European areas which are close to Mediterranean Sea may be divided into two main agricultural zones, sharing in common the climatic environment, though differentiated by economic factors, i.e. by the influence of specialized and market-oriented agriculture which is specially practiced in Western countries. In both agricultural zones, however, supply by chemical fertilizers and organic wastes like manure is rather limited if compared to Central and also Northern Europe.
Despite the low supply of nutrients to the soil, in Southern Europe the application of modern technologies may cause the increase of agricultural productions to levels which were unbelievable previously. If we examine a case of farming on a large scale with crops extensively cultivated, like e.g. maize in Italy during the last few decades, we realize that much higher yields are obtained at present on much lower extensions of land. At least in Mediterranean countries, as aforesaid, higher yields are obtained by the use of comparatively low fertilizer rates, though increased soil tillage practices are made necessary, with parallel decrease of soil organic matter content and deterioration of soil structure. Since present differences are determined by historical reasons, and the adoption of modern agricultural technologies is rapidly growing in all the geographical environments, such soil critical conditions, due to the unsatisfactorily low organic matter content and the poor physical structure, may be expected to extend progressively to the entire Southern Europe including Eastern countries.
Evolution of fertilization criteria must rely on the principle of giving back to soil the nutrients lost with the harvests, and to adopt recycling criteria as far as possible. In other words, fertilizations must obey also to environmental rather than simply to agronomic principles. Many wrong environmental problems are put at present (some examples will be given), though the main natural problem remains the actual break of nutrient cycles at the soil level.
In addition to integrated nutrient management criteria, modern fertilizers may be sought which tend to facilitate an active role of plant roots in nutrient absorption from soil. Also, development of new generations of biostimulants, even based on suppressiveness properties, may be envisaged in next decades, in order to favour overcoming of difficulties, which hinder or interfere with development of an ideal plant growth.
