Farmed kelp is a help for wheat yield
Seaweed extract shown to boost crop in experiment
A biostimulant that is extracted from farmed sugar kelp by using a low-energy process been seen to increase wheat yield, say UK researchers.
An experiment to determine the optimal application rate of the biostimulant, called TD65, resulted in enhanced plant growth and a 24% increase in wheat grain yield, as well as a 45% increase in grain number, compared to plants grown under the same conditions but without TD65.
The experiment was part of a project led by seaweed biotech business Algapelago Marine Limited, which collaborated with Hertfordshire-based farming institute Rothamsted Research and the UK Agri-Tech Centre.
Biostimulants
Interest is growing in the use of seaweed-derived biostimulants in agriculture due to their potential to enhance crop growth, promote stress tolerance and increase nutrient use efficiency, and because they are derived from a sustainable source with positive environment impacts.
Current agri-seaweed products are dominated by seaweed sourced from wild harvest and the demand for seaweed-derived soil and animal supplements is expected to grow exponentially as policy drives a reduction in chemical fertiliser inputs.
However, the biochemical mechanisms involved in the seaweed products’ beneficial impacts on crops remain poorly understood.
Algapelago, which operates a pilot site four miles off the North Devon coast and is the UK’s largest licensed kelp cultivator, has developed a low energy method for extracting biostimulants from farmed seaweed that provides a biostimulant product of consistent quality with potentially significant commercial value.
Two experiments
In order to establish optimal application methods and rates for Algapelago’s TD65 biostimulant, two experiments were conducted in controlled environment facilities.
The first investigated the impact of four different rates of foliar applications on wheat and field bean yields under both well-watered and drought-stressed conditions, and the second investigated whether foliar application or soil application had the greatest impact on yields of wheat.
The aims of the first experiment were to determine the optimal application rate of TD65 under ambient conditions, and also to see if there were any yield benefits when plants were drought stressed.
The second experiment was conducted to try to identify if the benefits of the biostimulant were due to direct plant physiological impacts, or if any benefits were due to stimulation of soil microbial activity and consequent increases in nutrient availability and uptake efficiency.
Crop yield benefits
Although the application rate experiment resulted in increased wheat grain and grain number yield, no benefit of the biostimulant application was observed in the drought-stressed plants.
This result has validated our belief in the quality of our cultivated sugar kelp and extraction method.
In the application method experiment, the application method didn’t affect the yields of wheat in either growing medium, although the plants grown in the hydroponic system significantly outperformed those grown in soil.
Overall, there is evidence that seaweed-derived biostimulants can, under certain conditions, provide crop yield benefits.
Significant milestone
Luke Ansell, head of operations at Algapelago Marine, said: “The completion of the Rothamsted crop trials is a significant milestone for the project and wider product development.
“We are thrilled to see a 24% yield increase in wheat grain due to this prototype sugar kelp extract.
“This result has validated our belief in the quality of our cultivated sugar kelp and extraction method.
“While we await the full analysis results from this study, a wider trial program is underway across soft fruits, field and root vegetables which will further build the evidence base for product efficacy.”
The project builds on previous feasibility studies to optimise the liquid extraction and ensiling of kelp, developing a novel two-stage extraction process which produces consistent agricultural products.
