Effect of various levels of zinc on the uptake of copper and iron by maize (Zea mays L.)

abonos de oligoelementos absorption de substances nutritives analytical methods application rates cobre composition globale copper copper sulphate cuivre dose d'application fer ferrous sulphate fertilisation fertilizer application hierro iron micronutrient fertilizers nutrient uptake proximate composition sulfate de cuivre sulfate de zinc sulfate ferreux sulfato de cinc sulfato de cobre sulfato ferroso technique analytique zea mays zinc sulphate