Because of the low percentage of the P-fertilizers available to plants the year of application, high rates of soluble Pfertilizers
are used. With field cultivated forage and grain maize, it is possible to reduce the rate of soluble P-fertilizer added
by 50% without reducing yield, if plants are inoculated with appropriate PSMs [10, 34]. This suggests that it might be
advantageous to add PSMs directly to soluble P-fertilizers to increase the availability of P the year of application.