Belén Martínez-Alcántara
Ana Quiñones
Eduardo Primo-Millo
Francisco Legaz
Instituto Valenciano de Investigaciones Agrarias, Spain
Efficient use of fertilizer N has become a first-order concern in modern citrus production due to nitrate contamination of ground and surface waters. Excessive N fertilizer rates typically increase N leaching and may also result in ground water contamination (Alva & Paramasivam, 1998; McNeal et al., 1994).
It has been estimated that 50-70% of the nitrogen provided to the soil is lost (Hodge et al., 2000), which contributes to 50-80% of the total N delivered to groundwater in most countries of the European Union (EEA, 2003). Interest in improving utilization of fertilizer N by citrus has been particularly widespread in Mediterranean areas, were citrus cultivation predominates, and most wells show nitrate concentrations clearly above the limit of the World Health Organization (WHO, 2004).