This was a very challenging year in terms of weather and grass growth. Rainfall was 142% higher than average for February, March and April, with sunshine hours also well below average.

In contrast, rainfall in May, June and July was only 81% of the average, with huge variation in this figure as the northwest had above-average rainfall, whereas the midlands, south and east had below-average rainfall. Summer temperatures were also below average.

Data from the Moorepark clover research experiment shows that the grass production for 2024 on the grass-clover sward receiving 150kg nitrogen (N)/ha, was 11.2t dry matter (DM)/ha, a 19% reduction compared to the five-year average (13.8t DM/ha).

In contrast, the grass-clover sward receiving 150kg N/ha in the Clonakilty clover research experiment produced 14.5t DM/ha, a 1% increase on the five-year average (14.3t DM/ha).

Both research experiments have been using urea plus NBPT for all of their straight N requirements for the last number of years. Nationally, grass production was down by 1.1t DM/ha to 11.3t DM/ha in 2024, with large variations across the country.

Table 1 highlights some of the variation observed between locations, regardless of the fertiliser type used.

Plot study

Data from a plot study undertaken in Moorepark and Clonakilty in 2024, showed no difference between CAN and urea plus NBPT, under a grazing scenario, in terms of pre-grazing yield (1,603 v 1,553kg DM/ha for CAN and urea plus NBPT, respectively; Table 2) or total grass DM production (11.4 v 11.3 t DM/ha for CAN and urea plus NBPT, respectively; Table 2).

In 2024, in Moorepark, soil N mineralisation was reduced by 30kg/ha (16%) compared to previous years, due to the poor weather.

This effect was exacerbated in grass-clover swards as biological N fixation was also reduced by 50kg/ha (approximately 50%) in 2024.

  • 2024 was a very difficult year for grass growth in many areas of the country.
  • There was no difference between CAN and urea plus NBPT in terms of grass growth in 2024.