| Abstract: | Root studies and phosphorus uptake of rye-grass and red clover under field conditions Root parameters (fresh weight, density, surface, length, cation exchange capacity) and phosphate uptake were studied with rye grass and red clover, grown in the field on a brown podsolic soil. In all root parameters, ry grass was superior to red clover. Also, phosphate uptake of rye grass was higher than that of red clover. The greatest difference between both species was found in root length, that of rye grass being about five times longer than that of red clover. Rye grass had longer root hairs than red clover; whereas root diameter of clover was about twice as thick the average rye grass. Significant correlations were observed between root parameters and phosphate uptake in the plants studied. The highest correlation coefficients were obtained for the relationship P-uptake versus root length (clover 0.91***, grass 0.87***) and P-uptake versus root fresh weight (clover 0.92***, grass 0.88***). The phosphate uptake per unit root parameters was significantly higher in red clover, compared with rye grass, for the parameters root fresh weight, cation exchange capacity and root length. Because of this high P-uptake rate for clover it is assumed that clover also requires a higher P-concentration in soil solution as compared with grass. Thus grass may still grow with low P concentrations in the soil solution without P deficiency at which clover cannot grow. It is for this reason that in mixed swards clover is depressed by grass, if the available P in the soil is low. |
