The correlation study of several chemical extractants to assess plant copper uptake from tropical soils polluted with heavy metals

Glass-house experiments were conducted to study the correlation between Cu uptake by several plants and soil Cu extracted by several chemical extractants. Heavy-metal contaminated soils from Lampung, the southern part of Sumatra, Indonesia, with different levels of Cu were used. Eight different plants including amaranth ( Amaranthus tricolor ), caisim ( Brassica chinensis var. Parachinensis ), corn ( Zea mays L.), land spinach ( Ipomoea reptans Poir ), lettuce ( Lactuca sativa ), napier grass ( Penissetum purpureum ), thorny amaranth ( Amaranthus spinosus L.) and water spinach ( Ipomoea aquatica ) were employed. The uptake of Cu for amaranth is well predicted by N HCl, Buffered DTPA pH 7.30, N NH 4 OAc pH 7.00, and M CaCl 2 ; for corn by N HCl and N NH 4 OAc pH 7.00; for land spinach by N HNO 3 , N HCl, Buffered DTPA, N NH 4 OAc pH 7.00, and M CaCl 2 ; for napier grass by N HCl and Unbuffered DTPA. N HNO 3 is good in predicting the uptake of Cu by land spinach, N HCl by amaranth, corn, land spinach, and napier grass; Buffered DTPA by amaranth and land spinach; Unbuffered DTPA by napier grass; N NH 4 OAc pH 7.00 by amaranth, corn and land spinach, and M CaCl 2 by amaranth and land spinach. None of the tested methods is good in predicting the uptake Cu by caisim, lettuce, thorny amaranth, and water spinach