scholarly journals Adsorption and Degradation Behavior of Six Herbicides in Different Agricultural Soils.

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.

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.


2016 ◽  
Vol 2 (2) ◽  
pp. 37
Author(s):  
B.H. Prasetyo ◽  
N. Suharta ◽  
Subagyo H. ◽  
Hikmatullah Hikmatullah

Ultisols are a major group of marginal soils extensively found in the upland area of Indonesia. To better understand the potential of the Ultisols developed from claystone and sandstone in the Sasamba Integrated Economical Development Area in East Kalimantan, chemical and mineralogical characteristics of 27 Ultisols pedons consisting of 76 topsoil and 118 subsoil samples were investigated. Besides analysis and interpretation of data, relationships of several soil characteristics were constructed using simple regression. The results indicated that Ultisols showed acid to very acid reaction, had low content of organic matter and low base saturation. Soils generally exhibited net negative charge, and the point of zero charge was reached at pH 3.6. Both potential and available phosphates were low, and there was a trend that amorphous aluminum was responsible for phosphate fixation. The low content of exchangeable potassium in topsoil and subsoil indicated a positive correlation with potential potassium. Clay mineral was composed chiefly of kaolinite, with small amounts of illite, vermiculite, and quartz. The domination of kaolinite and low organic matter content causes the soils to have low cation exchange capacity. Soil management in this area should be focused on building up and maintaining soil fertility, and applying appropriate soil conservation techniques to minimize erosion. To obtain sustained productivity, various soil amendments including the use of farm and/or green manure, liming with agricultural lime, and application of rock phosphate and K fertilizers were highly recommended.


2008 ◽  
Vol 53 (No. 5) ◽  
pp. 225-238 ◽  
Author(s):  
N. Finžgar ◽  
P. Tlustoš ◽  
D. Leštan

Sequential extractions, metal uptake by <i>Taraxacum officinale</i>, Ruby&rsquo;s physiologically based extraction test (PBET) and toxicity characteristic leaching procedure (TCLP), were used to assess the risk of Pb and Zn in contaminated soils, and to determine relationships among soil characteristics, heavy metals soil fractionation, bioavailability and leachability. Regression analysis using linear and 2nd order polynomial models indicated relationships between Pb and Zn contamination and soil properties, although of small significance (<i>P</i> < 0.05). Statistically highly significant correlations (<i>P</i> < 0.001) were obtained using multiple regression analysis. A correlation between soil cation exchange capacity (CEC) and soil organic matter and clay content was expected. The proportion of Pb in the PBET intestinal phase correlated with total soil Pb and Pb bound to soil oxides and the organic matter fraction. The leachable Pb, extracted with TCLP, correlated with the Pb bound to carbonates and soil organic matter content (<i>R</i><sup>2</sup> = 69%). No highly significant correlations (<i>P</i> < 0.001) for Zn with soil properties or Zn fractionation were obtained using multiple regression.


1998 ◽  
Vol 131 (4) ◽  
pp. 455-464 ◽  
Author(s):  
B. J. CHAMBERS ◽  
T. W. D. GARWOOD

Lime loss rates were determined for 11 agricultural soils across England (1987–92) under arable cropping (six sites) and grassland management (five sites), receiving commercial rates of fertilizer inputs. Lime additions in the range 0–1500 kg ha−1 CaCO3 (250 kg ha−1 CaCO3 increments) were made annually to the sites. Soil pH (water and 0·01 m CaCl2) and exchangeable calcium concentrations were measured annually. The annual lime loss rates were calculated as the amount of lime needed to maintain the initial site pH or exchangeable Ca concentrations.Lime loss rates based on soil water pH varied between 40 and 1270 kg ha−1 CaCO3, on the basis of CaCl2 pH between 0 and 1370 kg ha−1 CaCO3, and exchangeable Ca between 0 and 1540 kg ha−1 CaCO3. There was a positive relationship between the lime loss rate (based on water pH) and initial soil pH value (r=0·75; P<0·01), and a negative relationship with soil organic matter content (r=0·63; P<0·05) was based on soil pH, organic matter content and nitrogen (N) fertilizer input. Lime loss rates were approximately double those predicted by previous models developed in the 1970s, reflecting the greater quantities of inorganic N fertilizer now being applied to agricultural land.


Soil Research ◽  
2012 ◽  
Vol 50 (1) ◽  
pp. 7 ◽  
Author(s):  
Thomas Keller ◽  
Anthony R. Dexter

The plastic limits (lower plastic limit, PL; and liquid limit, LL) are important soil properties that can yield information on soil mechanical behaviour. The objective of this paper is to study the plastic limits of agricultural soils as functions of soil texture and organic matter (OM) content. The plastic limits were highly related to the clay content. The LL was more strongly correlated with clay than was PL, but the reasons are unclear. Interestingly, PL was virtually unaffected by clay content for soils with clay contents below ~35%. The OM had a strong effect on the plastic limits. This effect was clearly demonstrated when analysing soils of similar texture with a range of OM. We present equations (pedotransfer functions) for estimation of PL, LL, and plasticity index (PI) from soil texture and OM. Finally, we predict that the clay content must be ≥10% for soils without OM to be plastic; however, soils with <10% clay can be plastic if OM is present. More research is needed to investigate OM effects on soil consistency.


