When we think about the factors that determine a cereal crop’s final yield, attention typically goes to mid-season management, fertiliser regimes, and stress events. But the evidence is increasingly clear: what happens in the first 10–14 days after germination sets the trajectory for everything that follows.
Early seedling establishment, the window between germination and the unfolding of the first leaves, is the stage at which wheat and barley are most vulnerable. Nutrient deficiencies during this period don’t just slow growth; they can trigger cascading physiological consequences that compromise the entire season’s potential.
This is the problem this paper sets out to investigate, published this month in Frontiers in Plant Science.
The Question Nobody was Asking
A significant body of literature exists on how seaweed-based biostimulants affect mature crop plants: nitrogen uptake, stress tolerance, yield at harvest. But a crucial gap remained: what do these biostimulants do to micronutrient dynamics in very young seedlings?
Micronutrients, boron, zinc, iron, manganese, copper, molybdenum, are required in tiny amounts, but their roles are anything but minor. They govern chlorophyll biosynthesis, antioxidant defence, enzyme activity, carbohydrate generation, and reproductive development. A deficit at the seedling stage, before root systems are established enough to access soil reserves, can leave lasting damage.
Our study is the first to provide a comprehensive, integrated assessment of micronutrient uptake and remobilisation in wheat and barley simultaneously, during early seedling growth, under controlled conditions.
Comparing 3 Commercial Extracts
The study begins with a head-to-head comparison of three commercial Ascophyllum nodosum extracts (ANE A, ANE B, and ANE C), standardised by total solids content so that differences in biological activity, not formulation concentration, could be assessed fairly.
The compositional differences between the extracts were substantial. ANE A contained significantly higher levels of uronic acids (alginates) and fucoidan than ANE C, and matched ANE B in several parameters including ash, laminarin, free mannitol, and polyphenols. ANE C consistently showed the lowest values across all measured components.
But composition alone didn’t predict performance, which is itself an important finding.
ANE A and ANE C both increased total wheat biomass by approximately 21-23%
However, their effects were strikingly different in character. ANE C primarily drove shoot growth (+20.6%), while ANE A produced a dominant effect on root biomass (+41.1%). In cereal production, early root growth is not just a number, it is the architecture underpinning nutrient and water capture for the entire life cycle of the plant.
ANE B produced no statistically significant effect on biomass at all, despite sharing four compositional parameters with ANE A. This confirms a principle we have been building evidence for across our research programme: extract composition alone does not predict biological efficacy. The efficiency of a biostimulant is shaped by the concentration and molecular size of its active components, not simply by which fractions are present. Based on its superior performance across biomass and nutrient content metrics, ANE A was selected for detailed mechanistic investigation.tions that enhance natural plant defence and recovery mechanisms will be essential. This research highlights the important role that marine-derived biostimulants can play in safeguarding crop performance and ensuring yield stability.
ANE A: Next Steps
The second phase of the study examined ANE A applied to both winter barley and wheat seedlings under two nutrient conditions:
0 MS: nutrient-free medium (seedlings rely entirely on internal seed reserves)
1/10 MS: a reduced-nutrient medium (approximately 10% of standard Murashige-Skoog formulation)
ANE A was applied either as a foliar spray or directly to the root system via incorporation into the growth medium. This gave four treatment combinations per crop, a design that allowed us to disentangle the effects of nutrient availability, application route, and species.
Root biomass increased consistently. Foliar ANE A increased root biomass by 12.2% in barley and 26% in wheat across both nutrient conditions. Root application produced increases of 13.3% and 20.1% respectively. The effect was statistically significant regardless of whether nutrients were present in the medium.
Nutrient remobilisation from seed reserves was demonstrated directly. Under nutrient-free (0 MS) conditions, where no external minerals were available, ANE A still increased total nutrient content in seedling tissues. This can only be explained by enhanced mobilisation and redistribution of nutrients stored in the seed itself. In other words, ANE A doesn’t just help plants take up nutrients that are available in the soil; it helps plants deploy their own internal reserves more effectively during the critical early establishment window.
Macro, Secondary, and Micronutrient Responses
The nutrient profile of ANE A-treated seedlings was analysed tissue by tissue, roots and shoots separately, using ICP-MS. The findings reveal a nuanced, crop-specific picture.
