**Department of Microbiology and Biochemistry, A.P. Agricultural University, Rajendranagar, Hyderabad, Andhra Pradesh, 500030
***National Academy of Agricultural Research Management, Rajendranagar, Hyderabad, Andhra Pradesh, 500030
G.B. Pant University of Agriculture and Technology, Pantnagar, Nainital, Uttar Pradesh, 263145
Present addresses: *ICAR Research Complex for NEH Region, Gangtok, Sikkim
Adsorption of terbutryne (2-methyl thio, 4-ethyl amine, 6-tertiary butyl amine-S-triazine) on five samples of humic acid isolated from soils under forest vegetation in Nainital (tarai) foot-hill) region in Uttar Pradesh is reported. The soils (Mollisols) belong to three different series and were collected from depths varying from 0 to 30 cm. Adsorption was similar for all the samples and agreed with Freundlich and Langmuir isotherms. The corresponding constants, enthalphy and entropy are reported. Desorp-tion of the chemical was only partial, thereby showing fixation. Partial hydrolysis of the herbicide also took place.
Adsorption of herbicide, terbutryne, humic acids, adsorption isotherms
