Ireland in 2015 will produce milk without the restriction of milk quota. But the future of an efficient low-cost milk production system will depend on low cost feed in the form of grazed grass being converted to milk.
On many farms the level of grass production is too low. PastureBaseIreland (PBI) was launched in January 2013 with the aim of building a large national grassland database to encourage increased grass utilisation and production at farm level.
The average dry matter (DM) production in 2013 was 12.5t/ha for farms which had a high level of grass measurement. There was significant variation in the amount of grass produced between farms ranging from 8t/ha to 16t/ha.
There was also significant variation between the average number of grazings per paddock achieved between farms, ranging from four to over nine grazings. This data proves that there is significant potential for farmers to grow more grass on farms.
The question is how, and the answer lies in addressing a series of underlining reasons for poor grass production on individual farms.
Reseeding might be just one of the answers, since soil fertility, soil type and drainage may also be issues that need tackling.
It should also be routine for farmers at the start of every grazing season to target weaker paddocks for reseeding or lime, phosphorus (P) and potassium (K) applications.
Grassland reseeding has the overall aim of replacing a paddock with a new grass sward, ideally with 100pc perennial ryegrass that has a high production capacity. Much of this depends on how the sward is managed, the level of soil fertility management and the grass varieties sown.
Many farmers do not recognise the economic loss of underperforming paddocks. These poor performers are typically allowing farmers to graze stock 4-6 times a year. This costs dairy farmers up to €300/ha in lost grass production during the growing season.
Productive grassland farms must have perennial ryegrass dominated swards. Recent Moorepark research shows that old permanent pasture produces an average of 3tDM/ha/year less than perennial ryegrass dominated swards.
Old permanent pasture is also up to 25pc less responsive to available nutrients such as nitrogen than perennial ryegrass dominated swards.
As a result, reseeding is a highly cost effective investment. Regular reseeding can increase the grass growth capacity of the farm substantially and generate as good or better a return as any other farm investment.
The objectives of reseeding are to create swards that:
1. Increase the overall productivity of the farm through:
* Increasing the carrying capacity (stocking rate);
* Allowing higher animal output – 8pc higher milk output per hectare relative to permanent pasture;
* Increased grass quality;
2. Are more responsive to fertiliser;
3. Increase grass utilisation;
4. Allow white clover/perennial ryegrass pastures to establish.
Soil fertility Index 3 required
Reseeding can improve the productivity of a sward. However, soil fertility must be correct for it to have maximum effect. Adequate soil nutrition is the only way to ensure that perennial ryegrass establishes and persist well after reseeding. Soil testing provides information on the soil fertility status of a field or paddock.
Once soil test results are available, appropriate applications of P, K and lime can be made to ensure adequate soil fertility for perennial ryegrass germination, establishment and production.
Michael O'Donovan is a senior researcher at Teagasc's Animal and Grassland Research and Innovation Centre , Moorepark, Fermoy , Co Cork