Sorption of atrazine and ametryn by carbonatic and non-carbonatic soils of varied origin

作者：Kasozi G N; Nkedi Kizza P^*; Lib Y; Zimmerman A R

来源：Environmental Pollution, 2012, 169: 12-19.

DOI：10.1016/j.envpol.2012.05.002

• s-Triazines
• Carbonatic soils
• Calcareous
• Oxisols
• Uganda
• Spodosols
• Organic matter

Sorption of two s-triazines, atrazine and ametryn, by carbonatic soils. Histosols, Spodosols and Oxisols was examined. Linear isotherms were observed and sorption coefficients (K-d) of both compounds were significantly lower (alpha = 0.05) onto carbonatic soils compared to non-carbonatic soils. Furthermore, among carbonatic soil types, the marl-carbonatic soils had the lowest sorption affinities. K-d and organic carbon content were highly correlated, suggesting predominant influence of organic carbon in the sorption of the s-triazine, except in Oxisols and Spodosols where variations suggest other factors. Upon removal of organic matter (OM) using sodium hypochlorite and hydrogen peroxide, the K-d values were reduced by similar to 90%, indicating minimal contribution of mineral surfaces. Thus OM compositional differences likely explain the large variation in s-triazine sorption within and between soil orders. This study highlights the need to consider OM composition in addition to quantity when determining pesticide applications rates, particularly for carbonatic soils.

• 出版日期2012-10