As the p H of soi l from BSES was>7.0,diet h yl en et ri a m i n ep e n t a a a c e t i c a c i d ( D T P A ) w a s u s e d t o e x t r a c t C d f r o m s o i l s a m p l e s ,
wi th a s oi l t o s ol u ti on o f 1 t o 2 a n d a r e a c t io n ti m e o f 2 h . T h e e x t ra c tin g s ol u t io n c on s i s te d o f 0 . 00 5 M D T P A, 0 . 0 1 M Ca Cl2, and 0.01 M
triethanolamine (TEA) adjusted to pH 7.3. This was performed by a
modification of the method of Lindsay and Norvell (1978)