Across Northern Ireland, 2019 will be remembered as a super grass growing year, despite the wet finish to the grazing season in autumn.

A mild winter in late 2018 and early 2019 meant most livestock farms carried heavy covers of grass into the spring.

Favourable weather conditions in May saw grass growth surging ahead of demand and farmers were faced with the problems of dealing with so much grass.

Store cattle prices received a boost, as did store lambs, as farmers looked to convert surplus grass into cheap liveweight gain once silage reserves had been fully replenished.

Grass yields

On the BETTER Farm NI programme, grass measuring was carried out on a weekly basis from spring until autumn on four of participating farms.

Across the four farms, grass growth in 2019 averaged 41kg DM/ha/day over a 240-day season. Grass yields averaged 9.77t DM/ha DM across the farms, up from 8.7t DM/ha last year and 7.4t DM/ha in 2017, giving a 32% yield increase over the three-year period. Grass growth on the average Northern Ireland farm would be closer to 7.5t DM/ha.

While weather ultimately dictates growing conditions, grass yields will not increase unless soil fertility is being improved.

Throughout all three phases of the programme, increasing soil fertility has been one of the cornerstones of the farm development plans.

Rewards

The trend of increased grass yield year on year indicates that the investments made in improving soil fertility are now paying off.

Regular lime applications, improving soil organic matter and using more expensive phosphate- and potash-based fertilisers come at a cost.

However, the increased grass growth and yields are now supporting higher stocking rates on the programme farms, on the same size of grazing platform.

Stocking rates have increased on the four farms from 1.81 CE/ha in the base year of 2016 to 2.21CE/ha in the past year.

Higher stocking rates mean greater grazing pressure. As such, grass utilisation has increased along with the herds selling more kilograms of liveweight annually.

Improved grassland production has also extended the grazing season, with greater growth in early spring and late autumn, thereby reducing wintering costs.

Yield increase

Table 1 outlines grass growth and yield on the four farms over the last three years. In 2019, Oliver McKenna had the highest average yield at 12.09t DM/ha, up from an impressive 10.35t DM/ha last year and 8.89t DM/ha in 2017.

Oliver’s farm at Eskra excels at growing grass, due to a combination of soil type and fertilisers applied. Soils are well managed, and would be heavier than all, bar one, of the programme farms. These heavier soils retain soil moisture better, meaning grass growth really accelerates during periods of warm, dry weather.

Yields within individual paddocks ranged from a superb 15.3t DM/ha down to 6.9t DM/ha. Paddock yields will vary due to soil type, drainage, sward type and age, north or south facing, soil fertility and fertiliser use.

Highest paddock

The highest-yielding paddock on the four farms was on Declan Rafferty and Aidan Quinn’s unit at Pomeroy.

While the farm averaged 10.8t DM/ha this year, individual paddocks ranged from 16.5t DM/ha back to 5.5t DM/ha.

The two highest yielding farms are located in the western half of the province, where the automatic impression is that growing conditions are not less favourable than the eastern half.

However, both farms clearly demonstrate that well-managed swards will perform, regardless of geographical location.

Long-term investment

It is noticeable that grass yields on both farms located in Co Tyrone are significantly higher than those in Co Down and Co Derry.

A key factor that has influenced higher yields is the time spent in the programme. Both farms in Tyrone have been involved with the programme for six years, whereas Paul Jamison and Jonathan Blair have only been involved for the three years in the current phase.

This means the Tyrone farms have been focusing on improving soil fertility and grassland management for longer.

Wet autumn

Grass yield on Jonathan Blair’s farm was lower in 2019 compared to the previous year and this reflects challenging weather conditions during September and October when grass growth tailed off quickly.

In addition, the farm has the lowest stocking rate of the featured farms. As such, once winter fodder reserves were fully replenished by mid-summer, fertiliser applications were reduced to avoid further grazing surpluses emerging.

Grazing groups increased as cattle were spread out over a greater area on farm in an effort to keep late summer grazing in check.

Paul Jamison’s is the driest unit of the four. During prolonged dry spells, like those experienced this spring and early summer, grass growth tends to suffer as the lighter soils are less capable of holding moisture.

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