Micro-organisms solubilizing insoluble phosphate mineral compounds in the rhizosphere of the rape plant (Brassica campestris)
Amor Asunción, M.J.; Frontera, G.M.; Janeiro, A.R.
Revista Argentina de Microbiologia 17(2): 97-101
1985
ISSN/ISBN: 0325-7541 PMID: 3870745 Document Number: 264981
The aim of this study carried out in a soil of the experimental station of the Faculty of Agronomy of the University of Bs. As. was to study the influence of the root of Brassica campestris on the functional group of microorganism dissolving insoluble phosphorus mineral compounds, bi and tricalcium phosphate. The microbiological quantitative analysis showed the following values: for bicalcium-phosphate: 5.7 X 10(8), 2.8 X 10(8), and 1.0 X 10(8) and for tricalcium phosphate: 3.2 X 10(8), 1.7 X 10(8), 2.1 X 10(7) of dissolving microorganisms of such compounds per g/soil for the rhizoplane, Ro, and the two regions of the rhizosphere, R1, and R2, respectively, in both cases against 6.4 X 10(2) and 2.0 X 10(2) for bicalcium phosphate and tricalcium phosphate, in the testing soil, respectively. In artificial culture media, the dissolving capability of developed microorganisms was determined: for bicalcium phosphate: 2.32; 17.53; 12.11; and 17.79 and for tricalcium phosphate; 0.88; 13.56; 7.98 and 2.88 percentage of dissolution, in both cases, for the testing soil, Ro, R1 and R2 respectively. These results show the development in the rhizosphere of Brassica campestris of a very active microbiological process of insoluble phosphorus mineral compounds dissolution; thus, the growing of Brassica may be expected to raise the phosphorous fertility level of the soil.