This week we profile a farmer who is measuring his grass every week of the year. By recording weekly growth rates, a summary of annual growth rate per paddock can be generated. The paddocks that are performing or not can then be easily picked out.

Here we analyse the 2014 results for Sean Roberts, a farmer near Old Ross, Co Wexford (Figure 1).

Soil type is dry with a shale base, and it usually performs best during average or above-average rainfall years.

It does not perform well during very dry years.

Results

Figure 1 illustrates the annual tonnes grown for each individual paddock on this Wexford farm. Paddock 14 grew the most grass at 18.6t DM/ha. It was reseeded in May 2013 with a Germinal Seed Top 5 Extend Mix, which included Abergain, Aberchoice and Tyrella.

Looking at the other paddocks, it is clear to see performance was very good overall in 2014, with eight paddocks exceeding 16t DM/ha/year. Some paddocks didn’t perform as well and the poorest paddocks (2 and 3), grew 10t DM/ha/year.

The reason these paddocks didn’t rank high in total tonnage this year is because they were out of production for a period for drainage and reseeding work.

Lessons

By measuring and recording results weekly, Sean is in a position to make educated decisions as to what paddocks need attention in the coming year. On average this year, he grew 15.41t DM/ha/year.

He is happy with his overall performance, but feels some paddocks are lagging behind and could do better. By looking at the results (Figure 1), it is clear that paddocks two and three grew the least amount of grass this year due to the reseeding, but next year with suitable weather conditions and a suitable fertilizer programme, they should be capable of growing as much grass as the top performers.

Sean also plans to reseed number 16 next year. This paddock lies over a shale quarry and can suffer from drought. It grew 13.2t DM/ha this year, which is 14% below the average total grown. The last time it was reseeded was in 2006. The farmer’s objective is to increase the overall amount of grass grown on the farm by monitoring individual paddock growth and implementing changes where needed to boost performance on paddocks that aren’t growing enough grass to reduce the overall variability between paddocks.

Improving performance

Once you identify paddocks that are underperforming, you can make management decisions to improve grass production. Some people might say that if the paddock (number 16) grew 13t DM/ha this year, why would you bother reseeding? It’s not a bad result.

The reason Sean should reseed this field is because every extra tonne of grass utilised equates to €160/t extra profit. Reseeding can play a huge role in increasing overall paddock performance.

Farmers with annual paddock yields with less than 50% production of their best paddocks should look at why this is the case.

Research carried out by Teagasc showed that, on average, swards with a high abundance of perennial ryegrass grew 3t DM/ha/year more grass compared to old permanent pastures.

Taking the cost of reseeding at €750/ha, it would take just two years to get a payback on the investment made. The Wexford farm soil test results show 50% of the farm is soil index two and 50% is in soil index three. Sean is continually trying to raise the indices by spreading compound fertilizers rather than straight nitrogen. The soil pH is 6.5, which is ideal for growing grass.

When reseeding land, it is very important to know what the fertility is like. Perennial ryegrass will not survive in poor-fertility conditions. Table 1 illustrates the required amount of Phosphorus (P) and Potassium (K) that should be applied to a newly reseeded sward depending on its fertility status.

The lower the fertility of the soil, the more P and K that is required. Drainage also has a role to play in improving paddock performance, especially in the shoulders of the year.

Before you carry out an expensive drainage job, you should make sure all other paddocks are performing to their ability. There is no point spending a lot of money draining wet ground when the rest of the farm could be utilised better with a lower investment.

Thanks

We would like to take this opportunity to thank everyone that contributed to Grasswatch throughout the year. The supply of growth rate figures and weekly management notes are invaluable and really aid management decisions for our readers. Wishing you all a Merry Christmas and a happy New Year.