Abstract

Rasool Khatibi

The present research was conducted in the Research Field of Agricultural Research Center of Chahnimeh, Zabol, Iran. Data related to the combined effects of rock phosphate, P solubilizing bacteria, sulfur and sulfur oxidizing bacteria on Raphanus sativus growth is scanty. The experimental design was a completely randomized design with eight treatments in three replicates. Treatments including: (1) control, (2) triple super phosphate (80 kg/ha), (3) rock phosphate (160 kg/ha), (4) rock phosphate + organic matter (tea waste, 1000 kg/ha), (5) rock phosphate + organic matter + P solubilizing bacteria, (6) rock phosphate + elemental sulfur (1000 kg/ha) + Thiobacillus sp., (7) rock phosphate + Thiobacillus sp. + organic matter, (8) rock phosphate + elemental sulfur + Thiobacillus sp.+ organic matter were tested in plots measuring 3 x 7 m. At harvest crop yield and the related components were determined. Treatment 2 resulted in the highest amount of yield and stover with a 60 and 92% increase, relative to the control treatment, respectively. The next highest corresponding values were related to treatment 8 at 38 and 70%, respectively, not significantly different from treatment 2. Treatment 8 produced the highest oil percentage, followed by treatment 2 (39% increase) relative to the control. Sulfur treatments resulted in the highest oil percentage. The combination of chemical and biological methods (biofertilizers) can be a favorable method to increase the efficiency of naturally (rock phosphate) and synthetically (elemental sulfur) produced resources and hence optimization of chemical fertilization for crop production.