Nitrogen

Continuous tillage: - crops that follow short leys (1-5 years) or tillage crops

Nitrogen Index System

See the legislation here  SI No.  393 2022

Tillage crops that follow permanent pasture (5 years or more)

Nitrogen index 

See the legislation hereSI No.  393 of 2022

Maximum fertilisation rates of nitrogen on tillage crops

• ¹ Where proof of higher yields is available, an additional 20kg N/ha may be applied for each additional tonne above the following yields;
  • Winter Wheat - 9.0 tonnes/ha Spring Wheat - 7.5 tonnes/ha
  • Winter Barley - 8.5 tonnes/ha Spring Barley - 6.5 tonnes/ha
  • Winter Oats – 7.5 tonnes/ha Spring Oats – 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.

• ² Where milling wheat is grown under a contract to a purchaser of milling wheat an extra 30 kg N/ha may be applied

  ³ Where malting barley is grown under a contract to a purchaser of malting barley, an extra 20 kg N/ha maybe applied where it is shown on the basis of agronomic advice that additional nitrogen is needed to address a proven low protein content in the grain

  ⁴ Length of growing season

• Table 16- SI No.  393 of 2022

Phosphorus

(See here for extracts from the Teagasc Green Book of Major and Minor Nutrient Advice for productive agricultural crops ) 

Phosphorus index system

Phosphorus index system (Table 11- SI No.  393 of 2022)

P & K off takes in cereal crops (kg/ha) per tonne of grain yield

Example- A 10 ton/ha crop of Wheat with the straw chopped removes 38kg/ha P and 98 kg/ha K  

Maximum Phosphorus rates on tillage crops

¹ The fertilisation rates for soils which have more than 20% organic matter shall not exceed the amounts permitted for Index 3 soils.

² 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 (for Cereals only). The higher yields shall be based on the best yield achieved in any of the three previous harvests, at 20% moisture content.

³ Where pH is greater than or equal to 7, 20kg P/ha may be applied on soils at phosphorus index 4

⁴ Must be incorporated prior to or during sowing.

⁵ For winter cereals on soils of P index 1 and 2, 20 kg of the maximum P fertilisation rate may be applied up to 31st October, which must be incorporated prior to or during sowing

⁶ Potatoes - Where soil P levels above 15ppm no P fertiliser required.

Timing of P application

At soil P index 1 it is advisable that P be incorporated at or before sowing. At soil P indices 2-3, P can be incorporated prior to sowing. Restricted periods for fertiliser application as set out in SI 393 of 2022  must be respected.