MOVEMENT OF PHOSPHORUS TO BARLEY ROOTS GROWING IN SOIL

Abstract

A plant growth room experiment was conducted using seven soils of Alberta with a treatment of 300 ppm of P on four of the soils. The contributions to the movement of P to the roots were calculated according to the method of Barber and co-workers, with some modifications. Results of the experiment showed clearly that movement by mass flow was the most important process of P transport to roots in soils treated with 300 ppm of P. Apparent diffusion was found to be the major process of P movement to roots in untreated soils, which included two soils with naturally high levels of available P. Root interception was found to be of least importance in P movement to roots. Since the concentration of P in soil solution affected the amounts of P reaching the roots by diffusion, mass flow or root interception, the importance of the determination of soil solution P is emphasized. A correlation of 0.86 was obtained between the yield and soil solution P concentration of the untreated soils.