Recent research by Teagasc has set about investigating the key management practices necessary to optimise the amount of grass grown on Irish farms. However, before outlining these practices, it is first necessary to establish just how important grass is to the profitability of Irish beef production.
Grass is the key
It is widely known that the ability to grow and utilise high quantities of grazed grass is what gives Irish beef systems a competitive advantage over its EU counterparts. To put a figure on it, the cost of producing 1kg of liveweight (LW) in Ireland from grass is 80-85% less, on average, than that from an intensive, concentrate-based system used in other countries.
What is more surprising, however, is the failure of so many Irish beef farmers to take advantage of this. Research shows that many Irish farms are only producing 50% of their grass growth capability, while stocking rates on Irish beef farms are also very low – at an average 1.2 LU/ha. Furthermore, while progressive beef farmers are striving to grow 10t DM/ha/year, the reality is that average beef farms are only growing between 4.7t to 7.8t DM/ha/year.
It is on these under-growing farms where the most potential lies – if the right grassland management practices are put in place. To guide that, Teagasc has outlined management practices in in three key areas: soil fertility, grassland management and the role of white clover to increase grass growth and utilisation on Irish farms. While grazing management is so often discussed when targeting higher grass production, this article will focus on the two lesser-mentioned elements of soil fertility and white clover.
Soil fertility
Soil fertility could be considered as the fuel to the grass-growing engine. The three key requirements when it comes to soil fertility are phosphorous (P), potassium (K) and soil pH (lime). The first step to correcting soil fertility should be to focus on soil pH.
Soil pH affects the availability and uptake of both major and trace elements by crops. The ideal pH for grass growth, N release and P and K availability is 6.3. Research has indicated that 5t/ha of lime applied to a soil with low pH (5.3) increased grass production by a total of approximately 1.5t DM/ha in the following two years. Other research has shown that on a soil with low pH (5.3) and old permanent pasture, the application of 7.5t of lime/ha increased the stock-carrying capacity by 20% by the end of the first year and by 100% in the fourth year.
In comparison with fertiliser, lime application in that trial was estimated to be equivalent to using 60 units/ac of N fertiliser per year.
When soil pH is corrected, it is then time to turn towards P and K. The target soil index for P is Index 3 (5.1–8.1 mg/l) and for K is Index 3 (101–150 mg/l). To increase soil fertility status, the required amount of P and K is 50kg P/ha and 2 to 5kg K/ha for a 1 mg/L soil test change, respectively.
Organic manure can play a big part in building soil P and K. The fertiliser value of cattle slurry is equivalent to approximately 6.3kg/ha (five units/acre) of P and 37.5kg/ha (30 units/acre) of K per 1,000 gallons. Again, recent research has shown that the benefits of optimising soil P and K. Soils with P Index 3 will grow approximately 1.5 t DM/ha/year more grass than soils with P Index 1.
With all of this in mind, it is startling to think that approximately 90% of the soil samples taken from Irish farms are limiting in one of these three major soil nutrients.
Using white clover
A number of experiments undertaken at Teagasc have shown the benefit of white clover inclusion in grassland in terms of savings in N fertiliser and increased animal performance. This is becoming even more significant as the cost of chemical N continues to rise. Previous research has shown that clover can contribute up to 100kg N/ha/year through N fixation, resulting in a significant saving for farmers.
Clover, however, also has the ability to positively impact upon animal performance in comparison with grass-only swards, particularly in the second half of the year when sward clover content is at its greatest. When included in grass swards, it has been shown to increase overall annual herbage production by between 900kg and 1,500kg DM/ha.
In conclusion
The research concludes that all farms can grow more grass through improved grassland management, most importantly, regardless of location. Furthermore, the farms that are currently undertaking the optimum grass growing practices are in turn more likely to improve grass production and increase farm profit irrespective of beef price.
This research was carried out by Teagasc researchers Michael Egan and Karen Dukelow.
