Register      Login
Crop and Pasture Science Crop and Pasture Science Society
Plant sciences, sustainable farming systems and food quality
RESEARCH ARTICLE

Effects of subsoil acidity and phosphorus placement on growth, root development and phosphorus uptake by Stylosanthes humilis and Desmodium intortum

A Pinkerton and JR Simpson

Australian Journal of Agricultural Research 34(2) 109 - 118
Published: 1983

Abstract

The effects of differing levels of soil acidity and phosphorus (P) deficiency on root growth and P absorption by Stylosanthes hurnilis and Desmodiurn intorturn were studied in columns of an acutely P-deficient soil. Four rates of P were supplied in layers located 15-45 cm (dilute) or 20-25 cm (concentrated) below the soil surface. Calcium carbonate was added to some columns to raise the pH of the subsoil from 5.4 to 5.9 (in water). Yield and P uptake by D. intorturn without lime was always lower than yield and uptake by S. humilis, and there was little response to lime by either species at low P rates. At the highest P rate, however, there was a large interaction between lime and P placement for D. intortum. S. humilis produced finer roots and had a greater root density than D. intorturn in the fertilized layer; it also responded in root fineness to concentrated P and to lime. D. intortum did not respond in root fineness, but the highest rate of concentrated P with lime stimulated P absorption and transport as well as shoot growth. Efficiency of P uptake (i.e. per unit length of root) did not account for the differences between species. The success of S. hurnilis was due to its ability to exploit acidic soil layers under conditions of low P supply by forming dense masses of fine roots, rather than to an innate highly efficient P uptake.

https://doi.org/10.1071/AR9830109

© CSIRO 1983

Committee on Publication Ethics


Export Citation Get Permission

View Dimensions