Nitrogen use efficiency in rainfed Mediterranean agriculture

Abstract

Mediterranean regions are the ones with a typical rainfall pattern, characterized by rainfall in winter and dry, hot summers, being winter rainfall much larger than summer’s. Strong water deficits occurs for several months. Thus, nitrogen use efficiency (NUE) and its improvement is linked to improvements in water availability and water use efficiency. NUE is lower than in temperate areas and large opportunities exist to improve it. Rainfed cereal crops are major nitrogen consumers in these area and increases in NUE may be achieved through the proper design of the agricultural system. Proper timing of fertilizer operations, appropriate choice of N fertilizer type and implementation of analytical tools adapted to the specific conditions are key issues, in addition to others, like conservation tillage or crop breeding. Some attention is paid to organic fertilization and more intensive rotations, avoiding bare fallow as a way to increase soil quality and overall NUE. To face these challenges, as the management complexity of the agricultural system increases, a good standard education is needed for land managers.