Detailed knowledge of herbicide behavior in the environment enables the adjustment of application rates based on soil type and climatic conditions, which is a key aspect of precision agriculture. The study of herbicide interactions in the environment has experienced significant growth across various subfields, particularly in the last three decades. It can be considered a multidisciplinary subject that encompasses areas such as agricultural, environmental, and biological sciences, as well as technology, physics , chemistry, and biomedicine. Overall, there are over 35,000 papers on herbicide behavior in the environment, and the trend indicates that the number of publications will continue to grow in the coming years.
... As per some investigations, biochar has a composite structure composed of amorphous organic matter, inorganic minerals, and crystalline organic matter (20). The surface is covered by inorganic minerals with a high cation exchange capacity, similar to clay minerals, and the concentration of free OH-in the solu-tion rises, as does the pH of the system (21), which might hasten the hydrolysis of organophosphorus pesticides (22) and carbamate pesticides (23). If biochar was aged for two years, the immobilization impact on triazine pesticides (simazine) did not alter significantly, indicating that biochar use is ongoing (24). ...
Full-text available
Biochar is a porous carbon-rich substance generated by anoxic pyrolysis of biomass. Biochar has a high adsorption capacity for organic contaminants in water and soil environmental media due to its large specific surface area and surface physical and chemical characteristics. The effects of biochar application on the adsorption-desorption behavior and bioavailability of pesticides in soil are illustrated in this paper; biochar can strongly adsorb pesticides in soil due to its loose and porous properties, large specific surface area and surface energy, and highly aromatic structure. Residual pesticide pollutants are reduced, as is desorption hysteresis, which reduces pesticide desorption. Furthermore, the use of biochar reduced the absorption and efficacy of pesticides in soil. At the same time, it describes the present gaps in research on the influence of biochar on pesticide migration mechanisms and its application in pesticide pollution control, and it identifies the major scientific issues that need to be addressed. Finally, the potential application of biochar in pesticide pollution management is discussed.
... For this reason, fomesafen half-life values in diverse soil types ranged variably from 4 to 66 d (Li et al. 2019;Mueller et al. 2014). Pumpkin injury inconsistency across trials was possibly due to its variable persistence depending on soil characteristics and other environmental factors such as microbial degradation (Feng et al. 2012;Mielke et al. 2022) and rainfall pattern. PPAC-2021 had the most prolonged injury (Table 2), probably because there could have been more available herbicide as a result of less leaching. ...
Full-text available
Three dose-response trials were performed in 2020 and 2021 at two Indiana locations: the Southwest Purdue Agricultural Center (SWPAC) and the Pinney Purdue Agricultural Center (PPAC), to determine the tolerance of two Jack O’Lantern pumpkin cultivars to fomesafen applied preemergence. The experiment was a split-plot arrangement in which the main plot was the fomesafen rate (0, 280, 560, 840, and 1,220 g ai ha ⁻¹ ), and the subplot was the pumpkin cultivar ('Bayhorse Gold’ and 'Carbonado Gold'). As the fomesafen rate increased from 280 to 1,120 g ha ⁻¹ , the predicted pumpkin emergence decreased from 85 to 25% of the non-treated control at SWPAC-2020, but only from 99 to 74% at both locations in 2021. The severe impact on emergence at SWPAC-2020 was attributed to rainfall. Visible injury included bleaching and chlorosis due to the herbicide splashing from the soil surface onto the leaves and included stunting, but injury was transient. As the fomesafen rate increased from 280 to 1,120 g ha ⁻¹ , the predicted marketable orange pumpkin yield decreased from 95 to 24% of the non-treated control at SWPAC-2020 and 98 to 74% at PPAC-2021. Similarly, the predicted marketable orange pumpkin fruit number decreased from 94 to 21% at SWPAC-2020 and 98 to 74% at PPAC-2021. Fomesafen rate did not affect marketable orange pumpkin yield and fruit number at SWPAC-2021 and marketable orange pumpkin fruit weight at any location year. Overall, the fomesafen rate of 280 g ha ⁻¹ was safe for use preemergence in the pumpkin cultivars 'Bayhorse Gold’ and 'Carbonado Gold’ within one day after planting, but there is a risk of increased crop injury with increasing rainfall.
