Impacts of diferent organic amendments on soil degradation and phytotoxicity of metribuzin is a well-researched topic, it is to be used as a guide or framework for your Academic Research.
Purpose Persistence of herbicides in soil is a major concerning world issue due to their negative impacts on environment and human health. Laboratory and bioassay experiments were conducted to evaluate the efects of municipal waste compost (MC) and sheep manure (SM) on metribuzin degradation and phytotoxicity of this herbicide.
Methods In degradation studies, soil samples were mixed separately with amendments at a rate of 2.5% (w/w) and metribuzin at a concentration of 5 mg kg−1 soil was used for fortifcation of selected samples. A liquid extraction method was chosen and fnal extracts were analyzed by HPLC. In bioassay study, the phytotoxic efects of diferent concentrations of metribuzin (0, 0.01, 0.05, 0.1, 0.2, 0.4, 0.8 and 1 mg kg−1 soil) on oilseed rape (Brassica napus L.) were evaluated.
Results The results indicated 88.8% degradation of metribuzin in MC during 120-day period followed by SM recording 72.2%, compared to non-amended soil where 59.8% of metribuzin were removed. The half-life was 119.48 days in non-amended soil as compared to 87.72 and 103.43 days in MC and SM application, respectively. MC was the most efficient treatment to accelerate metribuzin dissipation from the soil. Bioassay results showed that metribuzin residues had a negative
efect on root and shoot biomass of oilseed rape. However, the root parameter was more sensitive than the shoot. Conclusions It could be concluded that application of organic amendments to agricultural soils is an eco-friendly strategy to improve soil conditions and non-target crop protection as well as the removal of herbicide residues from soil environment.
Triazine herbicides are one of the most widely used her-
bicide classes and play a major role in managing the
weed populations in the agricultural production systems.
These herbicides are valued because of their low costs,
moderate persistence, and long season weed control in
agroecosystems; however, the intensive utilization of these
compounds may cause serious risks including environmen-
tal safety, water sources’ pollution (Martinez et al. 2016;
Guillon et al. 2018; Montiel-León et al. 2019) as well as
human, animal, and crop health (Ahsan and Del-Valls
2011; Baranowska et al. 2006; Kroon et al. 2014; Husak
et al. 2016; Mehdizadeh and Gholami Abadan, 2018; Meh-
dizadeh, 2019). Haarstad and Ludvigsen (2007) analyzed
the groundwater next to agricultural felds and found high
quantities of metribuzin herbicide. It was reported that there
is a signifcant relationship between application of this class
of herbicides and cytotoxicity as well as breast cancer (Ket-
tles et al. 1997; Huang et al. 2014). Every year in so many
countries excessive amounts of soil-applied herbicides
are used in agricultural lands; therefore, it seems that the
need to provide safe and efective methods for herbicides
removal and degradation from environment are very crucial.
Nowadays, biological degradation is an important environ-
mentally friendly strategy for detoxifcation and dissipation of herbicides from environment (Zhang and Quiao 2002).
Metribuzin is a soil-applied highly water-soluble herbicide
for the control of many broad-leaved and grass weeds in
soya beans, sugar cane, and cereals (Tomlin 2000; Henriksen
et al. 2002). Microbial degradation is the main pathway for
metribuzin degradation from soil environment (Boreen et al.
2003; Lin and Reinhard 2005). Risk assessment of triazine
herbicides needs to estimate their potential for persistence in
environment considering soil components. However, among
soil characteristics, organic matter content is a key factor
that has important efect on herbicide degradation and move-
ment in the soil (Moorman et al. 2001; Gamiz et al. 2017).
Application of organic-based fertilizers can improve edaphic
qualities and change the fate of any herbicide (Majumdar
and Singh 2007; Marín-Benito et al. 2019). However, deter-
mining the behavior of herbicides in soil amended with non-
chemical fertilizers is difcult. Some researchers reported
that the application of organic-based fertilizers under difer-
ent situations increases the herbicide degradation and move-
ment in soil and under other conditions may decrease them
(Singh 2008; Fernandez-Bayo et al. 2009; Kravvariti et al.
2010). The efects of non-chemical fertilizers on removal
and sorption of pesticides have been extensively studied
and diferent results have been reported. Some researchers
found that the application of soil organic amendments could
increase the persistence of herbicides by increasing the sorp-
tion process (Barker and Bryson 2002; Wanner et al. 2005).
Diferent studies showed that the addition of organic mat-
ter including manures, composts, and plant residues to soils
is a widely accepted non-chemical approach for improving
the soil characteristics as well as the diferent crop produc-
tion (Garcia-Gomez et al. 2002; Perez-Murcia et al. 2006;
Bastida et al. 2008; Mehdizadeh et al. 2013; Pampuro et al.
2017a). Cox et al. (2000) concluded that the infertile soils
had a minimum efect on herbicide movement; therefore, the
presence of organic matter can be considered as an important
adsorbent for herbicides.