Agricultural systems are constantly under environmental pressure, and the continuous rise of the global population requires an increasingly intensification of agronomical productivity. To meet the current global food demand, particularly in depleted ecosystems under adverse climate conditions, the development of novel agronomical practices, which ensure crop productivity while safeguarding minimal impact to the environment, must be encouraged. Since aluminium (Al), cobalt (Co), selenium (Se), silicon (Si) and sodium (Na) are not essential to plant metabolism, their benefits are often neglected or underestimated in agriculture; however, several studies support their advantages in sustainable agriculture when properly employed. The agronomical uses of these elements have been studied in the last decades, delivering important cues for the improvement of food and feed production worldwide due to beneficial effects in plant growth and productivity, nutrient balance, pest and pathogen resistance, water stress management, heavy-metal toxicity alleviation, and postharvest performance. However, their application has not been addressed as part of a holistic conservation strategy that supports the sustainability of agroecosystems. Here, we discuss the potential use of these elements in sustainable agriculture, and the knowledge gaps that hinder their effective integration into agronomical practices, which result in equally profitable applications while supporting environmental sustainability.

The use of chemical fertilizers has led to significant environmental pollution. An alternative to these fertilizers is the use of natural compounds, such as phytohormones, which promote germination and crop development. However, environmental factors can affect natural compounds, reducing their effectiveness. Therefore, increasing their stability without decreasing their activity to improve crop quality is essential. This study produced and characterized chitosan and sodium tripolyphosphate (TPP) nano-microparticles (NMP) loaded with Bacillus subtilis extract and evaluated their impact on tomato seed germination. We employed two experimental designs (Box–Behnken and Box–Hunter–Hunter) to determine the optimal production conditions and characterized the NMP using DLS, SEM, and FTIR. The optimal treatment consisted of 8 min of homogenization, followed by 8 min of ultrasound at a 70% amplitude, resulting in a particle size of 330.7 nm, a polydispersity index of 0.25, a zeta potential of 34.3 mV, and an encapsulation efficiency of 68.8%. The NMP loaded with bacterial extract was applied to tomato seeds as a 50% dilution pretreatment. NMP achieved the best results, with a 72% germination rate (1.6 seeds per day) and an average germination time of 3.8 days. It is concluded that the experimental designs helped improve particle properties and that the chitosan and TPP coating enhances the stability and activity of the bacterial extract, potentially benefiting agronomic applications.

Background and aims: Legume residues are important organic inputs, but their effects depend on residue chemistry and application rate. This study examined how pea ( Pisum sativum ) and field bean ( Vicia faba ) residues with contrasting phytochemical compositions influenced soil functioning and subsequent barley growth, assessing how residue quality and dose shape soil responses. Methods: A sandy loam soil was amended with residues from four legume genotypes with contrasting phytochemical profiles but similar C:N ratios, applied at low (5 t ha⁻ ¹ ) and high (20 t ha⁻ ¹ ) rates. Unamended and mineral fertilization treatments were included for comparison. Barley was then grown in a microcosm setup for 8 weeks, and soil CO₂ efflux, microbial biomass C, inorganic N dynamics, and plant biomass were assessed. Results: High-dose applications substantially increased cumulative CO₂ emissions but led to reduced microbial biomass, lower nitrate availability, and significantly suppressed barley growth, particularly for high-phenolic genotypes. In contrast, low-dose low-phenolic residues increased microbial biomass, promoted nitrification, and supported barley growth comparable with mineral fertilizers. Phenolic-rich residues maintained higher ammonium levels and showed reduced microbial and plant responses, indicating inhibitory effects of certain phytochemicals on soil processes. Conclusion: Residue impacts on soil processes and crop performance depend strongly on both phytochemical composition and application rate. Low-phenolic residues applied at moderate doses have positively impacted microbial functioning, nitrogen cycling, and barley biomass, whereas high doses, especially of high-phenolic material, were detrimental to microbial activity and plant growth. Integrating residue chemistry into nutrient management could enhance the sustainability of legume-based cropping systems.