The recommendations in this section are using the RoI fertiliser classification system and are based on Teagasc research.
Due to slight differences between the RoI and NI classification systems, these recommendations are only a guide for Northern Ireland farmers. They can be converted between the RoI and NI classification systems using this Conversion Table.
Before choosing your fertiliser products please consult your local advisor to ensure that you do not exceed the limits for your farm as determined by the nitrates directive (SI no 31 of 2014)
| Table 28. Nutrient Requirements (unit/acre) | |||
|---|---|---|---|
| N | P | K | |
| Index 1 | 128 | 36 | 92 |
| Index 2 | 108 | 28 | 80 |
| Index 3 | 80 | 20 | 68 |
| Index 4 | 48 | 0 | 0 |
The nitrogen recommendations in the above Table are for light shallow soils.
- Where straw is not removed, decrease Phosphorus (P) rates by 4 units and Potassium (K) by 45 units.
- These recommendations are based on the maximum nitrogen levels permitted.
- The fertilisation rates for soils which have more than 20% organic matter shall not exceed the amountspermitted for Index 3 soils.
- Where proof of higher yields is available, an additional 20kg N/ha may be applied for each additional tonne above the following yields;
- Winter Barley – 8.5 tonnes/ha
- The higher yields shall be based on the best yield achieved in any of the three previous harvests, at 20% moisture content.
Fertiliser Recommendation
| Table 29. Application rate (bags/acre) | ||||
|---|---|---|---|---|
| K1 | K2 | K3 | K4 | |
| P1 | 3 x (0-10-20) + 2 x (Classic NK) + 3 x CAN |
3½ X (0-10-20) + 1 x (Classic NK) + 4 X CAN |
3½ X (0-10-20) + 4½ X CAN |
1½ X (16% Superphosphate) + 3 x (Classic NP) + 2 x CAN |
| P2 | 3 X (0-7-30) + 1 x (Classic NP) + 3½ X CAN |
2½ X (0-10-20) + 2 X (CLASSIC NK) + 3 x CAN |
2½ X (0-10-20) + 1 X (CLASSIC NK) + 4 X CAN |
1 X (16% Superphosphate) + 3 X (Classic NP) + 2 X CAN |
| P3 | 2½ X (0-7-30) + 1 x (Classic NK) + 4 X CAN |
2 X (0-7-30) + 2 X (24-2.5-10) + 3 x CAN |
2 X (10-10-20) + 2 X (CLASSIC NK) + 3 x CAN |
½ X (16% Superphosphate) + 3 x (Classic NP) + 2 x CAN |
| P4 | 1½ X (Muriate of Potash) + 1 x (Classic NK) + 4 X CAN |
1½ X (Muriate of Potash) + 4½ X CAN |
1 X (Muriate of Potash) + 1 X (CLASSIC NK) + 4 X CAN |
4½ X CAN No P or K required |
Where proof of higher yields is available, an additional 3.8kg P/ha may be applied on soils at phosphorus indices 1, 2, or 3 for each additional tonne above a yield of 6.5 tonnes/ha. The higher yields shall be based on the best yield achieved in any of the three previous harvests, at 20% moisture content.
Top dressing:
- Phosphorus (P) and Potassium (K) In most cases a recommendation has been given for some P and K to be used in the first nitrogen top dressing in the spring. This is done as part of a responsible nutrient management programme. P and K are always beneficial as a top dressing in the spring as it is less susceptible to leeching from an exposed sod. There is ground cover in the plant leaves and a good root structure to efficiently use these nutrients.
- Nitrogen (N) In general the first application should be applied at GS 28-30 and the remainder to be applied at GS 31-32. A third split is rarely required on winter barley.
- Sulphur (S) should be used on crops up to the Teagasc recommended level of 12 units/S/acre.
- Richland: 22.7 – 2.5 – 5 + 3% Sulphur (S) + Copper (Cu), Manganese (Mn), Magnesium (Mg) and Zinc (Zn). The unique blend of N, P, K with Sulphur and vital trace elements make it an excellent option for top dressing winter cereals in the spring.
- Replenish: 18 – 2.5 – 14 + 2% Sulphur (S) + Copper (Cu), Manganese (Mn), Magnesium (Mg) and Zinc (Zn). The unique blend of N, P, K with Sulphur and vital trace elements make it an excellent option for top dressing winter cereals in the spring.
