scholarly journals Environmental behaviors of (E)-Pyriminobac-methyl in agricultural soils

2021 ◽  
Author(s):  
Wenwen Zhou ◽  
Haoran Jia ◽  
Lang Liu ◽  
Baotong Li ◽  
Yuqi Li ◽  
...  

Abstract. (E)-Pyriminobac-methyl (EPM), a pyrimidine benzoic acid esters herbicide, has a high potential as weedicide; nevertheless, its environmental behaviors are still not well understood. In this study, we systematically investigated for the first time the adsorption–desorption, degradation, and leaching behaviors of EPM in agricultural soils from five exemplar sites in China (characterized by different physicochemical properties) through laboratory simulation experiments. The EPM adsorption–desorption results were well fitted by the Freundlich model (R2 > 0.9999). In the analyzed soils, the Freundlich adsorption (i.e., Kf-ads) and desorption (i.e., Kf-des) coefficients of EPM varied between 0.85–32.22 mg1−1/n L1/n kg−1 and between 0.78–5.02 mg1−1/n L1/n kg−1, respectively. Moreover, the degradation of EPM reflected first-order kinetics: its half-life ranged between 37.46–66.00 d depending on the environmental conditions, and abiotic degradation was predominant in the degradation of this compound. The mobility of EPM in the five soils varied from immobile to highly mobile. The groundwater ubiquity score ranged between 0.9765–2.7160, indicating that EPM posed threat to groundwater quality. Overall, the results of this study demonstrate the easy degradability of EPM, as well as its high adsorption affinity and low mobility in soils with abundant organic matter content and high cation exchange capacity. Under such conditions, there is a relatively low contamination risk for groundwater systems in relation to this compound. At the same time, due to its slow degradation, EPM has a low adsorption affinity and tends to be highly mobile in soils poor in organic matter content and with low cation exchange capacity. Under such conditions, there is a relatively high contamination risk for groundwater systems in relation to this compound. Overall, our findings provide a solid basis for predicting the environmental impacts of EPM.

2021 ◽  
Author(s):  
Wenwen Zhou ◽  
Haoran Jia ◽  
Lang Liu ◽  
Baotong Li ◽  
Yuqi Li ◽  
...  

Abstract (E)-Pyriminobac-methyl (EPM), a pyrimidine benzoic acid esters herbicide, has a high potential as weedicide; nevertheless, its environmental behaviors are still not well understood. In this study, we systematically investigated for the first time the adsorption–desorption, degradation, and leaching behaviors of EPM in agricultural soils from five exemplar sites in China (characterized by different physicochemical properties) through laboratory simulation experiments. The EPM adsorption–desorption results were well fitted by the Freundlich model (R2 > 0.9999). In the analyzed soils, the Freundlich adsorption (i.e., Kf-ads) and desorption (i.e., Kf-des) coefficients of EPM varied between 0.85–32.22 mg1−1/n L1/n kg−1 and between 0.78–5.02 mg1−1/n L1/n kg−1, respectively. Moreover, the degradation of EPM reflected first-order kinetics: its half-life ranged between 37.46–66.00 d depending on the environmental conditions, and abiotic degradation was predominant in the degradation of this compound. The mobility of EPM in the five soils varied from immobile to highly mobile. The groundwater ubiquity score ranged between 0.9765–2.7160, indicating that EPM posed threat to groundwater quality. Overall, the results of this study demonstrate the easy degradability of EPM, as well as its high adsorption affinity and low mobility in soils with abundant organic matter content and high cation exchange capacity. Under such conditions, there is a relatively low contamination risk for groundwater systems in relation to this compound. Overall, our findings provide a solid basis for predicting the environmental impacts of EPM.


2021 ◽  
Author(s):  
Umrbek Sharipov ◽  
Martin Kočárek ◽  
Miroslav Jursík ◽  
Antonín Nikodem ◽  
Luboš Borůvka

Abstract This study focuses on the assessment of herbicide adsorption and degradation in three soils (Haplic Chernozem, Haplic Fluvisol, and Arenic Regozem) from different agricultural regions of the Czech Republic where sunflower is cultivated. Soil samples were used in laboratory batch sorption and degradation experiments for six herbicides commonly used on sunflower crops. The findings are used to examine the effect of soil and herbicide properties on adsorption and degradation, as well as to determine the possible relation between the two processes. The (Kf) sorption coefficient ranged from 1.07 to 135.37 cm3/n μg1-1/n g-1, and sorption increased in order: dimethenamid-p < pethoxamid < s-metolachlor < flurochloridone < aclonifen < pendimethalin. Sorption of all six herbicides was positively correlated with organic matter content (p < 0. 001), and cation exchange capacity (p < 0.001). pH was negatively correlated with the sorption of all six compounds (p < 0.001). Degradation rates of herbicides ranged from 0. 012 to 0. 048 day-1, which corresponding to (DT50) half-lives between 14 - 57 days respectively. The longer half-lives were always found in Haplic Fluvisol with higher organic matter content. Results showed that both adsorption and degradation of herbicides is mainly controlled by soil organic matter. A negative relationship was found between the sorption coefficient and the rate of degradation. It can be concluded that the Freundlich sorption coefficient (Kf) can be a good predictor for soil degradation of the studied herbicides.