Full-text available
Several benefits of biochar on soil biological and chemical properties are known and demonstrated. Moreover, biochar application has also been discussed as an effective means to remediate soil polluted with toxic compounds as it has the capacity to adsorb the pollutants, especially the organic ones. Pesticides are commonly used in conventional agriculture as plant protection agents but are known to cause environmental hazards with diverse impacts including on the human health. Biochar amendments of soil may stabilize pesticides through sorption and thus reduce their bioavailability, bioaccumulation, biomagnification and ecotoxicity. Some reports found evidence for an increased microbial activity and diversity (after biochar amendment), which play an important role in the biodegradation of pesticides. An understanding of the effect of biochar on the bioavailability of pesticide residues in soil and biochar-microbe-pesticide interactions are necessary to explore the potential of biochar in pesticide-contaminated soils. Here we review the impact of biochar application on soil properties, microbial communities and pesticides, also highlighting future directions of research for biochar as a soil amendment for remediation of contaminated soils.
Full-text available
The anthropogenic origin of the Amazonian dark earths (Terra Preta de Índio) was first verified more than 70 year ago. However, the last 30 years have seen a massive wave of scientific investigation, public interest and an ever-expanding intensification of commercial activity toward all things connected to “Terra Preta.” Today, the dominant concept, which drives current research, is that of binding atmospheric carbon with artificially concocted dark earths. The large-scale production of Terra Preta is said to be an effective tool in efforts to mitigate global warming. This text attempts to provide a history of the knowledge on Amazonian dark earths. It not only focuses on scientific aspects but also considers traditional indigenous knowledge. The position is taken that without indigenous knowledge, modern Terra Preta research would not exist; a view, which has profound implications for the ethical evaluation of all further, applied Terra Preta Nova research and commercial endeavors.
Full-text available
Herbicides are the most consumed pesticides worldwide, their interaction with soil and plants changes their availability in the soil solution, affecting soil retention (sorption-desorption) and weed absorption. Therefore, for there to be the efficiency of absorption by plant, it is necessary that the product applied in pre-emergence, be bioavailable in the soil solution, and not form of bound residue or/and sorbed in soil. The herbicide sorption and desorption process refers to the soil's ability to retain and/or dissipate the herbicide molecule, being influenced by various soil properties (soil organic matter [SOM], cation exchange capacity ]CEC], iron and aluminum oxides, texture, and pH) and environmental conditions (rainfall, temperature, and humidity). Given the complexity of controlling the properties involved, studies have often been carried out with radioisotopes conducted in classic laboratory studies (like a batch equilibrium method), guaranteeing fast and high precision results in monitoring of all stages of analysis. Recently, arising from the studies of kinetics for metals and metalloids, and still incipient in the field of study of herbicides, there has been the stirred flow method, which consists of carrying out studies of kinetics through continuous flow reactors, with the objective of investigating chemical reaction kinetics in short intervals. In addition to these techniques, other techniques for assessing herbicide retention in the soil include a bioassay method sensitive plants (very simple) and herbicide evaluated by liquid or gas chromatography. Thus, this chapter will address the most relevant issues involving the techniques used in the sorption and desorption studies of radiolabeled herbicides, as well as seeking to standardize sorption and desorption studies using 14C or 3H.
Full-text available
The introduction of biochar has been extensively tested under short-term greenhouse or field studies mainly in sandy or acidic soils, while its effects on soil properties, crop plants, and weed species especially in neutral or alkaline soils are still not well understood. Therefore, this study focused on relatively long effects of two walnut shell biochars (5 t ha−1) on soil nutrient dynamics, two crop plants (wheat and lentil) growth and developments, and weed growth dynamics over 4 years (2014–2017). Applied biochar added once at the beginning of the experiment while planted crops were supplied with macro-nutrients and sprayed with pesticides according to conventional requirements of the region. Biochars improved soil properties by 10–23% during the first and second years while positive effects of biochars on weed growth were drastically higher (60–78% higher weed density) during the whole period of this study most likely due to increase in bioavailability of nutrient shortly after biochar amendment and indirect positive effects of biochars on soil physical properties as well. Consequently, biochar macro- and micro-nutrient will be utilized by weed plants with higher efficacy compared with crop plants.
