Advanced Strategies to Reduce the Nitrate Content in Vegetables

Nitrate is a naturally occurring form of nitrogen and is an integral part of the nitrogen cycle in the environment. Besides, it may originate from fertilizers, decaying plants, manure and other organic residues. However, due to the increased use of synthetic nitrogen fertilizers and livestock manure in intensive agriculture, vegetables and drinking water may contain high concentrations of nitrate, acting as an anti-nutritional compound that is harmful for human health and provoking, through its reduction to nitrite, methemoglobinemia and increased cancer risk. Recently, the harmfulness of nitrate has been disputed, and some studies have proposed that the nitrate may be considered as a compound necessary for health, and not a harmful substance. Nevertheless, the European Commission has set maximum levels for nitrates in foodstuff [namely, spinach, lettuce, rocket and processed cereal-based foods and baby foods for infants and young children - Regulation (EC) N. 1258/2011] and, by law, those limits cannot be exceeded.

The nitrate accumulation in the vegetables is influenced by many factors: the species, the consumed organ, the nitrogen fertilization and the light intensity. The purpose of this Research Topic is therefore highlighting the current advances regarding the reduction of nitrate content in vegetables by the means of the most recent physiological findings, cultural practices and technological innovation. All types of manuscripts (Original Research, Reviews, Perspective, General Commentary, etc) are welcome.

We aim to showcase plant nutrition aspects and techniques to reduce the nitrate concentration in leafy vegetables, such as supplementary lightning and its effect on nitrate reduction in vegetables, soil-less systems as a technique to produce vegetables with reduced nitrate, and use of biostimulants.