Temperature and water pressure head effects on the degradation of the diketonitrile metabolite of isoxaflutole in a loamy soil under two tillage systems.
Laboratory studies were conducted to evaluate the effects of temperature and water pressure head on the degradation of the diketonitrile metabolite (DKN) of isoxaflutole during 84d in samples collected in a loamy soil under conventional (CT) and conservation (MT) tillage systems. Soil temperature was the major factor controlling DKN degradation in the two tillage systems. The shortest half-lives (T(1/2)) were measured in the seedbed samples under MT at 25 degrees C and -33cm water pressure head. We found that mouldboard ploughing under CT was responsible for the spatial variability of herbicide degradation properties, whereas under MT herbicide degradation was associated to the vertical distribution of organic matter.
Alletto
Lionel
L
Université de Toulouse-Ecole d'ingénieurs de Purpan, Agronomy Department, 75 voie du TOEC BP 57 611, 31076 Toulouse Cedex 3, France. lionel.alletto@purpan.fr
Benoit
Pierre
P
Bergheaud
Valérie
V
Coquet
Yves
Y
D000327:Adsorption; D000383:Agriculture; D001673:Biodegradation, Environmental; D004463:Ecology / Q000379:methods; D006540:Herbicides / Q000032:analysis*; D006812:Humic Substances; D006874:Hydrostatic Pressure; D007555:Isoxazoles / Q000032:analysis; D009570:Nitriles / Q000032:analysis*; D006109:Poaceae / Q000378:metabolism; D012987:Soil / Q000032:analysis*; D012989:Soil Pollutants / Q000032:analysis*; D013450:Sulfones / Q000032:analysis*; D013696:Temperature
D006540:Herbicides; D006812:Humic Substances; D007555:Isoxazoles; D009570:Nitriles; D012987:Soil; D012989:Soil Pollutants; D013450:Sulfones; C486641:diketonitrile; C415327:isoxaflutole