Author(s):  
E. A. Akpa ◽  
O. S. Bello ◽  
D. M. Olim

The aim of this research was to investigate the fertility status of soils under Bamboo (Bambusa vulgaris) in Akamkpa and Odukpani Local Government Areas of Cross River State. Composite soil samples were collected at the depth of 0-15 cm under Bamboo (Bambusa vulgaris) using soil auger from fourteen (14) locations. The soil samples were analysed for some physico-chemical properties using standard procedures. Results obtained showed that the soils were predominantly sandy loam in both Akamkpa and Odukpani with a significant difference in the soil pH which was very strongly acid (mean pH in water =5.0). Organic carbon was high (26.00–41.00 g/kg) in Akamkpa and Odukpani (24.00 – 41.00 g/kg). Total nitrogen was medium (2.4–4.9 g/kg) in Akamkpa and low to medium (0.19 – 0.33%) in Odukpani. Available phosphorus was generally low (1.8-2.9 mg/kg) and (1.88 – 6.63 mg/kg) in both areas. Exchangeable calcium was low to medium (3.6-7.4 cmol/kg) in Akamkpa and medium to high (5.6-14.8 cmol/kg) in Odukpani. Magnesium contents were low (0.8-6.7 cmol/kg) and high (0.4 – 12.4 cmol/kg) in both areas. While exchangeable potassium (0.08 – 0.13 cmol/kg) and (0.09 – 0.13 cmol/kg) with sodium contents (0.06 – 0.08 cmol/kg) and (0.06 – 0.10 cmol/kg) were low. Exchangeable acidity of hydrogen (0.1 – 3.7 cmol/kg) was high in Akamkpa and low to medium (0.08-2.32 cmol/kg) in Odukpani and that of Aluminum contents (0.3 – 4.0 cmol/kg) and (0.0 – 4.0 cmol/kg) were generally low. The cation exchange capacity (CEC) was low (4.5 – 11.4 cmol/kg) in Akamkpa and low to medium (7.2 – 24.01 cmol/kg) in Odukpani and those of Effective Cation Exchange Capacity (ECEC) was low to medium (9.2 – 15.9 cmol/kg) in Akamkpa but low and high (7.8 – 24.41 cmol/kg) in Odukpani. The Base Saturation was medium to high (37 – 96%) in Akamkpa and high (60.9 – 98.4%) in Odukpani. The studies revealed that soils under Bamboo had high organic matter content. This could be attributed to the bamboo leaf fall which enhances the increase of organic matter content.


Weed Science ◽  
1970 ◽  
Vol 18 (4) ◽  
pp. 470-474 ◽  
Author(s):  
L. C. Liu ◽  
H. Cibes-Viadé ◽  
F. K. S. Koo

The adsorption of 2-(ethylamino)-4-(isopropylamino)-6-(methylthio)-s-triazine (ametryne) and 3-(3,4-dichlorophenyl)-1,1-dimethylurea (diuron) varied greatly among 34 Puerto Rican soils was studied using the agitated slurry technique. Adsorption was expressed as a distribution coefficient (Kd), which is the ratio of the amount of herbicide adsorbed to the amount in the equilibrium solution. In general, diuron was adsorbed to a greater degree than ametryne. Adsorption of ametryne was positively correlated with organic matter and silt content but negatively correlated with pH of the soil. The inclusion of soil pH in a multiple regression analysis contributed the highest increase in explanation for adsorption of ametryne. Adsorption of diuron was highly correlated with organic matter content and cation exchange capacity. A correlation was found between adsorption of diuron and content of magnesium, and soil texture. Cation exchange capacity was the only inclusion soil property which, in addition to organic matter, significantly contributed to the adsorption of diuron. Temperature appeared to have a greater effect on the adsorption of diuron than on the adsorption of ametryne. Conversely, the effect of pH on the adsorption of ametryne was significantly greater than that of diuron.


2016 ◽  
Vol 8 (2) ◽  
pp. 229-235
Author(s):  
A. F. M. Sanaullah ◽  
M. Akhtaruzzaman ◽  
M. A. Uddin

Soil samples were collected from M. R. Khan tea-estate area of Moulvibazar district, Bangladesh. Organic matter, active acidity, reserve acidity, cation exchange capacity, clay content and textural class of the collected soil samples for different topographic positions and depths were determined. The percentage of sand, silt and clay varied from 59.75 to 70.50, 12.50 to 20.00 and 14.50 to 22.75, respectively. Active acidity and reserve acidity of the soils varied from 4.13 to 5.82 and 3.46 to 4.84, respectively.  Organic matter content varied from 0.37% to 1.93%. Cation exchange capacity (CEC) varied from 11.42 to 24.86 cmolKg-1. Soils were acidic in nature with considerably high reserve acidity. The measured parameters of the soil samples were plotted and analyzed with reference to topography and depth. The parameters have been found to vary with sampling sites, depths and topography.


1969 ◽  
Vol 57 (4) ◽  
pp. 286-293 ◽  
Author(s):  
L. C. Liu ◽  
H. R. Cibes-Viadé

The adsorption capacity of Fluometuron, Prometryne, Sencor, and 2,4-D by 48 local soils was determined spectrophotometrically. The mean adsorptivities of the four herbicides by these soils were as follows: Prometryne 37.0 percent, Sencor 23.0 percent, Fluometuron 22.6 percent, and 2,4-D 12.4 percent. The results indicated that organic matter content was the factor most highly correlated with adsorption of these herbicides by the 48 soils. Cation exchange capacity was found to correlate significantly with adsorption of Fluometuron, Prometryne, and Sencor. Such was not the case with 2,4-D. Correlation between clay content and adsorption of Fluometuron and Sencor was statistically significant. In contrast, no significant correlation was noted between clay content and adsorption of Prometryne and 2,4-D.


Sign in / Sign up

Export Citation Format

Share Document