A Narrative Review of the Facts and Perspectives on Agricultural Fertilization in Europe, with a Focus on Italy

Fertilizers stand at the base of current agricultural practices, providing the nutrient sustainment required for growing plants. Most fertilizers are synthetic chemicals, whose exploitation at very high levels poses a risk to cultivated land and the whole environment. They have several drawbacks including soil degradation, water pollution, and human food safety. Currently, the urgent need to counterbalance these negative environmental impacts has opened the way for the use of natural and renewable products that may help to restore soil structure, microorganism communities, nutrient elements, and, in some cases, to positively enhance carbon soil sequestration. Here, we endeavor to reinforce the vision that effective strategies designed to mitigate negative anthropic and climate change impacts should combine, in appropriate proportions, solutions addressed to a lower and less energy intensive production of chemicals and to a more inclusive exploitation of renewable natural products as biological soil amendments. After drawing an overview of the agricultural energy demand and consumption of fertilizers in Europe in the last few years (with a particular focus on Italy), this narrative review will deal with the current and prospective use of compost, biochar, and neem cake, which are suitable natural products with well-known potential and still-to-be-discovered features, to benefit sustainable agriculture and be adopted as circular economic solutions