Brynllech Project Update - December 2024

What has been done since the previous update?

• Average dry matter availability of herbage biomass per ha from 29 June 2024 to 4th December calculated using the following cut and weigh method;
  • Herbage biomass availability was measured monthly from June-December by placing three 1m x 1m exclusion cages at random in each plot and cutting herbage present within a 0.5 x 0.5 m quadrant to a height of 4 cm.
  • Herbage recovered was weighed to determine fresh weight before drying in a microwave until a constant dry weight was achieved.
  • Results were upscaled to determine the average dry matter availability of herbage biomass per ha each month.
     
• Snap-shots of forage nutritional quality were taken on the 31 July and 1 October using the following method with results shown in Table 1.0 and 1.1;
  • Herbage samples taken from within exclusion cages and pooled to give 1 sub-sample for each plot.
  • Samples sent to Sciantec Analytical (Sciantec, Yorkshire, UK) for NIR (Near InfraRed) analysis to determine the Dry Matter (DM), Crude Protein (CP), Metabolisable Energy (ME), Neutral Detergent Fiber (NDF) and Ash contents of swards.

Figure 1 showing the locations of grazing exclusion cages across the plots; Permanent Pasture (0), Diverse Grass and Clover (1), Multispecies (2)

Outputs

Total forage herbage biomass growth

• As can be seen in Figure 2, the diverse grass and clover plot grew the most amount of forage herbage biomass between the 29 May and 4 December 2024 at 6534.8 kg DM/ha, while the permanent pasture plot grew the least amount of forage herbage biomass during the same period at 3618.1 kg DM/ha. Data was lost while taking samples for nutritional quality on the 1st of October, so September growth is excluded from all results.

  

Figure 2: Total average forage herbage biomass growth (Kg DM / ha) from 29 May to 4 December* for all trial plots; Control (Permanent Pasture), Plot 1 (Diverse Grass and Clover), Plot 2 (Multispecies) and Plot 3 (PRG and White Clover).* data lost from 1 October cut and weigh session.

Growth throughout the year

• Growth peaked in June for the diverse grass and clover plot and the multispecies plot, while growth peaked in July for the PRG and White Clover plot and permanent pasture plot as can be seen in figure 3.

• Figure 4 compares the 2 months with the highest forage demand on the farm, June and July, where most pressure is applied to the fields included in the trial. Figure 4 shows that all reseeded plots grew over 1500 kg DM/ha more forage herbage biomass than the undisturbed permanent pasture plot, while the diverse grass and clover plot grew more than double the forage herbage biomass of the permanent pasture plot during these months.

•  months.

Figure 3: Average forage herbage biomass growth (Kg DM / ha) from 29 May to 4 December* for all trial plots; Control (Permanent Pasture), Plot 1 (Diverse Grass and Clover), Plot 2 (Multispecies) and Plot 3 (PRG and White Clover).

* Data lost from 1 October cut and weigh session.

Figure 4: Average forage herbage biomass growth (Kg DM / ha) for the months of June and July 2024 for all trial plots; Control (Permanent Pasture), Plot 1 (Diverse Grass and Clover), Plot 2 (Multispecies) and Plot 3 (PRG and White Clover).

Forage Quality

• Forage NIR analysis for all sub-samples taken on the 1 October were very similar as can be seen on table 1.1. However as can be seen in table 1.0 the analysis of the sub-sample sent from the multispecies plot on the 31 July showed a higher ME content than the rest of the plots at 11.1 MJ/kg.

Table 1.0: Herbage sub-sample analysis for each plot. Samples taken 31 July 2024

Table 1.1: Herbage sub-sample analysis for each plot. Samples taken 1 October 2024