Monitoring plant nutritional status: bioindication and biomonitoring

The negative economic and environmental impacts due to excessive use of mineral fertilizers, together with instability of their cost that are globally growing, make clear the need to select crops with high yield at low fertilizers input (FAO, 2015). This is a primary goal considering that the needs of food for the expected world population of about 9 billion in 2050 will require a marked increase in yield per soil surface unit (Godfray et al. 2010). Moreover, a restrain in the use of fertilizers is fundamental for the poorer areas of the planet where a limited availability of economic resources for their purchase is often combined with a low fertility of the soils (Sanchez, 2002