PHOSPHATE SOLUBILIZING MICROORGANISMS UNDER NONSTERILE CONDITIONS

Two species Penicillium aurantiogriseum and Pseudomonas sp. (PI 18/89) highly able to solubilize inorganic phosphates were tested for their efficiency to dissolve calcium phosphates under non-sterile conditions . In laboratory experiments plant available phosphorus was only increa sed when phosphate solubilizing microorganisms disposed of sufficient nutrient supply. Field studies indicate that phosphate solubilizing mi croorganisms were too vulnerable and unreliable to be used in agricult ure. Too many biotic and abiotic factors influence outcomes of such ex periments in an - up to now - unknown way, making results hardly predi ctable.