1970 ◽  
Vol 20 (2) ◽  
pp. 173-182
Author(s):  
KF Akhter ◽  
ZH Khan ◽  
MS Hussain ◽  
AR Mazumder

The seasonally flooded soils of Bangladesh are unique in respect of several specific characteristics and contribute toward producing bulk of its staple food - mainly rice. Having fine texture these soils are similar to the “paddy soils” of Southeast Asian floodplains and have high production potential under proper management. Six representative soil series, viz. Arial, Debidwar, Naraibag, Jalkundi, Siddirganj and Tippera from the central region of Bangladesh have been studied to evaluate some of their intrinsic physico-chemical properties and their sustainable management requirements. These soils are slightly acidic to neutral and are negatively charged with ΔpH values ranging between –0.2 and –1.2. The organic matter content in the surface soil is relatively low that decreases steadily with depth. The cation exchange capacity (CEC) of the soils varies on the basis of their clay and organic matter contents while base saturation per cent (BSP) is high. The contents of available N, P, K and S and DTPA-extractable Fe, Mn, Cu and Zn in soils are moderate and are commensurate with the contents of colloidal fractions. These soils receive several mineral nutrients annually with the sediments deposited during the monsoon floods. The characteristics like organic matter content, particle size distribution, CEC, pH and BSP that have important management implications have been discussed. Key words: Seasonally flooded soils; Physical and chemical attributes; Management implications DOI: http://dx.doi.org/10.3329/dujbs.v20i2.8978 DUJBS 2011; 20(2): 173-182


2018 ◽  
Vol 7 (5) ◽  
pp. 386-395 ◽  
Author(s):  
Abdellah El Boukili ◽  
Nidae Loudiyi ◽  
Ahmed El Bazaoui ◽  
Abderrahim El Hourch ◽  
M'Hamed Taibi ◽  
...  

The present study was conducted in order to investigate the adsorption and desorption behavior of Mefenpyr-diethyl (MFD) using the batch equilibration technique in four soils, with different ranges of organic matter content, from different regions of Morocco orders of Benimellal (Soil 1), Settat (Soil 2), Sidi Bettach (Soil 3) and EL Hajeb (Soil 4). The adsorption isotherm models Langmuir, linear and Freundlich were used to compare the adsorption capacity of the soils. The results indicated that the Freundlich equation provided the best fit for all adsorption data. The values of KF and Kd ranged from 4.45 to 15.9 and 4.30 to 18.30 L.kg-1 , respectively. The calculated total percentage of desorption values from the Soil 1, Soil 2, Soil 3 and Soil 4 after the four desorption process were 59 %; 55,6 %; 37,5 % and 52,5%, respectively. Highest adsorption and desorption were observed in soil 1, and the lowest was in soil 3. According to the adsorption and desorption results, organic matter and clay seemed to be the most important factors influencing the adsorption capacity of MFD.


Weed Science ◽  
1994 ◽  
Vol 42 (4) ◽  
pp. 629-634 ◽  
Author(s):  
Blake A. Brown ◽  
Robert M. Hayes ◽  
Donald D. Tyler ◽  
Thomas C. Mueller

Fluometuron adsorption and degradation were determined in soil collected at three depths from no-till + no cover, conventional-till + no cover, no-till + vetch cover, and conventional-till + vetch cover in continuous cotton. These combinations of tillage + cover crop + soil depth imparted a range of organic matter and pH to the soil. Soil organic matter and pH ranged from 0.9 to 2.5% and from 4.7 to 6.5, respectively. Fluometuron adsorption was affected by soil depth, tillage, and cover crop. In surface soils (0 to 4 cm), fluometuron adsorption was greater in no-till + vetch plots than in conventional-tilled + no cover plots. Soil adsorption of fluometuron was positively correlated with organic matter content and cation exchange capacity. Fluometuron degradation was not affected by adsorption, and degradation empirically fit a first-order model. Soil organic matter content had no apparent effect on fluometuron degradation rate. Fluometuron degradation was more rapid at soil pH > 6 than at pH ≤ 5, indicating a potential shift in microbial activity or population due to lower soil pH. Fluometuron half-life ranged from 49 to 90 d. These data indicate that tillage and cover crop may affect soil dissipation of fluometuron by altering soil physical and chemical properties that affect fluometuron degrading microorganisms or bioavailability.


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