Environmental Engineering Reference
In-Depth Information
TABLE 6.2 (Continued)
Chemical Classiication of Pesticides
Chemical Type
Example
Structure
Typical Action
Thiocyanates
Lethane60
Insecticide
O
OCH 2 CH 2 SCN
CH 3 (CH 2 ) 10 C
Phenols
Dinitrocresol
Insecticide
NO 2
O 2 N
O
Na
CH 3
Formamides
Chlordimeform
Insecticide
Insecticide
Cl
N
CH
N(CH 3 ) 2
CH 3
TABLE 6.3
Factors Inluencing the Persistence of Pesticides in Soil
Experimental
Variables
Pesticide
Soil/Site
Climate
Chemicalnature
Volatility
Solubility
Formulation
Concentration
Application
Method
Time(ofyear
andday)
FrequencyAmount
Site
•Elevation,slope,aspect,geographical
location
•Plantcover(species,density,
distribution,historyatsite)
•Fauna(species,density,distribution,
historyatsite)
•Microbialpopulations(speciesdensity,
distribution,historyatsite)
•Useof“fertilizers,”lime,mulches,and
greenmanures
•Useofotherpesticidesandchemicals
•Tillage,cultivation,drainage,irrigation
(type,depth,amount,timing,frequency)
•Fire(e.g.,burningofcropresidues)
•Adjacentenvironments(hedges,ield
borders,woodlots,waterbodies)
•Presenceofpollutants
Wind,air
movements
Temperature,solar
radiation
Rainfall,relative
humidity,
evaporation
Plotsize,arrangement
Numberofreplicates
Frequencyof
sampling
Samplesize,shape
Techniquesfor
measuringvariables
Soiltype
•Texture,especiallyclaycontent
•Structure,compaction
•Organicmatterandhumuscontents
•Soilmoisture,leaching
•pH
•Mineralioncontent
Source:
FromArias-Estévez,M.,López-Periago,E.,Martínez-Carballo,E.,Simal-Gándara,J.,Mejuto,J.-C.,and
García-Río,L.2008.Themobilityanddegradationofpesticidesinsoilsandthepollutionofgroundwater
resources. Agric. Ecosyst. Environ .123:247-260.
 
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