Can Foliar Silicon Application Increase Sugar Beet Leaf Yield as a Forage Source?

The declining profitability of sugar beet production in Europe has increased interest in alternative uses of by-products such as leaves. Climate change is also exacerbating constraints on forage production for beef cattle, and sugar beet leaves may provide a valuable feed resource. A three-year field experiment conducted in southeastern Poland evaluated the effects of a single foliar application of three silicon forms—calcium silicate (CS), sodium metasilicate (SM), and micronized silica (MS)—applied at the six-leaf stage (BBCH 16), 7 or 14 days later, at the standard or double product dose, on sugar beet leaf fresh matter (FM) and dry matter (DM) yields. Leaf FM yield was significantly affected by year, silicon form, the year × silicon form interaction, and the year × silicon form × application timing interaction. Leaf DM yield was additionally affected by the year × silicon form × dose interaction. Among the tested products, CS produced the highest overall leaf FM and DM yields, averaged across years and application treatments. These results quantify product-related differences in sugar beet leaf biomass under the tested conditions. Significant interactions limit generalization across years; feeding value and whole-crop profitability require assessment before practical forage recommendations can be made.