humic acid as an organic substance can bound heavy metals. it is a best way of decreasing the hazardous effect of heavy metals on plants and thereby on humans. a factorial experiment was conducted in a completely randomized design of seven replications. the treatments consisted of three cadmium levels (0, 2 and 4 mgl-1), and three humic acid levels (0, 100, 1000 mgl-1) added to nutrient solutio...