Winter Oats

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 30. Nutrient Requirements (unit/acre)
Index Nitrogen Phosphorus Potassium
1 very low 116 36 128
2 low 96 28 116
3 medium 68 20 104
4 high 36 0 0
  • Where straw is not removed, decrease Phosphorus (P) rates by 4 units and Potassium (K) by 95 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.
    • Winter Oats – 7.5 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 31. Application rate (bags/acre)
K1 very low K2 low K3 medium K4 high
P1 very low 3 x 0-7-30
2 ½ x 18-6-12
2½ x Sulfa CAN
3 x 0-7-30
2 x 18-6-12
3 x Sulfa CAN
3 x 0-10-20
3 x Classic NK
2 x Sulfa CAN
2 x 16% Superphosphate
4 x Sulfa CAN
P2 low 3 x 0-7-30
1 x 10-10-20
1 x Classic NK
3 x Sulfa CAN
3 x 0-7-30
1 x 10-10-20
4 x Sulfa CAN
3 x 0-7-30
1 x 18-6-12
3 ½ x Sulfa CAN
1 x 16% Superphosphate
2 ½ x Classic NP
1½ X Sulfa CAN
P3 medium 3 x 0-7-30
2 ½ x Classic NK
2½ x Sulfa CAN
3 x 0-7-30
2 x Classic NK
3 x Sulfa CAN
3 x 0-7-30
1 x Classic NK
3 ½ x Sulfa CAN
1 x 16% Superphosphate
1 x Classic Np
3 ½ x Sulfa CAN
P4 high 2 x muriate of Potash
2 x Classic NK
3 x Sulfa CAN
2 x muriate of Potash
1 x Classic NK
3 ½ x Sulfa CAN
2 x muriate of Potash
4¼ x Sulfa CAN
4¼ x Sulfa CAN
No P or K required

*Assuming N Index 1

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) For winter oats the first application will be made around GS 30, the second around GS 31-32. A third application will not be required.
  • 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.