Potassium and phosphorus showed the most consistent responses. K which is essential for osmotic regulation and root development increased in both roots and shoots across nutrient conditions, with particularly strong effects in wheat even under nutrient deprivation. P, central to early root vigour, followed a similar pattern across tissues and conditions.
Calcium and magnesium showed more application-dependent responses. Ca increased primarily in shoots, pointing to enhanced translocation rather than simple root uptake. Mg showed opposite patterns depending on application route, foliar treatment favoured root accumulation while root application favoured shoot accumulation, illustrating how the delivery method actively shapes nutrient partitioning.
Micronutrient responses were the most striking findings. In wheat, foliar ANE A consistently elevated root Cu (+28%), Zn in both tissues (+19% root, +16% shoot), and shoot Fe (+17%). Under the 1/10 MS regime, root B increased by +11%, root and shoot Mn by +36%, shoot Cu by +31%, and root/shoot Mo by +36%. In barley, foliar application under nutrient-free conditions produced remarkable effects: root B +43%, Cu +43%, Fe +66%, and Mo +71% in shoots.
These are not marginal improvements. Iron and zinc are central to antioxidant defence and energy metabolism. Manganese underpins photosynthesis. Molybdenum drives enzymatic processes including nitrogen assimilation. Boron supports cell wall integrity and pollen viability. Improving the mobilisation and allocation of all of these simultaneously, in a 12-day-old seedling, is a meaningful advance.
Measuring Nutrient Use Efficiency
To quantify these effects rigorously, two established NUE indices were applied, Recovery Efficiency (RE) and Agronomic Efficiency (AE), adapted from field fertiliser science to our controlled system. RE measures how much of the available nutrient is actually taken up by the plant. Foliar ANE A in wheat drove RE increases of +46% for K in roots, +78% for Mg in roots, +118–130% for B in both tissues, +9.9-fold for Ca in roots, and +36% for Mo in both tissues. Root-applied ANE A in wheat increased Fe RE by +71% in roots and +5.5-fold in shoots. AE measures the improvement in biomass resulting from each unit of nutrient input. ANE A increased root AE by +41% in barley and +39% in wheat when applied via foliar application. Root application drove even larger gains, +89% in barley roots and +45% in wheat roots. The consistent pattern across both metrics is that ANE A improves not just the quantity of nutrients taken up, but the productivity of each unit of nutrient available to the plant.
Wheat vs. Barley: Species Differences Matter
One of the more practically useful findings of the study is the clear distinction in how the two crops responded.
Barley showed more root-focused responses: foliar application enhanced root accumulation of K, Ca, B, Mn, and Mo, while root application stimulated translocation to shoots for Ca, B, Fe, and Zn. This root-dominant strategy is consistent with barley’s known adaptation to stress-prone environments and its tendency to prioritise below-ground resource acquisition.
Wheat showed broader, more systemic enhancement. Both roots and shoots benefited across a wider range of nutrients, with simultaneous increases in mobile nutrients (K, P, Mg) and less mobile elements (B, Fe, Cu, Mo). This indicates efficient systemic redistribution, an important trait for crops where shoot nutrient density directly contributes to grain quality.
The practical implication: optimal ANE A application strategy may differ between crops, and between the objectives of a given growing system.
What This Means for Sustainable Cereal Production
Nutrient use efficiency is one of the defining challenges of modern agronomy. The environmental and economic cost of nutrient losses through leaching, volatilisation, and runoff is substantial. At the same time, the pressure to maintain or increase yields with reduced inputs is intensifying.
Biostimulants like ANE A offer a tool to enable plants to use the nutrients available to them more effectively. The evidence from this study suggests that early application during seedling establishment, targeting the window when root systems are forming and seed reserves are being deployed, may be one of the highest-leverage intervention points in the crop calendar.
Read the Full Paper
The paper is open access and available now:
Ikuyinminu E, Goñi O, Łangowski Ł and O’Connell S (2026) Impact of Ascophyllum nodosum extract biostimulants on nutrient use efficiency and seedling establishment in wheat and barley. Front. Plant Sci. 17:1813433. https://doi.org/10.3389/fpls.2026.1813433
