Biostimulant effects on the herbage yield and nutritive composition of a mixed ryegrass–clover pasture

Abstract

Dairy producers are continuously searching for environmentally friendly and economically sustainable alternatives to increase pasture  herbage yield and reduce reliance on chemical fertilisers. A possible means to reduce fertiliser reliance is the use of biostimulants.  Biostimulants such as fulvic acid and bioflavonoids help to increase N uptake efficiency, thereby increasing herbage quantity and quality.  The aim of this study was to determine the effects of a soil application of a carbohydrate-derived fulvic acid and bioflavonoid biostimulant  on herbage yield and nutritive composition of a mixed perennial ryegrass–clover pasture. Biostimulant treatment resulted  in a lower ryegrass component of the mixed sward, in both winter and summer grazing cycles. However, the nutritive composition and total herbage yield of the pasture were not significantly affected by biostimulant treatment. The treatment did show a tendency to affect  total herbage yield within a season. This suggests that total herbage yield could be increased if additional N fertiliser is applied together  with a biostimulant soil treatment, although further investigation is needed to confirm this postulation. Biostimulant treatments have the  potential to lead to reduced fertiliser inputs on perennial ryegrass–clover pastures as they may increase nutrient uptake efficiency.