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

Abstract 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 NH4OAc pH 7.00, and M CaCl2; for corn by N HCl and N NH4OAc pH 7.00; for land spinach by N HNO3, N HCl, Buffered DTPA, N NH4OAc pH 7.00, and M CaCl2; for napier grass by N HCl and Unbuffered DTPA. N HNO3 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 NH4OAc pH 7.00 by amaranth, corn and land spinach, and M CaCl2 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