Optimizing the Nitrogen Use Efficiency in Vegetable Crops

Nitrogen (N) is the most limiting nutrient for the production of vegetable crops, but anthropogenic sources pose risks due to its transformation into several reactive forms and movement throughout the environment. To mitigate the impact of environmental losses, current research efforts aim to improve management practices to obtain a greater Nutrient Use Efficiency (NUE). From a chemical, biological, and ecophysiological perspective, at a reductionist level we have acquired a considerable mechanistic understanding about the N cycle, the varied N chemical forms, microbial interactions and physiology of crop uptake. However, at a holistic level, we are far from obtaining an adequate understanding of the myriad of multi-level cropping system, genetic, socioeconomic, environmental, and ecological interactions that have an effect on the N cycle and NUE. Here, based on a selected review of the literature, we provide a perspective on the potentials to increase the NUE of vegetable crops, by adopting a range of best management practices and by highlighting some of the N x system interactions that may be considered to better understand the complex dynamics of the N cycle, to optimize the NUE of vegetable crops, and to explore alternatives to the reliance on the use of synthetic N sources.