Impact of rock materials and biofertilizations on P and K availability for maize (Zea Maize) under calcareous soil conditions.

The present work evaluated the synergistic effects of soil fertilization with rock P and K materials and co-inoculation with P and K-dissolving bacteria [PDB (Bacillus megaterium var. phosphaticum) and KDB (Bacillus mucilaginosus and B. subtilis)] on the improvement of P and K uptake, P and K availability and growth of maize plant grown under limited P and K soil conditions (calcareous soil). The experiment was establishment with eight treatments: without rock P and K materials or bacteria inoculation (control), rock P (RP), rock K (RK), RP + PDB, RK + KDB and R(P + K)+(P + K)DB. Under the same conditions of this study, co-inoculation of PDB and KDB in conjunction with direct application of rock P and K materials (R(P + K)) into the soil increased P and K availability and uptake, and the plant growth (shoot and root growth) of maize plants grown on P and K limited soils.