Spring Fertiliser on sheep farms
All going to plan ewes can be turned out to grass as they lamb with minimal supplementary feeding, if any, required post turn-out. From a management, cost and labour point of view, this must be the aim. An early application of Nitrogen is important, as Philip Creighton Teagasc Researcher outlines
Having started your grazing plan for the year the previous autumn all going according to plan ewes can be turned out to grass as they lamb with minimal supplementary feeding, if any, required post turn-out. From a management, cost and labour point of view, this must be the aim. An early application of Nitrogen is an important step to boost and maintain grass supply during early lactation for ewes with an increasing feed demand. Unfortunately, so far this spring weather conditions have not been suitable to apply nitrogen due to low soil temperatures and heavy rainfall. Incorrect application of early Nitrogen (N) is wasteful, costly, pollutes water and increases greenhouse emissions.
Advice at present would be to have plans in place so that once conditions are suitable fertiliser can be spread. This means having fertiliser purchased and in the yard or your contractor booked if bulk spreading. Suitable conditions and considerations to take into account when planning an application of early Nitrogen to grassland swards include:
What is the soil temperature?
Minimum 6OC and rising is required for growth
Are ground conditions suitable?
- Do not spread on wet soils – Possible N Loss and soil damage. Also ensure at least 48 hours without heavy rainfall is forecast after application
Is Grass actively growing?
- Fields with a high perennial ryegrass content and fields with a cover of grass of greater than 400kgDM/Ha (5cm) should be targeted. Fields with lower grass covers should be targeted for slurry or FYM application where available
How much to apply?
- Do not apply more than 30kg N/ha (24 units/ac) in one application. Amount required will depend on feed demand. Typical requirements for sheep farms will range from 20 kg N/ha (17units/ac) for farms stocked at less than 10 ewes/ha up to around 30kg N /ha for farms stocked at 12 ewes/ha or more.
It is worth bearing in mind that response to applied Nitrogen is also dependant on overall soil fertility. If you have not carried out a soil test recently now is the perfect time to do so before you apply any fertiliser or manures. The results can be used to produce a nutrient management plan appropriate to your farm. Fertiliser can account for up to one fifth of the total variable costs on sheep farms so effective management of this commodity has potential to save money. A liming programme should be in place on all farms in order to have soil pH at its optimum year on year. This will prevent soil pH from dropping to such an extent that the release of nutrients and the response to applied fertiliser will be compromised.
For more information on Soil fertility, Grassland Management & Research for Sheep click here