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Grassland - Beef

Beef

N fertiliser advice for grazing

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

N fertiliser advice for cattle grazing
Stocking Rate (kg Org N/ha)Jan
/Feb
MarAprilMayJunJulAugSeptTotal N Rate
≤ 70 0 (0) 0 (0) 0 (0) 0 (0) 0 (0) 0 (0) 0 (0) 0 (0) 0 (0)
71 - 90 0 (0) 0 (0) 25 (20) 0 (0) 15 (12) 15 (12) 0 (0) 0 (0) 40 (32)
91 - 110 0 (0) 15 (12) 30 (24) 15 (12) 15 (12) 15 (12) 0 (0) 0 (0) 75 (60)
111 - 130 0 (0) 28 (22) 35 (28) 25 (20) 23 (18) 0 (0) 111 (89)
131 - 140 0 (0) 28 (22) 35 (28) 25 (20) 17 (14) 17 (14) 122 (98)
141 - 150 0 (0) 29 (23) 44(35) 26 (20) 26 (20) 17 (14) 141 (113)
151- 160 0(0) 29 (23) 44(35) 35 (28) 35 (28) 26 (20) 168 (134)
161 - 170 0 (0) 34 (27) 53(42) 42 (33) 42 (33) 31 (25) 201 (161)
171 - 180 32 (25) 32 (25) 48 (39) 38 (31) 38 (31) 28 (23) 216 (173)
181 - 190 31 (25) 41 (32) 54 (43) 37 (30) 37 (30) 37 (30) 237 (190)
191 - 200 30 (24) 53 (43) 53 (43) 37 (30) 37 (30) 37 (30) 27 (22) 275 (220)
201 - 210 31 (25) 54 (43) 54 (43) 56 (45) 37 (30) 37 (30) 37 (30) 306 (245)
≥ 210 32 (25) 49 (39) 55 (44) 38 (31) 38 (31) 38 (31) 28 (23) 279 (223)

Rates shown above refer to recommended application of available fertiliser. Chemical fertiliser rates should be calculated by deducting the available N contained in organic fertiliser applications from the rates shown in the table above.
Stocking rate is calculated as the total annual nitrogen (kg) excreted by grazing livestock averaged over the net grassland area (grazing and silage area). Stocking rate refers to grassland area only.
Rates shown above refer to grazed swards only, and are not suitable as a guideline value of the N requirement for the entire grassland area. The N requirement for the entire grassland area will depend on the proportions of the area that are grazed, or cut as silage or hay. Lower rates of N should be used where clover is present in the sward. A good clover sward will reduce N requirements.
Only fertilize to the stock-carrying capacity of the soil. This often varies with in the farm.
Chemical or organic fertilisers cannot be applied during periods when application is prohibited by nitrates regulations.
At stocking rates above 210 kg/ha N, N advice is constrained by nitrates regulations.

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 fertiliser use to stocking density on the farm at different times of the year avoids excessive use.
  • Applying nitrogen fertiliser ‘little and often’ during the growing season gives most efficient response in terms of grass growth.

P for cattle grazed swards**

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).

Grazed Swards
Soil P IndexFarm Stocking Rate (kg/ha Org N)
< 130131 -170171- 210>210
1 27 30 33 36
2 17 20 23 26
3 7 10 13 16
4 0 0 0 0
(kg/ha * 0.8 =units/ac)

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.

K for cattle grazed swards**

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

Grazed Swards
Soil K Index Stocking Rate (kg/ha Org N)
< 130131 -170171- 210>210
1 70 75 80 85
2 40 45 50 55
3 10 15 20 25
4 0 0 0 0
(kg/ha * 0.8 =units/ac)

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

 

*Deductions for P depending on concentrate feeding  

Concentrate
(t/ha)
Amount of P in concentrates fed to livestock
(This must be deducted from fertiliser P above)
0.5 2.5 (2) 2.5 (2) 2.5 (2) 2.5 (2)
1.0 5 (4) 5 (4) 5 (4) 5 (4)
2.0 10 (8) 10 (8) 10 (8) 10 (8)

 

Suggested Fertiliser (N, P & K) Programmes

N, P & K Recommendation’s for beef grazing stocked at 131 to 170kg Org N/ha
N Advice kg/haSoil P & K IndexP
kg/ha
K
K/ha
Fertiliser Programme
(bags/ac)
201
(161 units/ac)


(  )= units/ac
1 30 (24) 75 (60) 2.4 bags x 10-10-20
5.0 bags CAN
2 20 (16) 45 (36) 1.6 bags 10-10-20
5.3 bags CAN
3 10 (8) 15 (12) 3 bags 27-2.5-5.0
2.95 bags CAN
4 0 0 5.95 bags CAN

 

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 fertilisers that contain S.