EFFECT OF Al CONCENTRATION IN CULTURE SOLUTION ON THE GROWTH AND N_2-FIXATION OF SOME TROPICAL PASTURE LEGUMES

概要

論文の詳細を見る
Four tropical pasture legumes and a temperate pasture legume were grown at graded levels of Al concentration in a culture solution in order to examine the effect of Al on their growth and N_2-fixing activities. In addition two tropical pasture legumes dependent upon combined-N or symbiotically fixed-N were exposed to graded levels of Al concentration and data on their weights, N_2-fixing activities, root length were collected. The results obtained were as follows. 1) The tolerance to Al in terms of the relative weight of the whole plant in the Al treatments to that of plants which did not receive Al was in the order of: Macroptilium atropurpureum≑Stylosanthes humilis≑Centrosema pubescens>Desmodium intortum>Trifolium repens. 2) The critical concentration of Al with respect to N_2-fixing activities was about 20 ppm in some tropical pasture legumes except for M. atropurpureum, in which Al concentration up to 100 ppm in the culture solution had no adverse effect on N_2-fixing activity. 3) In both M. atropurpureum and C. pubescens, the whole plant weight decreased more in the plants dependent upon symbiotically fixed-N than combined-N. 4) In M. atropurpureum, 20 ppm Al treatment decreased the total root length and increased the root thickness whereas in C. pubescens, above that level of Al, the total root length decreased and the root thickness increased to a smaller extent.
社団法人日本土壌肥料学会の論文