Perennial Ryegrasses To Match Seasonal Needs?
NORTHERN IRELAND, UK - Preliminary reports from the seed trade show that there were exceptionally high levels of reseeding all across Northern Ireland, during last autumn and this spring. Clearly the message that the most economic and sustainable way of feeding cattle and sheep is built upon renewing swards to keep grassland in tip-top condition.Grass Farmer Skills
This recent surge in reseeding is evidence of farmers increasing focus on greater dependence of grass to drive herd performance. This has brought more emphasis on grass budgeting and the skills for managing grass covers.
The AFBI/DARD GrassCheck and CloverCheck monitoring services have become important tools to help farmers adjust grazing areas in line with expected grass growth. This helps to match the requirements of the herd for grazed grass without building excessive stands where grass quality quickly declines.
There is irrefutable evidence from AFBI research, CAFRE demonstration work at Greenmount College and on focus farms, that managing sward covers holds a better grass quality throughout the grazing season and makes very substantial contributions to the profit margins of any cattle based enterprise. An implication of this has been that both farmers and DARD’s technology staff have become more aware of the importance of seasonal growth patterns of different perennial ryegrass varieties.
Timing of Production
In the past the DARD Recommended List only reported the total annual yields of perennial ryegrasses for both silage and grazing managements. Beyond the edict of “sow early varieties for early spring growth”, seasonal variation patterns were not seen as important. As the science of herd management at grass has become more sophisticated, particularly with the adoption of techniques from New Zealand, so the clear differences between varieties in their growth rates throughout the season has become more important. Today, the recommended list gives precise detail on the distribution of growth of each variety, both for grazing and silage uses.
It is an unavoidable fact, but when the weather is so poor that grass isn’t growing, then seasonal growth differences between varieties gets wiped aside. While science has not found a solution to that problem, and probably won’t, the Recommended List shows that certain varieties will deliver more yield than others at specific periods of the grazing season.
The attached table on grazing performance shows the seasonal yields of the current diploid ‘Bold Type’ recommended perennial ryegrasses from the intermediate and late maturing groups. There is still evidence of the link between heading date and spring growth as shown by the spring performance of Spelga, the earliest of the ‘Intermediates’, compared to Foxtrot and Pastour, the latest of the ‘Late’ group. Nonetheless, breeders have created varieties with different seasonal growth patterns that are not linked to maturity date.
For example, Denver is relatively dormant in spring and autumn, it is very high performing in early summer. Pastour has a similar growth curve, but less acute differences between the growing periods, and Bree and Gandalf have a more even distribution of growth through the season.
In contrast, AberZest is 14 per cent higher yielding in spring than Denver, despite having the same heading date and also gives its peak performance in the late summer and autumn. AberStar has a similar growth pattern despite being six days earlier maturing. Both these varieties have growth patterns that will help extend the growing season. Foxtrot has an exceptional early summer growth and maintains a good performance through to the end of the season, while AberAvon has a similar pattern but with less extreme differences between summer growth and the spring and autumn periods.
Mixtures in Harmony
An important skill of the seeds merchant is to evaluate all the differing performance factors, such as seasonality, total yield and grass quality to produce a blend of varieties that work in harmony to complement each others strengths. The better the mixture is tailored to the grazing demands of the farm the easier it will be to maintain control of grass covers and hold a good balance between supply and grass quality throughout the season.
So it is very important to have a clear view of when grass supply and herd demand are most likely to be out of step on your farm. Is spring growth crucial? Is extending the growing season an efficiency objective for the new sward? Does your land easily become drought stressed if there are dry summers?
Will your ground be too slow to warm in spring or too quick to get wet and cold in autumn to justify varieties with big out-of-season growth curves? Answers to these types of questions will help your merchant identify which mixture they have designed to meet the type of growth pattern you have described.
The key message from grazing research and advisory demonstrations of herd management at grass, such as from CAFRE, is that control of grass quality and supply is the key to profitable grassland farming. This requires much more skill on the part of the farmer than in former times, but is essential given current financial constraints. The techniques are well established and expert guidance is available from CAFRE and the GrassCheck and CloverCheck services.
The final piece in the system is to have a management plan for regularly replacing mediocre pastures. Making use of the latest breeding advances creates swards capable of delivering a pattern of performance that reduces the need to force growth with more high cost fertilisers and minimises the use of bought-in feed. The better the mixture is tailored to the grazing demands of the farm the easier it will be to maintain control of grass covers and hold a good balance between supply and grass quality throughout the season.
As grazed grass remains the cheapest form of animal feed, the DARD recommended list is a valuable information source to help you and your merchant find those grasses that can best match herd requirements through the season, and minimise costly inputs of fertiliser and feed. Copies of the new 2010 Recommended List of grasses and clovers are available from all DARD county offices or online from www.afbini.gov.uk/reclists.
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