A degree-day concept for estimating degradation time under field conditions.

Development of degradation rate information for crop protection products in soil is typically a time consuming and costly process. Therefore, development of methodology that would allow extrapolation of limited degradation information to wider field conditions in a predictive fashion would be desirable. This study presents an approach that uses a modified heat unit model to estimate organic compound degradation time using limited datasets. The model requires daily soil or air temperature and volumetric water content. Predictions based on the model for three different compounds in five different field studies were within 80% of measured values based on soil analysis. Results from this research indicate that the model was able to predict compound half-life values across all sites with r2 = 0.99.

[1]  S. Jackson.  Comparison of calculated and measured volumetric water content at four field sites , 2003 .

[2]  G. Soulas,et al.  Modelling of microbial degradation of pesticides in soils , 2001, Biology and Fertility of Soils.

[3]  W. C. Koskinen,et al.  Changes in sorption/bioavailability of imidacloprid metabolites in soil with incubation time , 2001, Biology and Fertility of Soils.

[4]  G. Dinelli,et al.  Comparison of the persistence of atrazine and metolachlor under field and laboratory conditions. , 2000, Journal of agricultural and food chemistry.

[5]  P. Perucci,et al.  Relationship between rimsulfuron degradation and microbial biomass content in a clay loam soil , 2000, Biology and Fertility of Soils.

[6]  Alison M. Cupples,et al.  Effect of Soil Conditions on the Degradation of Cloransulam-Methyl , 2000 .

[7]  R. Bromilow,et al.  Factors affecting degradation rates of five triazole fungicides in two soil types: 1. Laboratory incubations , 1999 .

[8]  R. Kookana,et al.  Degradation rates of eight pesticides in surface and subsurface soils under laboratory and field conditions , 1998 .

[9]  T. Gish,et al.  Persistence of seven pesticides as influenced by soil moisture1 , 1996 .

[10]  W. Inskeep,et al.  Soil Depth and Temperature Effects on Microbial Degradation of 2,4-D , 1996 .

[11]  Kate M. Scow,et al.  Effect of diffusion and sorption on the kinetics of biodegradation: Theoretical considerations. (Reannouncement with new availability information) , 1992 .

[12]  L. Holden,et al.  Nonlinear pesticide dissipation in soil: a new model based on spatial variability , 1990 .

[13]  D. Schröder,et al.  Side-effects of sequentially- and simultaneously-applied pesticides on non-target soil microorganisms: Laboratory experiments , 1990 .

[14]  M. Leistra.  Evaluation of rate coefficients for consecutive reactions of pesticides in soil , 1978 .