Characterization of Some Agricultural Soils: Presence and Activity of Tilemsi Rock Phosphate-Solubilizing Thiobacilli

Bioresource Efficacy of Phosphate Rock, Sulfur, and Thiobacillus Inoculum in Improving Soil Phosphorus Availability

“…Appears due to Thiobacillus bacteria inability to produce spores along with some soil unfavorable factors including high pH, high base status and apparent lack of available energy substrates especially in soil which had not been previously fertilized with sulfur, cause that these bacteria populations is low in most of agricultural soil. The results of the present study were in conformity with those recently recorded M a n u s c r i p t 8 by other researchers that the population of Thiobacillus bacteria in most agricultural soils is low (Babana et al 2011). …”

“…This result of experiment coincide with the findings of Bhatti and Yawar (2010) who observed that A. Ferrooxidans, A. Thiooxidans and also the mixed culture of these bacteria solubilized significant amounts of P from#phosphate rock in bioleaching process as compared with pure culture alone. Babana et al (2011) also showed that all the isolates of Thiobacillus can produce sulfuric acid by oxidizing elemental S and therefore, solubilize phosphate rock. Similar results were recorded by Costa et al (1992) andChi et al (2006) for P solubilization from phosphate rock containing pyrites with acidophilic sulfuriron-oxidizing bacteria.…”

“…This appears that they had similar ability to produce sulfuric acid and dissolve phosphorus compound. In this sense, Babana et al (2011) have reported also that the capacity of acid production by bacteria depends on the species of Thiobacillus.…”

“…Due to high cost of#soluble phosphorus fertilizers, the use of phosphate rock had been recognized as a valuable#low-cost alternative for the conventional water-soluble P fertilizers. However, due to their#low solubility in calcareous soils, direct#application of rock phosphates is not recommended.#Several strategies have been used to enhancing phosphorus availability from rock phosphates#such as partial acidulation of phosphate rock (Rajan and Watkinson, 1993), mixing#phosphate rock with composting organic wastes, using phosphate rock along with some microorganism such as P solubilizing bacteria, endomycorrhizae or ectomycorrhizae#and application of acidifying materials such as elemental sulfur along with sulfur oxidizing bacteria (Babana et al 2011). Among the biological means, using phosphate solubilizing bacteria and arbuscular mycorrhiza usually are not suitable for orchard trees.…”

“…Among them, the group of bacteria belonging to the genus Thiobacillus are the most important and common organisms in Soxidization (Tabatabai 1986;Wainwright 1984). The most agricultural land especially calcareous soils contain very few Thiobacillus (Babana et al 2011;Rupela and Tauro 1973;Swaby and Fedel 1973) and the population of Thiobacillus increases by application of sulfur in the soil (Germida and Janzen 1993). The soils with low numbers of Thiobacillus generally show rates of slowed sulfur oxidation; although when the soil inoculated with Thiobacillus bacteria, population of these organisms increase and followed by sulfur oxidation are accelerated (Germida and Janzen 1993).…”