Monitoring plant nutritional status

Methods and techniques effective in achieving yield objectives, optimizing the use of resources and preventing environmental contamination are defined as agronomic Best Management Practices (BMPs). Considering fertilisations BMPs pursue the aims to match mineral nutrient supply with crop requirements, minimizing their losses from the field. If spatial and temporal information about crop needs were available, precision fertilisation approaches could be planned in order to increase fertiliser use efficiency and to improve some economic and environmental aspects related to the crop systems. The state of the art and the research perspectives on the fine tuning of optical devices allowing proximal or remote sensing at sub-field scale of crops traits related to plant nutritional status, as well as on the exploitation of the gene fusion concept in developing transgenic bioindicators monitoring the nutritional status of the plants are here reviewed and discussed. Concerning the latter aspect particular attention is paid to the development of synthetic promoters conferring to the biondicator nutrient specificity and also able to target the expression of the associated reporter genes in organs in which their signals should be early and easily detectable.