Humic uptake into plant

Sinha (60,61) has suggested that humic and fulvic acids play a major role in mobilising iron and transporting it from the soil to plant roots. At the normal soil pH it is believed that iron bound by the fulvic acid is partially hydroxylated as Fe(OH)2 (62). These complexes interact with phosphate to give an organicmetallic phosphate which may be taken up by plants (60). It has been suggested that the entire humic-iron-phosphate complex is taken up by the roots of plants and not just the iron and phosphate (60, 63). Jorgensen (64) has observed that soil humates suppress the uptake of Pb2+ into plants it is possible that they will also suppress actinide concentration in plants. 

---