title: Behavior and fate of chlorpyrifos introduced into soil-crop systems by irrigation.
abstract: The effect of chlorpyrifos added in irrigation water to a red soil from Central South China on the growth of wheat and oilseed rape seedlings, together with its uptake, was studied in a pot experiment. Addition of chlorpyrifos (1-10 microg g-1) in a single irrigation with distilled water resulted in absorption of chlorpyrifos by wheat (0.257-4.50 microg g-1) and also oilseed rape seedlings (0.249-2.02 microg g-1) during 20 d of plant growth. An initial concentration of chlorpyrifos in soil that is equivalent to or below 10 microg g-1 did not significantly influence the growth of wheat seedlings. Similarly, an initial concentration equivalent to or below 5 microg g-1 did not significantly influence the growth of oilseed rape seedlings. The degradation rate of chlorpyrifos was 1.4-4.2 times larger in oilseed rape rhizosphere soil than in unvegetated soil. The numbers of bacteria and fungi in oilseed rape rhizosphere soil were 3.18 times and 1.84 times larger, respectively, than those in unvegetated soil. This helps to explain the difference in degradation rates obtained.
authors.affiliation: Institute of Soil Science, Chinese Academy of Sciences (CAS), Nanjing 210008, PR China. lgwang0827@yahoo.com.cn
authors.forename: Ligang
authors.initials: L
authors.lastname: Wang
authors.forename: Xin
authors.initials: X
authors.lastname: Jiang
authors.forename: Dongyun
authors.initials: D
authors.lastname: Yan
authors.forename: Jinshui
authors.initials: J
authors.lastname: Wu
authors.forename: Yongrong
authors.initials: Y
authors.lastname: Bian
authors.forename: Fang
authors.initials: F
authors.lastname: Wang
mesh_terms: D001673:Biodegradation, Environmental; D004390:Chlorpyrifos / Q000032:analysis* / Q000378:metabolism; D018556:Crops, Agricultural / Q000254:growth & development / Q000378:metabolism*; D012987:Soil / Q000032:analysis*; D012989:Soil Pollutants / Q000032:analysis* / Q000378:metabolism; D014908:Triticum / Q000254:growth & development / Q000378:metabolism
chemical_list: D012987:Soil; D012989:Soil Pollutants; D004390:Chlorpyrifos