Effective Utilization of Eppawala Rock Phosphate using Natural Microbe Cultures (Jeevamrutham)

Abstract

Phosphorus, is one of the most demanding essential nutrients for crops that is usually supplied through fertilizers. Sri Lanka has a rock phosphate deposit at Eppawala, which can be utilized as a source of phosphorus fertilizer after increasing its watersoluble phosphate. Biological processes such as microbial activities are economically and environmentally more suitable than the chemical processes in increasing the water-soluble phosphate of Rock Phosphate. Jeevamrutham is a mixture of microorganisms which contains high microbial activities. This study investigates the suitability of Jeevamrutham to increase the phosphate solubility of High-Grade Eppawala Rock Phosphate (HERP) both at laboratory and field levels. Five different microbial inoculums (Jeevamrutham) were prepared using soils taken from undisturbed Eco systems (Sinharajaand Badagamuwa forests, Nonperial Pine, Girandurukotte Teak, and Diyathalawa Turpentine plantations), Cow dung, Sugar, Gliricidia and Natural water. In a laboratory experiment, HERP was treated within columns. Available Phosphorus content of each sample was determined within 2 months in 7 days intervals. In a field experiment Zeamays was planted in treated plots with three different ways such as five different Jeevamrutham + HERP, Five different Jeevamrutham, and HERP. The plants which were grown in untreated soil were considered as the controlled. Available P2O5%, pH, and Organic matter content of soil were determined within 3 months in 14 days intervals. The average biomass of each plot was determined after 3 months. The laboratory experiment revealed that the available P2O5% of all treated samples were significantly higher (P<0.05) than the controlled samples in every week. It was evident from the field experiment that the available P2O5% of soil and average biomass of crops were significantly higher (P<0.05) in Jeevamrutham + HERP treated plots than that of the other treatments. The highest biomass was resulted in the Nonperial pine forest’s soil based Jeevamrutham + HERP treated Crops. The organic matter content of all treatments was significantly lesser (P<0.05) than the controlled while pH was retained at 5.1- 7.2 range. Jeevamrutham has increased the water- soluble phosphate in HERP and Jeevamrutham treated HERP can be used as a phosphorus fertilizer for short term perennial crops in Sri Lanka.