The effect of sulfur and Thiobacillus inoculant on soil pH, dry matter weight and phosphorus absorption by Canola

Supplying phosphorus demand for plants is possible from two ways: chemical and biological fertilizers. A main amount of phosphorus in chemical fertilizers become unsoluble in soil and out of reach for plants. some sulphur oxidizing microorganisms reduce soil pH and transform phosphorus from unsoluble to soluble form. In order to consider the effect of sulphur and Thiobacillus inoculant on soil pH decrease and increase in ability of phosphorus absorption, a greenhouse experience was carried out in factorial form and Randomized Complete Block Design (RCBD) containg 5 levels of elemental sulphur (200, 400, 600, 800 and 1000 kg/ha) and 3 level of inoculant (without, 5 & 10 gram in pot with 107 bacteria per gram) with 3 replications in 1388-89. The results of variance analysis indicated that the effect of all ingredient on absorption of phosphorus and decrease of pH was significant in 1%. Mean of phosphorus in treatments without inoculant was 21 ppm, however in treatments with inoculant was 28 ppm and resulted to 33.33% increasing and sulphur and bacteria interaction resulted to 165% increase in ability of phpsphorus absorption and soil pH decreased 1.05 unit. Increase in absorption of phosphorus by plant was significant, also increased dry matter of plant but it was not significant and it was because of experience error.