Nitrogen Fertilization II: Fertilizer Requirements

Abstract

The N balance allows the calculation of the fertilizer requirement which depends on the amount of N absorbed by the crop, the amount of inorganic N in the soil or produced by mineralization and N losses of the system, which are quantified by the Recovery Efficiency. A fertilization plan should take into account the variability of environmental factors, especially rain, to distribute the N with flexibility to match the specific conditions of each year. Doing so we will avoid yield reductions due to N deficiency and the negative environmental impacts by excess application. Fertilization of trees should be based on the nutrient balance (mature trees) or the growth rate expected from actual transpiration.