Grassland

Dairy

Nitrogen fertiliser advice for dairy grazing

Rates and timing of N fertilizer applications for swards grazed by cattle at various stocking rates. Rates of fertiliser N are shown as kg/ha (units/acre in brackets).

See link to Early N Advice Guidelines for efficient use & response Grasslandhttps://www.teagasc.ie/media/website/environment/soil/Early-Nitrogen-Advice---Grassland.pdf

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 dairy grazed swards*

Table 2:- Simplified P requirements (kg/ha) of grazed swards on dairy farms. (Rates shown are total P requirements, before deductions for concentrate feeds or organic fertilizers).

Note

Rates shown must be deducted to account for P fed to livestock in concentrate feeds.
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.

Potassium (K) for dairy grazed swards*

Table 3:- Simplified K requirements (kg/ha) of grazed swards on dairy farms. (Rates shown are total K requirements, before deductions for organic fertilizers).

Fertiliser Values for Cattle Slurry

*The P and K rates shown can be supplied by either slurry or fertiliser

Sulphur

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.

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.

Fertiliser Requirements at P & K Indexes 1 to 4 & Suggested N, P & K Programmes

Fertiliser programme showing splits & fertiliser products & N, P & K timings

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 (units/acre in brackets)

See link to Early N Advice Guidelines for efficient use & response. Grasslandhttps://www.teagasc.ie/media/website/environment/soil/Early-Nitrogen-Advice---Grassland.pdf

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 cattle grazed swards**

Table 2:- Simplified P requirements (kg/ha) of grazed swards on dairy farms. (Rates shown are total P requirements, before deductions for concentrate feeds or organic fertilisers).

Rates shown must be deducted to account for P fed to livestock in concentrate feeds.
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.

Potassium (K) for cattle grazed swards**

Table 3:- Simplified K requirements (kg/ha) of grazed swards on dairy farms. (Rates shown are total K requirements, before deductions for organic fertilisers).

*The P and K rates shown can be supplied by either slurry or fertilizer

Fertiliser Values for Cattle Slurry

*The P and K rates shown can be supplied by either slurry or fertiliser

Sulphur

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.

S fertilizer 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.

Fertiliser Requirements at P & K Indexes 1 to 4 & Suggested N, P & K Programmes

Fertiliser programme showing splits & fertiliser products & N, P & K timings

Sheep

Nitrogen (N) fertiliser advice sheep grazing

Table 1 gives guideline rates for N applications on sheep pasture with normal to low clover content for a range of stocking rates. The suggested timetable applies to ewes with high productivity assuming that no concentrates are offered at pasture. The N timetable is for early to mid-March lambing, but depends on several factors including overall farm system, soil, climatic conditions, clover content etc.

The N requirements for sheep grazing are generally lower than for dairy cows or cattle. This is because:

Less silage is required for sheep than for cattle due to the shorter in-wintering period
Sheep recycle dung/urine more uniformly to pasture and hence there is less herbage waste around dung-pats and, consequently, more efficient herbage utilisation (more uniform post-grazing height and less high grass left ungrazed)
There is a better match between feed demand and herbage growth because feed demand is highest from lambing to weaning (March to early July). It decreases post weaning as lambs are drafted for sale and ewes can be restricted to maintenance feeding
Clover survival can be encouraged by rotational grazing rather than continuous sheep grazing as sheep preferentially graze clover plants