Phosphate Solubilization and Changes of Certain Attributes in Soils as Affected by Bio-organic Fertilizers

           





T





HE PRESENT work was planned to study the influence of bio- organic additives, i.e. compost “CM” and farmyard manure “FYM”, as organic fertilizers, Bacillus megaterium “Bm” and Bacillus polymyxa “Bp”, as biofertilizers, on phosphate solubilization and certain attributes in sandy and alluvial clayey soils, periodically along 120 day incubation, in pot experiments, under greenhouse conditions.
 
Results showed that, all added amendments increased phosphate solubilization in both soils with time of incubation.  Incorporation of CM or FYM plus each of the biofertilizers greatly augmented phosphate solubilization, as compared with the single additive of each of the bio-organics. The increases resulted by using CM or FYM each with Bm, reached 105 & 62% and 88 & 51% above the control treatment in the sandy and clay soils, respectively. Treatments included the Bp, either alone or collaborated, despite their positive action, they gave lower values than those of the Bm.
 
Addition of CM or FYM slightly decreased the pH values of both soils, at the first period and somewhat had recovered towards the end of experimental duration. However, all amendments revealed inconsistence among the applied treatments on soil reaction “pH value”, generally within the succeeding intervals of incubation time. Nevertheless, the organic fertilizers generally excelled the bio-fertilizers, as well as combinations of the bio-organic treatments were thus more efficient in such concern (modifying the soil pH). Introduction of CM or FYM, each with Bm increased the concentration of the total soluble salts “TSS” by 48 & 59% and 65 & 80% above the control, in the sandy and clayey soils, respectively. Combination between the CM or FYM with the Bm resulted in lower increases, i.e. 40 & 52% and 55 & 66%, evolution rate of CO2augmented progressive with incubation time, when the clay soil excelled the sandy one, as the extents were 114 & 92% and 76 & 65% for CM+Bm, CM+BP, FYM+Bm and FYM+BP, respectively. Generally, the single addition of each of the bio-organic fertilizer was lower effective than the combined treatments.