Effect of water soluble and water inso luble types of phosphate fertilizer on the growth of coffee seedlings.

Abstract

A greenhouse study was carried out to evaluate the effects of different sources of phosphorus applied at different rates on coffee (Coffee canephora) seedlings at the headquarters of Cocoa Research Institute of Nigeria, Ibadan in 1999 and 2000. This is towards finding a lasting solution to the problem of P-limitation in soil and supply by the coffee growing farmers.
Two sources of phosphorus fertilizers: Single super-phosphate (SSP)(water soluble) and Sokoto rock phosphate (SRP) (water insoluble) were applied at rates equivalent to 20 and 40 kg P205 ha-1.
Coffee seedlings with SSP applied at 40 kg P205ha-1 was significantly higher (p< 0.05) in height, leaf area and dry matter yield compared to other application rates. The relative agronomic efficiency of SRP applied at 20kg P205ha-1 was significantly higher (p<0.05) compared to SRP applied at 40 kg P205 ha-1. Effect of SRP in all the rates tested was lower compared to that of SSP at corresponding rates.
Keywords: Sokoto rockphosphate (SRP); Single super phosphate (SSP); Coffee; Relative agronomic efficiency (RAE).