Abstract
Nitrogen (N) is quantitatively the most important nutrient for plants, as their supply has a profound influence on many aspects related to growth and development. The most abundant N forms in agricultural soils are nitrate (NO3-) and ammonium (NH4+), while urea [CO2 (NH)2] is the main form of N used in fertilization. Increasing the nitrogen use efficiency (NUE) is a key factor for sustain…