Site-Specific Nutrient Management for NPK Fertilization in Sugarcane in Mekong Delta Alluvial Island Soil
Site-specific nutrient management (SSNM) was used to: (i) evaluate the effect of inorganic and sugarcane dregs as fertilizers on sugarcane yield and Brix and (ii) determine the NPK uptake and agronomic efficiency (AE) thereby to recommend fertilizers rate for sugarcane cultivation in the alluvial island soil. Field experiment with sugarcane of new planting crop (2011) and ratoon crop (2012) was conducted at Cu Lao Dung District of Soc Trang. The experiment was arranged in a Randomized Complete Block Design (RCBD) with four replication and two factors: (A) lacking particular macronutrient(s) (NPK, NP, NK, PK) and (B) sugarcane dregs (BBM, KBB). Results showed that potassium application at 200 kgK2O/ha increased Brix of sugarcane. Nutrients supplied by the soil were 32.6; 46.2 and 56.1 (N, P and K respectively) as percentage of total nutrient requirement of the plant. Nitrogen was the most important factor affecting sugarcane yield. Sugarcane dregs application at 10 tons/ha increased NPK uptake by the plant. By using SSNM,331 N-155 P2O5-253 K2O (kg/ha) are recommended for sugarcane grown in the alluvial island soil.