Different Areas of the Root Absorb Different Minerals

 Different Areas of the Root Absorb Different Minerals

When diffusion is too slow to maintain high nutrient concentrations near the root, a nutrient depletion zone forms adjacent to the root surface. This zone extends from about 0.2 to 2 mm from the root surface depending on the mobility of the nutrient in the soil. Without growth, roots would rapidly deplete the soil adjacent to their surface Optimal nutrient acquisition therefore depends both on the capacity for nutrient uptake and on the ability of the system to grow into fresh soil.

(a) Root absorption of calcium in barley appears to be restricted to the apical region.

(b) Iron may be taken up either at the apical region, as in barley or over the entire root surface, as in corn. Potassium, nitrate, ammonium and phosphate can be

(C)absorbed freely at all locations of the root surface but in corn the elongation zone has the maximum rates of potassium accumulation and nitrate absorption

(d) In corn and rice, the root apex absorbs ammonium more rapidly than the elongation zone does.

(e) In several species, root hairs are the most active in phosphate absorption.