This publication provides an overview of the impact of biochar use as a soil amendment on weed management. Written by Neeta Soni, Jason A. Ferrell, Pratap Devkota, and Michael J. Mulvaney, and published by the UF/IFAS Agronomy Department, revised May 2021.
Application of biochar provide a novel approach against organic contaminated soil issues. The objective of this study was to evaluate the effect of biochars amendment on flumioxazin degradation using batch experiments. A simple and accurate pretreatment method coupled with liquid chromatography tandem with mass spectrometry was developed and successfully applied on the assessment trials of the effect of biochar amendment on the degradation of flumioxazin in soil. Three different types of biochar were characterized in terms of the degradation of flumioxazin in soil. The results demonstrated that flumioxazin degraded fast in four nonbiochar soil sample (half-lives of 11.1–20.8 days) but slower in biochar soils (half-lives of 15.4–30.7 days), and the effect varied with the nature of feedstock and pyrolysis temperature. Biochars prepared at 500°C (CB500 and RB500) could remove flumioxazin more effectively than the biochar prepared at 700°C (BB700). In addition, biochar content also affected the remediation. When the biochar content changed, the degradation rate of flumioxazin varied significantly. The degradation of flumioxazin was faster in soil samples with 0.5% cornstalk biochar than those in nonbiochar soil samples. As the biochar content increased, the degradation rate decreased because of the dominant adsorption efficiency. The results in this study support the environmental risk assessment of flumioxazin in soil and provide some guidance for biochar amendment in soil contaminated with flumioxazin.
The addition of carbonaceous material such as cow bonechar to the soil can affect the availability of applied pre-emergent herbicides such as indaziflam. However, how cow bonechar affects the bioavailability of indaziflam is not yet known. The aim of this study was to evaluate the effect of cow bonechar on herbicidal activity of indaziflam on weeds in a tropical soil. Cow bonechar was added homogeneously to top soil, at 1, 2, 5, 10, and 20 t ha-1, in addition to treatment with unamended soil. At 21 days after indaziflam (75 g ha-1) application, injury weed levels, weed species that emerged spontaneously were identified and the weeds present in each sampling unit were collected. Only 1.4 t ha-1 cow bonechar added to soil was enough to reduce the weed injury level by 50%. From the addition of 2 t ha-1 cow bonechar the application of indaziflam was not efficient to weed control, being equivalent to treatments without herbicide application. Eight weed species (3 monocots and 5 dicots) were identified in all treatments. Eleusine indica and Digitaria horizontalis accounted for about 99.7% of the entire infestation of the weed community. Cow bonechar decreases indaziflam pre-emergence herbicidal activity in tropical soil for weed control, most likely due to the high sorption and unavailability of the product in the soil solution.
Biochar is a material with the ability to adsorb pollutants, and this capacity depends on pyrolysis temperature. In this research, the effect of pyrolysis temperature (650, 750, 850, and 950 °C) on the properties of biochar derived from eucalyptus wood and its influence on the sorption/desorption, leaching, and distribution of hexazinone in soil were evaluated. Sorption and desorption were investigated using the batch balance method, and experiments were conducted to assess hexazinone leaching (in glass columns) and distribution (in biometric flasks). The pyrolysis temperature of 950 °C increased (nitrogen + oxygen)/carbon and ash ratios and produced a biochar with greater sorption coefficient and less desorption coefficient of hexazinone. The pyrolysis temperature of 650 °C produced an aliphatic material, with less sorption and greater desorption. Biochars produced at pyrolysis temperatures of 850 and 950 °C completely prevented leaching of the herbicide in soil. The total hexazinone unavailable (mineralized + non-extracted residue) in the biochar system produced at pyrolysis temperatures of 850 °C (46%) and 950 °C (49%) was higher compared to that produced at 650 °C (33%) and 750 °C (42%). Despite this, the addition of biochar did not alter hexazinone mineralization but reduced the availability of the product in the environment due to the greater amount of non-extracted residue, thus reducing the risk of environmental contamination by this herbicide.