A New Fertilization Approach for Bread Wheat in the Mediterranean Environment: Effects on Yield and Grain Protein Content

Plant biostimulants represent an innovative and sustainable solution to address the challenges of the future agriculture, especially when they are used to improve yield and quality of staple crops. The objective of this research was to study, over three consecutive seasons, the effect of a novel fertilization plan (Thesis 2, T2) on the productivity and protein content of bread wheat (<i>Triticum aestivum</i> L.), as compared to the traditional fertilization pattern (Thesis 1, T1), commonly used in Tunisia. T2 was based on the use of a pre-sowing soil bioenhancer (SBE, commercially known as ‘Terios’) and a topdressing with foliar bio-stimulant (FBS, commercially known as ‘Celerios’), obtained by nanotechnology transformation of Y-CaCO₃ minerals (called ‘vaterite’); while T1 was based on the use of diammonium phosphate (DAP) at pre-sowing and ammonium nitrate (AN) during the growing season. FBS was applied two times each season and at one rate (3 kg ha⁻¹). In each farm and experimental year, the following traits were recorded: plant height (cm), whole aerial biomass (t DM ha⁻¹), grain yield (t ha⁻¹, 13% moisture content), harvest index, grain weight (mg), spike density (number of spikes per m²), grain protein content (%). T2 protocol slightly, but significantly, increased yield, yield components and grain protein content, while it decreased plant height at harvest. These results suggest that the use of FBS could be of great interest for the cultivation of bread wheat under Mediterranean climatic conditions, as it can make plant nutrients rapidly available even when the uptake from the soil is hindered by water scarcity.