Our Organisation Search
Quick Links
Toggle: Topics

Grassland - Beef


Nitrogen (N) fertilizer advice for grazing

Rates and timing of N fertilizer applications for swards grazed by suckler calf to weaning at various stocking rates. Rates of fertilizer N are shown as kg/ha. Refer to Teagasc Green Book for N advice for other dry stock systems.

See link to Early N Advice Guidelines for efficient use & response https://www.teagasc.ie/publications/2022/when-to-apply-early-nitrogen-n.php

Nitrogen (N) requirements for pasture

  • There is no reliable soil test currently available for N. Therefore, there is no soil Index system for N in grassland.
  • Recommendations are based on average soil fertility levels.
  • Total N application and on the farm and time of application must be compliant with nitrates regulations.
  • Matching nitrogen fertilizer use to stocking density on the farm at different times of the year avoids excessive use.
  • Applying nitrogen fertilizer ‘little and often’ during the growing season gives most efficient response in terms of grass growth.

Phosphorus (P) for drystock grazed swards*

  • Rates shown must be deducted to account for P fed to livestock in concentrate feeds
  • Adjust rates based on slurry management as per fertiliser plan.
  • To account for P in concentrate feeds, use either actual P content in the feeds used if available, or alternatively, use a default value of 5 kg of P per tonne of concentrate feed.
  • Complete a farm fertiliser plan to determine farm N & P allowances.

Fertiliser Values for Cattle Slurry


Figure 1. Grass yield responses to sulphur applied on a range of soil types.  Grass yield responses to S range from 1.0 to 3t/ha from heavy to light soil types.

  • Sulphur (S) is an important nutrient for grassland, and is closely associated with N uptake and efficiency.
  • There is currently no soil test or soil Index system for S.
  • Herbage analysis is the best predictor of S deficiency.
  • Lighter soils with low organic matter contents are generally more prone to S deficiency.

Figure 2. Map indicating areas of possible S deficiency

S fertiliser advice

  • The response to S fertiliser increases as the rate of N fertiliser increases.
  • On S deficient soils, apply 20 kg/ha per year for grazed swards.
  • For silage swards on S deficient soils, apply 20 kg/ha of S per cut.
  • Avoid S application to soils not deficient in S, as excess S may affect the trace element nutrition of plants and animals.
  • S can be applied by using any of a number of straight or compound fertilizers that contain S.
  • Aim to apply S containing fertilisers from March / April to June