Spring Nitrogen is essential for grass growth on beef farms – Teagasc
Nitrogen applications are essential for grass growth on beef farms this spring, according to Teagasc’s Ned Heffernan.
The Business and Technology Drystock Advisor said that farmers should aim to apply 23 units of Nitrogen (N) in February.
The beef specialist also said that highly stocked farms should spread 60 units of N by early April, which will allow for adequate grass growth in the second and third rotation.
The average spring N response is 10kg of grass dry matter for every 1kg of N applied.
Farmers should target their most productive swards or recently reseeded swards with early N applications, he said.
Urea verses CAN fertiliser
Heffernan also spoke about the cost difference between urea and Calcium Ammonium Nitrate (CAN). He said that urea costs 75c/kg of N, which is cheaper than CAN (€1/kg of N), at current market prices.
Research from Teagasc shows that there is no difference in the grass growth response from urea or CAN, but urea may be a more efficient fertiliser in the spring time.
“Urea may be safer than CAN fertilisers for early N applications because there will be less nitrate lost, nitrate is prone to leaching in the soil,” he said.
However, the application of Nitrogen to grassland is dependent on a number of key factors. These include location, soil conditions, temperature and the length of the growing season.
Nitrogen should be applied when soil temperatures reach 5-6 degrees Celcius, as this is when grass begins to grow.
Farmers should check the forecast prior to spreading fertiliser to ensure that there at least 48 hours of reasonable weather after application, he said.
pH, P and K key for grass growth
Heffernan also discussed the importance of maintaining good pH, Phosphorous (P) and Potassium (K) levels.
He said that fields that have a low pH should be targeted first with lime to address the pH deficit. Correcting the soils pH has the potential to release an additional 80kg of N/ha on an annual basis, he said.
The Teagasc advisor also that soils that are low in P and K will have a lower response to N fertiliser applications, and so these paddocks or fields should be targeted with compound fertilisers or slurry.