Joe Sheehy: Reseeding key to reaching 2020 growth targets
Farmers now realise the value of reseeding, but the amount of ground reseeded any year largely depends on the weather and the financial position on farms.
With the demand for more grass in future it is likely that the there will be a big increase in reseeding, because together with lime and fertiliser it gives the fastest return on investments to farmers.
The price of seed mixes are down this spring and are generally costing about €60 for a 12kg pack (1 acre).
Widespread Teagasc surveys indicate that many Irish pastures are producing 50% less than their potential. Based on Moorepark studies, there is huge variation in grass dry matter production on farms. There is up to 50% difference between farms and 60% within farms and the key factor is the level of perennial ryegrass within pastures.
Of course poor soil fertility, soil type, and poor management will also significantly reduce grass production, as well as utilisation. Over 80% of soil samples are deficient in P, K or lime.
Not only will pastures with low ryegrass content produce poorly, but will be 25% less responsive to nutrients.
Note that low lime status will severely reduce the response to fertilisers.
The majority of the differences in production between pastures are in the early part of the year up to May.
Reseeding pastures with a low level of perennial ryegrass has become more important than ever. With the end of quotas, farmers will require more feed. They cannot afford to be buying unnecessary large amounts of concentrates to supplement poor grass and silage or to be applying fertiliser on poor pastures that give a poor response.
The target for most dairy farmers in future will be 2.5 cows per ha (1 cow/ac). For efficient milk production, this requires grass production of around 14 tonnes D.M. per ha, which is 40% higher than the average production on Irish dairy farms at present.
Potential 35% increase in yields of grass and silage (depending on how bad the old pasture is and how good the reseeding is carried out + adequate lime and fertiliser).
Better response to fertilizers (25% better response to N)
20% higher digestibility
Better seasonal growth
Better quality silage easier to preserve; +10 units DMD
Big savings in concentrate requirements; 60 cent per animal per day
Better animal performance; higher milk yields (5L/cow/day), higher milk protein (+0.2%) and live weight gain.
Excluding the costs of fertiliser and lime (common to old and new pastures) the extra costs associated with reseeding, varies from €200 to €250 per acre.
The extra grass output should be up to 1.5 tonne of dry matter (7.5 t. grass) per acre, per year, which is worth €200 per tonne. In addition, the reseeded pasture is much higher quality and grows earlier in the year.
Assuming that you maintain the reseeded pasture in a highly productive state for 8 to 10 years, reseeding is the best investment a farmer can make.
If on the other hand you allow reseeds to revert back to poor weedy pastures in a few years, reseeding is not worthwhile. Thus, the job should be done right, with proper follow up, or not done at all.
In order to justify the cost of reseeding many different factors should be considered. The botanical composition of the existing swards and the management of the grassland after reseeding should be the main influencing factors. The demand for extra feed on your farm is another factor to consider.
