The Effect of Inoculants of Thiobacillus and Aspergillus on Corn Growth

Abstract Phosphorus (P) is one of the essential macronutrients for growth and development of plant. Phosphorus is added to soil in the form of phosphatic fertilizers, part of which is utilized by plants and the remainder converted into insoluble fixed forms. Increasingly high cost of chemical fertilizers has been the major stimulus to search for an alternative, naturally-occurring, phosphate source. The researchers offered phosphorus rocks as a valuable alternative source for P. fertilizer. Unfortunately, rock phosphate is not plant available in soils with a pH greater than 6. One method to increase soluble form inorganic P is application of phosphate solublizing microorganisms and sulfur oxidizing bacteria (Thiobacillus) with rock phosphate. A greenhouse experiment was carried out with two bio fertilizers (bio fertilizers santes in incubation condition) in a soil with low available P on corn growth. The bio fertilizers were: rock phosphate with 20% sulfur, 15% vermicompost, Thiobacillus bacteria and Aspergillus fungi (BFS20V15) at three rates: 440 kg/ha (BF1) , 880 kg/ha (BF2), 1320kg/ha (BF3), rock phosphate with 20% sulfur, 15% vermicompost, Thiobacillus bacteria (BFS20V15) at three rates: 440 kg/ha (B1) , 880 kg/ha (B2), 1320kg/ha (B3), triple super phosphate (TSP), and control without phosphorus. In the greenhouse experiment, shoot dry matter, p uptake in plant and available p in soil were determined. The results showed that maximum yield obtained from BF3 with the shoot dry weight 7.2 g per plant and with no significant difference in relation to the triple super phosphate (7.5g) at 5% level. Also highest rate p-uptake resulted from BF3. There was significant difference between treatment BF3 and TSP on p-uptake. Results indicated that it could be possible to substitute rock phosphate inoculated with sulfur-oxidizing bacteria and phosphorous-solublizing fungus for super phosphate. Keywords: Uptake-p, pH Rock phosphate, Solfur, Vermicompost