Do: Use the PPI
The pasture profit index (PPI) has been developed by researchers in Teagasc Moorepark since 2012. The purpose is to rank grass varieties on economically important traits for Irish farmers. The traits are yield (spring, summer and autumn), silage and persistency. Each of the traits has an economic value. For example, spring growth is much more valuable than summer growth because extra grass in spring can displace expensive concentrates and silage. The values for each trait are added together and ranked. See Table 1 for the current PPI list.
Do: select varieties from the recommended lists
Only varieties on the recommended lists have a PPI, so by choosing a variety from the PPI you are ensuring that you are getting a variety as recommended by the Department of Agriculture with information about its characteristics. Not all varieties for sale are on the recommended lists so, in these cases, the information on the variety is limited.
While these seeds might come at a discount, it is a risky investment as you don’t know how they will perform under Irish conditions. The recommended lists for Northern Ireland has similar protocols to the Irish recommended list.
Don’t: be afraid to use monocultures
The use of monocultures (only one variety) has increased in Ireland in recent years. Part of the reason for this has been the on-farm monoculture trial being run by Moorepark in conjunction with the PPI. See Table 2 for a breakdown of how each variety has performed on 80 Irish commercial farms over the years from 2013 to 2015.
The variety with the highest yield was Abergain, with an average of 13.3t/ha, while Majestic grew the least with an average of 12t/ha. I would not have any problem with using monocultures provided that there is accurate information available on the variety and it is performing well for each trait.
Don’t: focus too much
on silage
In the past, varieties were picked based on their yield of silage but with extended grazing, this has become less important.
Of much more importance is spring and autumn growth and quality. The difference in quality between the varieties on the PPI is far greater than the difference between the varieties on silage yield.
Most silage fields are grazed at least four times a year and as much, if not more, of the grass they grow is used for grazing stock, so the growth and quality characteristics are important.
Do: focus on spring and autumn growth
Spring growth is a very important trait in a grass variety. When we think about it, every extra kilo of grass utilised in spring displaces a kilo of meal or a kilo of silage in the diet. For grass to be utilised in spring, it must be either grown in the spring or carried over from the previous autumn. Improving spring and autumn growth will allow for cheaper feed costs and the potential to increase stocking rates.
Don’t: settle for a bad variety in a mix
A grass seed mix is only as good as the sum of its parts. Some grass seed mixtures will have varieties of varying qualities in them. In many cases, they will be promoted as being top varieties and while they may have some good varieties in the mix, there may be inferior or filler varieties included too. These will bring down the quality of the resultant sward. So, when looking at a mix, make sure it only has good varieties that are up near the top of the PPI.
Don’t: focus too much on ground cover
In the PPI, persistency is measured by the change in ground score over time. Ground-scoring is a visual assessment of the degree of ground cover or sward density at the end of a season. While varieties with a high ground score are desirable when trying to prevent poaching, the research would say that, at present, varieties with a high ground score tend to have poorer quality characteristics and cows don’t graze them out as well.
Do: include tetraploid varieties
Tetraploids, by their nature, are more open than diploid varieties and have a more erect growth pattern. Most of the research work would show that they have higher yield and better quality characteristics than diploids. The problem is their openness. For this reason, many farmers on heavy land don’t use tetraploid varieties in their grass seed mixtures.
While this makes sense if the sole objective is to prevent poaching, it has a negative effect on grass production and quality if the whole farm is in diploids. The best policy is to include some tetraploid varieties. Use low rates on heavy land; 20% to 30%. Higher inclusion rates can be used on drier land.
Do: include clover
Based on the research work at Clonakilty, the lost production from not having clover in more Irish swards is phenomenal. An extra 1.5t/ha of pasture growth and an extra 55kg of milk solids per cow on the grass and clover swards are the standout figures from the trial.
When faced with these statistics, the reasons for not sowing clover when reseeding don’t hold water. We have a bit to learn and it might not last long, but anything that improves grass growth and milk solids output, with minimal input albeit a bit more management, needs to be seriously looked at.
