EFFECT OF SITE SPECIFIC NUTRIENT MANAGEMENT ON GRAIN YIELD, NUTRIENT USE EFFICIENCY AND RICE PRODUCTION PROFIT IN THE MEKONG DELTA

Evaluation of Site Specific Nutrient Management (SSNM) with Farmer's Fertilizer Practice (FFP) and Extension's Fertilizer Practice (EFP) on rice yield and nutrient use efficiency were conducted on 30 farms at six villages of three provinces as Can Tho, An Giang and Tien Giang in 2004. It showed the remarkable difference in grain yield and nutrient use efficiency among three fertilizer application methods. Grain yield of SSNM was similar or higher than those of EFP and FFP about 0.17 t/ha. SSNM supported to increase nutrient use efficiency of N, P and K. AEN, REN, AEP, REP, AEK, REK of SSNM plot were higher than those of EFP and FFP. AEN of SSNM plot got from 12 to 17 kg grain/kg N, higher than that of FFP plot from 1.1 to 3.4 kg grain/kg N. AEP of SSNM got from 25 to 46 kg grain/kg P 2O5, higher than that of FFP plot from 2.6 to 7.7 kg grain /kg P 2O5. AEK attained from 2.4 to 13.4 kg grain/kg K 2O, higher than that of FFP plot from 2.4 to 5.1 kg grain /kg K2O. Especially, REN attained at high value. It got from 0.51 to 0.56. SSNM supported to remarkable decrease fertilizer doses. It reduced at average of 11 kg N/ha, 5.2 kg P 2O5/ha and 16 kg K 2O /ha. On economic efficiency, SSNM helped to reduce fertilizer cost from 3.6 to 16.6%. SSNM contributed to increase income and profit for rice growing farmers through the decrease of fertilizer cost and increase of profit and fertilizer cost ratio. Indeed, SSNM is a new and efficient fertilizer application method. It should be trained and widely spread to farmers in combination with the programs such as IPM, high quality rice seed production, "three reductions, three gains", and so on.