Two greenhouse pot experiments were done on biofertilizers P (B. megaterium ), experiment 1(Expt. 1) and biofertilizer K (B. circulans ), experiment 2 (Expt.2). Rock sources were rock phosphate for P (RP) and potassium feldspars for K (RK).The design was a randomized complete block, factorial, 3 replicates. Addition of biofertilizer (B1) and no addition of it (B0) were tested with the rock source (A1) or without it (A0) ,with 4 treatment combinations of : neither (B0A0), bio only (B1A0) , rock only(B0A1) and both combined (B1A1). RP (150 g P kg-1) and RK (152 g K kg-1) were used at rates (mg kg-1 soil) of 300 mg P , and 240 mg K during soil preparation. Inoculation was done through seeds as well as through soil Increases in yield of whole plant (shoots+roots) growth (47 days) were 14.0% (B1A0) , 28.7% (B0A1) and 31.1% ((B1A1) in Expt.1 and 45.9, 63.6 and 75.1% respectively for Expt. 2. Respective increases in uptake were 28.9, 42.3 and 71.2% for N , 113 , 131 and 162% for P , and 9.3 , 17.8 and 29.3% for K in Expt. 1; 12.7, 10.4 and 47.5 % for N , 42.6, 36.9 and 57.8 % for P and 35.5, 40.2 and 85.0% for K in Expt. 2. The highest nutrient uptake increases upon applying the biofertilizer + the rock source occurred in P for Expt. 1 and in K for Expt. 2 .Available nutrients after end of growth in Expt. 1 increased by 75.0 and 50.0 and 77.4% respectively for N ; 26.2% , 1.3 and 56.4 % for P , but no increase for K. In Expt. 2 ,no increase occurred to N , and the only increase in P (14.5%) was by the biofertilizer + the rock source ; increases for K were 4.6 , 42.4 and 48.1 % respectively. |
