Effect of Eppawela High Graded Rock Phosphate (HERP) Applied with Vinasse on Yield and Quality of Sugarcane (Variety CO775)

Abstract

The disposal of Vinasse, effluent from the ethanol industry is a main pollutant to the environment. HERP is a locally available cheap source of Phosphorous fertilizer, manufactured from Eppawela Rock Phosphate deposit in Sri Lanka, which is less soluble and has limited use in sugarcane cultivation. Therefore, an experiment was conducted to investigate the effect of different rates of HERP as the P source, and Vinasse on Sugarcane yield and quality. This was conducted at the fields of Sugarcane Research Institute (SRI), UdaWalawe, using variety CO775. Five levels of HERP (50, 75, 100, 125, 175 P₂O₅ kg/ha) with and without Vinasse were tested on the yield, juice quality, leaf P and available soil P of Plant crop and first Ratoon. Vinasse was applied at the rate recommended by SRI to furrows of both Plant and Ratoon crop. The study revealed that the cane yield and millable cane count in ratoon crop has significantly increased by applying Vinasse. Leaf P content of Plant and Ratoon crop has improved by the application of vinasse. Moreover, Vinasse has improved available soil P tested after plant crop harvest. In addition, cane juice quality parameters in both plant and ratoon crop were not affected by applying HERP as P source with or without Vinasse. Thus, there is a potential to use HERP with Vinasse as a cheap source of Phosphorous for sugarcane in Sri Lanka.