QUẢN LÝ DINH DƯỠNG CHO NGÔ THEO VÙNG CHUYÊN BIỆT TẠI MIỀN BẮC VIỆT NAM

Maize is the second major cereal crop in Vietnam after rice. Domestic production dramatically increased during the past 20 years. The currently recorded average maize yields in comparison to climatic-genetic yield potential indicate that there is a large scope for further increasing the maize production by closing this yield gap. The maize production systems in Vietnam vary depending on agro-ecological and socio-economic conditions and using one fertilizer rate affects soil fertility, agronomic and economic. The principle objectives of subject are the identification of major production constraints in the main maize growing areas and the development of tools to overcome them in a site specific approach. Results of Site-Specific Nutrient Management for Maize in North Vietnam increased maize yield, highest in Son la (yield responses 2.83 tons ha-1 ), Red river delta (2.22 tons ha-1 ) and Bac Giang degraded soil (0.52 ton ha-1 ). Increased profit from 24.5 - 56% compares to farmer practices. Decreased N 26%, increasing P and K appropriately 15, 18% in Son la, decreased N 18%, K 35%, and needs to increasing P 20% Red river delta, decreased N 20%, and increasing P and K appropriately 48, 36% in Bac Giang degraded soil.