Index	Nitrogen (Units/ac)	Phosphorus (Units/ac)	Potassium (Units/ac)	Sulphur (Units/ac)
1	180	44	52	40
2	144	36	28	40
3	128	28	20	40
4	112	0	0	40

1. N rates shown above refer to application rates of available fertilizer. Chemical fertilizer rates should be calculated by deducting the available N contained in organic fertilizer applications from the rates shown in the above table.
2. See accordian below for information on Soil N Index.
3. The Phosphorus fertilization rates for soils which have more than 20% organic matter shall not exceed the amounts permitted for Index 3 soils.
4. P rates shown above refer to recommended application rates of available fertilizer.
5. Chemical fertilizer rates should be calculated by deducting the P contained in organic fertilizer applications from the rates shown in the above table.

Index	Nitrogen (kg/ha)	Phosphorus (kg/ha)	Potassium (kg/ha)	Sulphur (kg/ha)
1	225	55	65	50
2	180	45	35	50
3	160	35	25	50
4	140	0	0	50

1. 1. N rates shown above refer to application rates of available fertilizer. Chemical fertilizer rates should be calculated by deducting the available N contained in organic fertilizer applications from the rates shown in the above table.
   2. See accordian below for information on Soil N Index.
   3. The Phosphorus fertilization rates for soils which have more than 20% organic matter shall not exceed the amounts permitted for Index 3 soils.
   4. P rates shown above refer to recommended application rates of available fertilizer.
   5. Chemical fertilizer rates should be calculated by deducting the P contained in organic fertilizer applications from the rates shown in the above table.

[table “” not found /]

1. Assuming no organic manures are supplied
2. Assuming Nitrogen Index = 1

There is, as yet, no satisfactory Irish laboratory test for N in soils at farm level.

1. Nutrient N advice for grassland systems (grazing and conservation) depends mainly on land use and farming system, and particularly on the stocking rate.
2. For crops requiring cultivation, the available soil N can be deduced from the previous cropping and manurial history, and the type of soil. Thus, N fertilizer advice is determined by the soil N supply status. This depends in turn on the previous cropping history.

The supply status is categorised into an Index system for grass establishment and tillage crops.

N Index for tillage crops that follow short leys or tillage

N Index for pasture establishment or tillage crops that follow long leys or permanent pasture

1. The optimum soil pH for Oilseed Rape is above 6.5.
2. Where lime
   recommendations advise are in excess of 7.5 t/ha, it is good practice to apply the lime over a 3-year period. This helps avoid too much lime applied at any one time which can lead to boron and manganese
   deficiencies.
3. Check out the Fertilizer Association of Ireland technical bulletin for more information on Liming

1. Oil seed rape responds to the application of S on most soils but particularly on those that are
   not frequently receiving organic manures are light or low in organic matter.
2. Application of 20
   to 30 kg/ha S will normally be adequate, with the higher rates being applied on lighter soils.
3. The timing is not critical and Sulphur should be applied with the nitrogen.

1. Oilseed Rape may respond to the application of Magnesium at soil Index 1
2. Goulding Soil Nutrition offer Wolf Trax Magnesium DDP as an option to be coated onto fertilisers, Kieserite, a Mg + S fertiliser and Polysuphate (K, Mg, S, Ca) as options to treat Mg deficiencies. Including Magnesium in your fertilisers allows for earlier intervention (seedbed) when magnesium deficiency is a known issue.
3. Magnesium sulphate (epsom salts) is widely used to correct Mg deficiency and
   comes with the benefit of additional small quantity of S.
4. Find out more about Magnesium

1. Boron should be routinely applied to oil seed rape especially when the soil test is below 1
   mg/l.
2. Severe B deficiency causes stunting and brittle petioles, but relatively mild deficiency results in poor seed set and a reduction in seed numbers per pod and seed weight. These conditions can also be induced by severe summer drought.
3. Normally Boron should be applied to winter oilseed rape at the onset of spring growth either in a
   compound fertilizer or more commonly as a foliar application.
4. In situations where there is a
   high risk of deficiency e.g. low soil B levels, high pH, sandy soil, an autumn application should be applied.
5. For spring oilseed rape an application should be made soon after emergence when there is good crop cover or alternatively it may be applied as a component of a compound fertilizer before sowing.
6. Boron applications should be completed before the onset of flowering.
7. Goulding Soil Nutrition offer Wolf Trax Boron DDP as an option to be coated onto fertilisers. Coating fertilisers with Boron allows for earlier intervention (seedbed) when Boron deficiency is a known issue.
8. Find out more about Boron.