Agricultural-Based Food Production Geoenvironment Stressors - Sustainable Practices in Geoenvironmental Engineering - page 186

metolachlor (C 15 H 22 ClNO 2 ), cyanazine (C 9 H 13 ClN 6 ), alachlor (C 14 H 20 ClNO 2 ), and EPTC
( S -ethyl dipropylthiocarbamate, C 9 H 9 NOS), are the most commonly detected chemicals—
correlating well with their usage (USGS, 1999). Frequent pesticide and fertilizer use can alter
the natural resistance of the plants and may also increase their resistance to parasites.
This will make some soils unusable for agricultural purposes. Levels of contaminants
typically found in agricultural areas are shown in Tables 6.1 and 6.2. From 2000 to 2007,
the application of pesticides has decreased from 0.54. to 0.5 billion pkg (USEPA, 2006,
2007), and 80% is used for agriculture. Overall, more than 2.3 million tonnes of pesti-
cides (22% of the world use) are applied—resulting in the pollution of more than 10% of

TABLE 6.1
Levels of Contaminants in Agricultural Areas

Contaminant Streams Shallow Groundwater

Nitrogen Medium to high High

Phosphorus Medium to high Low

Herbicides Low to high Medium to high

Currently used insecticides Low to medium Low to medium

Insecticides used in the past Low to high Low to high

Source: Adapted from USGS, The Quality of Our Nation's Waters—Nutrients and Pesticides. U.S.
Geological Circular 1225, 1999. Available at http://water.usgs.gov.

TABLE 6.2
Frequency of Detection of Herbicides and Insecticides in Streams and Groundwater in
Agricultural Lands as a Percentage of Samples
Pesticide Streams Groundwater

Agricultural
Atrazine

65 30

Deethylatrazine 35 29

Metaloalachlor 53 8

Cyanazine 25 2

Alachlor 28 2

EPTC 12 1

Urban herbicides
Simazine

44 12

Prometon 26 10

2,4-D 11 1

Diruron 7 2

Tebuthiuron 7 1

Insecticides
Diazinon 10 1

Carbaryl 6 <1

Malathion 4 <1

Chlorophirofos 10 <1

Source: Adapted from USGS, The Quality of Our Nation's Waters—Nutrients and Pesticides. U.S.
Geological Circular 1225, 1999. Available at http://water.usgs.gov.