Tanygraig Project update - Final
Key results:
- The use of Seaweed biostimulant saw an increased yield of 733 kgDM /ha in the direct drilled plot and 498 kgDM /ha for the Opico harrowed plot, equating to an average increased output of £92.33/ha.
- There was little difference between the direct drilled and Opico broadcast treatments in terms of clover presence and yields.
- The success of overseeding may have been improved by delaying the timing to after silage production rather than spring.
Background:
With the production and environmental benefits of diverse swards growing, the case for mixing clover, in particular red clover with grass seed is becoming increasingly compelling. The high protein content of red clover is one of its greatest attributes for producing high-quality silage. In addition, it’s also considered beneficial for its nitrogen-fixing ability, reducing the requirement for applied nitrogen. The use of seaweed-based bioproducts has also been gaining momentum in crop production systems owing to their unique bioactive components and effects. Over the decades, seaweed extracts have been highly explored for possible use in crop production for improving biomass yield and produce quality. These extracts have been shown to positively affect seed germination and plant growth at all stages up to harvest and even post-harvest.
Purpose of the work:
- Investigating the effect of incorporating a seaweed-based bioproduct onto a red clover ley to understand the effect on establishment, growth and quality of the crop
- To produce better quality silage for winter feed for growing cattle by improving resource efficiency by making the most of home-grown forage on farm and contributing to high herd health and welfare and to calculate the economic benefit to the business of finishing cattle from home grown forage.
- Reduce the need to purchase artificial fertiliser which improves resource efficiency
What we did:
Three fields (0.81ha, 0.87ha and 1.02ha) with similar past management were used with each field having 4 trial plots. The four plots can be seen in Figure 1 below.
Figure 1- Layout of plots in each field.
As seen in figure 1, the plots were split into direct drilled with seaweed biosimulant, direct drill only, broadcast using the Opico harrow with seaweed biostimulant and broadcast using the Opico harrow only.
Table 1. Timeline of project.
On 22 April, all red clover plots were overseeded with the red clover blend from Field Options at a rate of 3kg/acre using the opico or direct drill. Due to a delay with the seaweed bio-stimulant arriving at the farm, it was not applied to the first cut silage which was done in June as seen in the project timeline (table 1). Two applications of the 4% concentration seaweed were applied three weeks apart at a rate of 7.5litres/ha/application using the farms tractor mounted sprayer. Silage analysis was also done on both cuts. Grass yield measurements were then taken across each of the plots and samples were also taken to assess the dry matter, ME and CP of the cut grass.
Outcomes:
Figure 2. Fresh grass analysis with and without seaweed biostimulant.
Table 2. Fresh grass analysis with and without seaweed biostimulant.
The fresh grass analysis can be seen above in graph 2 and table 2 with the results indicating a slight increase in the grass quality for the seaweed treated plots compared to the control. Crude protein levels sit at 149.5g/kg compared to 130g/kg, d-value is at 65 compared to 61.35 and finally sugar levels are also higher at 125g/kg compared to 112g/kg.
Figure 3. Silage yields of the different plots (kg/DM ha)
As seen in figure 3 above, there was little difference between the direct drilled and Opico broadcast treatments with the direct drill seeding method having a slightly higher yield by 49kgDM/ha. The reduced yield in Opico broadcast sward may have been due to increased disturbance of the current sward which in turn led to a lower yield.
However, the use of the seaweed foliar feed increased the yield substantially per hectare for both plots with an increased yield of 733 kgDM/ha in the direct drilled plot and 498 kgDM/ha in the Opico broadcast treatment. With a price of approximately 15p per kg of dry matter for silage this would have increased output per ha by £92.33.
When overseeding, direct drilling and broadcasting both works well as a means of establishment. The Opico harrow did cause more damage to the existing sward which did reduce the overall silage yield. However, this did help with the establishment of the red clover due to the sward not being quite as competitive against the new seeds. In terms of establishment the red clover did struggle to establish in the silage leys particularly in the spring when the swards were fertilised. Ideally the establishment of red clover should happen after a cut of silage to allow it to establish in the aftermath.
The seaweed clearly increased yield potential across the plots and acted as a bio-stimulant. Further trials will take place in 2025 to see if the benefit of the foliar feed continues into future cuts and throughout the season.
How to apply on your farm:
1. Timing is important – post harvest is preferred with mid-September being the cut-off point.
2. Soil pH should be at minimum of 6 and soil chemistry corrected prior to drilling.
3. When the seed is drilled, there should be moisture in the soil and rain in the forecast.
4. Select the right drill for the job as a heavy drill can sow seed too deeply – clover should not be drilled deeper than 1cm.
5.Care must be taken in how clover is managed in the eight weeks after sowing. Graze for no more than a day to take off the top 4cm. Graze again two weeks later in a similar way, to avoid grass shading out the young clover plants.