No abstract

Purpose Silicon (Si) can reduce abiotic stresses in plants and increase crop yield in semiarid climates. We aimed to assess the effect of an amorphous silica-based fertilizer (ASF) applied to soil on the yield, mineral nutrition, and health of an onion crop grown in northeast Brazil. Methods The ASF was applied at the rates of 0, 75, 125, 175, and 225 kg ha− 1. Yield and quality of bulbs as well as leaf concentrations of Si and nutrients were evaluated. Stress amelioration was assessed through Normalized Difference Vegetation Index (NDVI). Results ASF increased the yield of onions and enhanced the concentration of Si, N, P, K, Ca, Mg, B, Mn, Zn, and Cu in leaves. There was no ASF effect on bulb quality. NDVI indicated that applying 225 kg ha− 1 ASF to soil promoted healthier onion plants and the highest yield. Conclusions Silicon increased the yield of onions due to improved plant nutrition and stress amelioration.