THE RATE-LIMITING STEP IN PLANT NUTRIENT ABSORPTION FROM SOIL

Abstract

The rate of uptake of a nutrient may be limited by its rate of diffusion through the soil or by the ability of the root to absorb it from low concentration in the soil solution. In the growth-response range of concentration, uptake of N, P, and K appears to be limited by diffusion. Transpiration rate, in these conditions, should have little influence. The root may be able to increase the soil solution concentration of sparingly soluble nutrients. The rate of uptake of a nutrient may be limited by its rate of diffusion through the soil or by the ability of the root to absorb it from low concentration in the soil solution. In the growth-response range of concentration, uptake of N, P, and K appears to be limited by diffusion. Transpiration rate, in these conditions, should have little influence. The root may be able to increase the soil solution concentration of sparingly soluble nutrients. © Williams & Wilkins 1977. All Rights Reserved.