Natural Strategies for Increasing Yields: The Role of Plant Extracts and Micronutrients as Natural Resources in Sustainable Intensification

Natural resources play a fundamental role in ensuring global food security, while agricultural production itself strongly influences their demand, extraction, and availability. This article discusses natural strategies for increasing crop productivity within the framework of sustainable intensification, focusing on the integrated role of plant biostimulants and micronutrients. Both groups of substances are analyzed from a resource-oriented perspective, highlighting their potential to be derived from renewable sources, particularly agro-industrial by-products and plant biomass. Plant extracts obtained from fruit, vegetable, and cereal processing residues contain numerous bioactive compounds, including phenolics, amino acids, peptides, and organic acids, which can stimulate plant growth, improve nutrient uptake, and enhance tolerance to abiotic stress. Micronutrients such as Fe, Zn, Mn, Cu, and B are also strategic resources in crop production because they regulate key metabolic processes and influence the efficiency of macronutrient utilization. Their effectiveness, however, depends strongly on chemical form and bioavailability in soil–plant systems. The novelty of this work lies in integrating perspectives from plant physiology, coordination chemistry, and resource management to propose a conceptual framework in which plant-derived extracts and micronutrient complexes act as complementary tools supporting circular and resource-efficient agricultural systems.