Water and nitrogen fertilization management in light of climate change: impacts on food security and product quality

Water and nitrogen (N) are key elements determining crop yield. In recent decades, the increasing world population and climate change have led to serious impacts on these resources often putting at risk food security, food safety, and product quality. In this chapter, we analyze, in light of climate change, the impact of decreased water availability and quality and the influence of N fertilization on crop yield and product quality of several relevant agronomic crops. Finally, we present an overview on the current and novel strategies to enhance water and N use efficiency (WUE and NUE). Water scarcity and low N fertilization negatively affect yield and product quality, resulting in dramatic economic losses for the agricultural sector. However, an excessive N crop supply also leads to similar effects and has a detrimental environmental impact, reinforcing the need for precise strategies that allow an optimal water and N management adjusted to the specific crop requirements (species, cultivars, and stage of development), and also the need to establish target breeding programs for enhanced WUE and NUE. Despite a high number of scientific and academic publications in this field, in this review it is highlighted a generalized lack of knowledge on combined plant stresses, but these are particullarly important in light of climate change scenarios since there is often a strong crosstalk among them.