Abstract
Apatite in Sri Lanka is mined from Eppawala (Eppawala Rock Phosphate or ERP). The finely ground product is used as a direct application fertilizer for tea, rubber and coconut. ERP is an indiscriminate mixture of more soluble primary crystals and a less soluble secondary phosphate matrix rich in ferruginous and aluminous compounds with an average P2O5 content of 30%. The primary crystals can easily be separated from the groundmass by mechanical separation to produce selectively mined primary crystals (SERP) which has higher P2O5 (35 to 42%) and lower R2O3 contents (around 1%) than the matrix. The ground SERP shows promise, as measured using yield and bicarbonate-extractable soil P, as fertilizer for rice grown in lowland and midland acid soils. In the second crop residues of SERP produced larger yields and bicarbonate-extractable P than Triple super phosphate (TSP) for the first crop. TSP is imported and its price is four times that of SERP. Therefore SERP is a potentially more profitable alternative fertilizer for TSP for rice on Sri Lankan acid soils.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
