Impact of varieties, plant available Si and nutrients in straw Si and grain yield at the Mauguio experimental station (Southern France)

The concentration of silicon in crops depends on soil composition and plant type but whether grain yield depends on the wheat varieties that are enriched in Si in wheat remains poorly documented.

Field and pot experiments were performed on calcareous Cambisols near Montpellier, France, with eight wheat varieties commonly grown in the region. Additionally, we examined two agricultural modalities: with NPK fertilization (CON) and without (CTR). Our investigations included an analysis of soil physicochemical parameters and bioavailable silicon (PAS) extracted by CaCl₂.

There was a significant positive correlation between grain yield and silicon concentration in straw. Interestingly, none of the other soil parameters demonstrated a correlation with grain yield. Although the CON plots exhibited higher levels of clay, CaCO₃, organic carbon, and nitrogen than the CTR plots, these differences did not impact the PAS, straw silicon, or grain yield. Furthermore, a pot experiment involving the Anvergur variety corroborated that the straw silicon concentration remained unaffected by the soil characteristics observed in the field.

Our findings indicate that foliar Si concentrations in wheat does not depend on soil Si pools and NPK addition and that wheat varieties enriched in silicon have the highest grain yield. As such, selecting wheat varieties with high silicon content is pivotal for sustaining optimal yields.