Read more
Focus: Reseeding and feed options
Do: Use the PPI
The pasture profit index (PPI) has been developed by researchers in Teagasc Moorepark since 2012. The purpose is to rank grass varieties on economically important traits for Irish farmers. The traits are yield (spring, summer and autumn), silage and persistency. Each of the traits has an economic value. For example, spring growth is much more valuable than summer growth because extra grass in spring can displace expensive concentrates and silage. The values for each trait are added together and ranked. See Table 1 for the current PPI list.
Do: select varieties from the recommended lists
Only varieties on the recommended lists have a PPI, so by choosing a variety from the PPI you are ensuring that you are getting a variety as recommended by the Department of Agriculture with information about its characteristics. Not all varieties for sale are on the recommended lists so, in these cases, the information on the variety is limited.
While these seeds might come at a discount, it is a risky investment as you don’t know how they will perform under Irish conditions. The recommended lists for Northern Ireland has similar protocols to the Irish recommended list.
Don’t: be afraid to use monocultures
The use of monocultures (only one variety) has increased in Ireland in recent years. Part of the reason for this has been the on-farm monoculture trial being run by Moorepark in conjunction with the PPI. See Table 2 for a breakdown of how each variety has performed on 80 Irish commercial farms over the years from 2013 to 2015.
The variety with the highest yield was Abergain, with an average of 13.3t/ha, while Majestic grew the least with an average of 12t/ha. I would not have any problem with using monocultures provided that there is accurate information available on the variety and it is performing well for each trait.
Don’t: focus too much
on silage
In the past, varieties were picked based on their yield of silage but with extended grazing, this has become less important.
Of much more importance is spring and autumn growth and quality. The difference in quality between the varieties on the PPI is far greater than the difference between the varieties on silage yield.
Most silage fields are grazed at least four times a year and as much, if not more, of the grass they grow is used for grazing stock, so the growth and quality characteristics are important.
Do: focus on spring and autumn growth
Spring growth is a very important trait in a grass variety. When we think about it, every extra kilo of grass utilised in spring displaces a kilo of meal or a kilo of silage in the diet. For grass to be utilised in spring, it must be either grown in the spring or carried over from the previous autumn. Improving spring and autumn growth will allow for cheaper feed costs and the potential to increase stocking rates.
Don’t: settle for a bad variety in a mix
A grass seed mix is only as good as the sum of its parts. Some grass seed mixtures will have varieties of varying qualities in them. In many cases, they will be promoted as being top varieties and while they may have some good varieties in the mix, there may be inferior or filler varieties included too. These will bring down the quality of the resultant sward. So, when looking at a mix, make sure it only has good varieties that are up near the top of the PPI.
Don’t: focus too much on ground cover
In the PPI, persistency is measured by the change in ground score over time. Ground-scoring is a visual assessment of the degree of ground cover or sward density at the end of a season. While varieties with a high ground score are desirable when trying to prevent poaching, the research would say that, at present, varieties with a high ground score tend to have poorer quality characteristics and cows don’t graze them out as well.
Do: include tetraploid varieties
Tetraploids, by their nature, are more open than diploid varieties and have a more erect growth pattern. Most of the research work would show that they have higher yield and better quality characteristics than diploids. The problem is their openness. For this reason, many farmers on heavy land don’t use tetraploid varieties in their grass seed mixtures.
While this makes sense if the sole objective is to prevent poaching, it has a negative effect on grass production and quality if the whole farm is in diploids. The best policy is to include some tetraploid varieties. Use low rates on heavy land; 20% to 30%. Higher inclusion rates can be used on drier land.
Do: include clover
Based on the research work at Clonakilty, the lost production from not having clover in more Irish swards is phenomenal. An extra 1.5t/ha of pasture growth and an extra 55kg of milk solids per cow on the grass and clover swards are the standout figures from the trial.
When faced with these statistics, the reasons for not sowing clover when reseeding don’t hold water. We have a bit to learn and it might not last long, but anything that improves grass growth and milk solids output, with minimal input albeit a bit more management, needs to be seriously looked at.
Read more
Focus: Reseeding and feed options
SHARING OPTIONS