Read more
Beef management: dealing with heavy growth and managing the autumn herd
Grass + beef: get measuring for the autumn run-in
Tullamore Farm: back to work after a day of farm walks
Recent research by Teagasc has set about investigating the key management practices necessary to optimise the amount of grass grown on Irish farms. However, before outlining these practices, it is first necessary to establish just how important grass is to the profitability of Irish beef production.
Grass is the key
It is widely known that the ability to grow and utilise high quantities of grazed grass is what gives Irish beef systems a competitive advantage over its EU counterparts. To put a figure on it, the cost of producing 1kg of liveweight (LW) in Ireland from grass is 80-85% less, on average, than that from an intensive, concentrate-based system used in other countries.
What is more surprising, however, is the failure of so many Irish beef farmers to take advantage of this. Research shows that many Irish farms are only producing 50% of their grass growth capability, while stocking rates on Irish beef farms are also very low – at an average 1.2 LU/ha. Furthermore, while progressive beef farmers are striving to grow 10t DM/ha/year, the reality is that average beef farms are only growing between 4.7t to 7.8t DM/ha/year.
It is on these under-growing farms where the most potential lies – if the right grassland management practices are put in place. To guide that, Teagasc has outlined management practices in in three key areas: soil fertility, grassland management and the role of white clover to increase grass growth and utilisation on Irish farms. While grazing management is so often discussed when targeting higher grass production, this article will focus on the two lesser-mentioned elements of soil fertility and white clover.
Soil fertility
Soil fertility could be considered as the fuel to the grass-growing engine. The three key requirements when it comes to soil fertility are phosphorous (P), potassium (K) and soil pH (lime). The first step to correcting soil fertility should be to focus on soil pH.
Soil pH affects the availability and uptake of both major and trace elements by crops. The ideal pH for grass growth, N release and P and K availability is 6.3. Research has indicated that 5t/ha of lime applied to a soil with low pH (5.3) increased grass production by a total of approximately 1.5t DM/ha in the following two years. Other research has shown that on a soil with low pH (5.3) and old permanent pasture, the application of 7.5t of lime/ha increased the stock-carrying capacity by 20% by the end of the first year and by 100% in the fourth year.
In comparison with fertiliser, lime application in that trial was estimated to be equivalent to using 60 units/ac of N fertiliser per year.
When soil pH is corrected, it is then time to turn towards P and K. The target soil index for P is Index 3 (5.1–8.1 mg/l) and for K is Index 3 (101–150 mg/l). To increase soil fertility status, the required amount of P and K is 50kg P/ha and 2 to 5kg K/ha for a 1 mg/L soil test change, respectively.
Organic manure can play a big part in building soil P and K. The fertiliser value of cattle slurry is equivalent to approximately 6.3kg/ha (five units/acre) of P and 37.5kg/ha (30 units/acre) of K per 1,000 gallons. Again, recent research has shown that the benefits of optimising soil P and K. Soils with P Index 3 will grow approximately 1.5 t DM/ha/year more grass than soils with P Index 1.
With all of this in mind, it is startling to think that approximately 90% of the soil samples taken from Irish farms are limiting in one of these three major soil nutrients.
Using white clover
A number of experiments undertaken at Teagasc have shown the benefit of white clover inclusion in grassland in terms of savings in N fertiliser and increased animal performance. This is becoming even more significant as the cost of chemical N continues to rise. Previous research has shown that clover can contribute up to 100kg N/ha/year through N fixation, resulting in a significant saving for farmers.
Clover, however, also has the ability to positively impact upon animal performance in comparison with grass-only swards, particularly in the second half of the year when sward clover content is at its greatest. When included in grass swards, it has been shown to increase overall annual herbage production by between 900kg and 1,500kg DM/ha.
In conclusion
The research concludes that all farms can grow more grass through improved grassland management, most importantly, regardless of location. Furthermore, the farms that are currently undertaking the optimum grass growing practices are in turn more likely to improve grass production and increase farm profit irrespective of beef price.
This research was carried out by Teagasc researchers Michael Egan and Karen Dukelow.
Read more
Beef management: dealing with heavy growth and managing the autumn herd
Grass + beef: get measuring for the autumn run-in
Tullamore Farm: back to work after a day of farm walks
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