open access

https://hdl.handle.net/2115/66280

Adsorption and retarded transport of nitrate in Andisol subsoils caused by the apparent salt sorption

日本語

火山灰土壌

2011-04-05

一般社団法人 日本土壌肥料学会

Japanese Journal of Soil Science and Plant Nutrition

82(2)

114-122

Adsorption and retarded transport of nitrate (NO_3^-) was studied using 9 Andisol subsoils in Japan. In all the soils investigated, NO_3^- adsorption in the NO_3^- concentration of 0-14mM was caused almost exclusively by the apparent salt sorption, the simultaneous adsorption of equivalent amounts of cations and anions, and was not accompanied by the desorption of indigenous sulfate through anion exchange. The NO_3^- adsorption was approximated by a linear adsorption isotherm with the distribution coefficient, K_d, ranging from 0.3 to 1.6L kg^<-1>, which suggests that 25 to 70% of NO_3^- in the subsoils were in the adsorbed phase. Nitrate transport in repacked soil columns showed increasing delay of NO_3^- breakthrough with the increase in K_d. Retardation factor, R, obtained by fitting the convection-dispersion model to the experimental NO_3^- breakthrough curves ranged from 1.3 to 3.2, and was in close agreement with that estimated from K_d for each soil. These results suggest that, in the absence of preferential flow, NO_3^- travel distance is 0.3 to 0.8 times that of water flow, and can be predicted using K_d obtained from batch adsorption experiments.

学術雑誌論文

Version of Record

0029-0610

AN00195767