Fertilization of rubber accounts for a considerable portion of recurrent expenditure. This study attempts to compare the cost of two alternative recommended methods of fertilizer application for mature rubber viz. the readily available conventional premixed fertilizers against the site specific soil and foliar survey based fertilization. The sample consisted of 669 mature rubber fields selected from 12 estates in the Kegalle district. The results clearly suggest that soil and foliar survey based method of fertilizer application is economical than the use of conventional pre-mixed fertilizers inspite of the additional sampling and analytical costs involved in the former method. The estimated difference in cost between the two fertilizer schemes is nearly Rs. 1150 ha/year during the initial 13 years of tapping. The behaviour of cost curves under the soil and foliar approach varied by clone type. The high yielding clone of RRIC 100 consumed more nutrients compared to the low yielding clone of PB 86. The study also suggests some insight into policy implications.