Increasing grassland productivity has never been more important according to Dr. Michael O’Donovan, Head of Grassland Science, at Teagasc, Moorepark.
Farmers are constantly faced with investment decisions, some might be worthwhile, while many are wasteful. With tightening margins, those investment choices will become more difficult, due to tighter cash flow. According to Michael, a clear route to getting a payback on investment is to focus on your swards.
Michael has being involved in the development of PastureBase Ireland, since its conception in 2012. The most recent dry matter production figures from PastureBase Ireland demonstrate that the higher producing grassland farms can grow between 15.5 and 16.5 t grass DM/ha and support stocking rates >3 cows/ha. The key aspect for grassland is to be able to quantify a farms performance and benchmark it annually. Achieving this level of performance requires skilled grassland management and the effective use of grass measurement tools at farm level.
''Grassland Management without measurement is very difficult''
Grass measurement is one of the most important skills any farmer with a grazing system should develop. Walking the farm weekly and creating the grass wedge will allow a farmer to plan ahead and manage surpluses/deficits before they occur, meaning a more proactive approach to grassland management can be adapted. This will have a positive effect on animal performance and profitability. In addition, measuring grass growth across a full year allows the farmer to assess the performance of individual paddocks and if some paddocks are underperforming they should be targeted for reseeding.
Figure 1. Surplus Grass Wedge
It is evident from this wedge that the farm has surplus grass. Pre-grazing yields are too high and above target as are residuals. Decisions need to be made to rectify the problem.
The investment in reseeding is expensive, it is crucial that the right paddocks are identified for reseeding. The job must also be completed correctly to ensure the newly established swards have the capability to produce grass as the farm demands it. Reseeding alone will not solve all the issues of grass growth on the farm, according to Michael. “It must be combined with good grazing management, grass measurement and a targeted soil fertility program. These three management practices working in unison will allow the farm to achieve its potential grass production”.
Figure 2. Ideal Grass Wedge
All the paddocks are meeting the green line – there are no surpluses or deficits. Everything is on target. The farm should continue to monitor growth rates.
Reseeding is important as a mechanism to increase the perennial ryegrass content in swards. Soil fertility is critical to maximising the performance and longevity of swards at farm level, with Teagasc recently highlighting that 90% of all soils are sub-optimal in terms of pH, phosphorus (P) or potassium (K). Without doubt, this is costing farms throughout the country significantly in terms of under-performing grass swards and the necessity to bring in more expensive supplements to overcome grass deficits in the system.
Figure 3 presents the total dry matter production in 2013 of 8 varieties sown on commercial dairy farms in a Teagasc trial.
An on-farm trial conducted by Teagasc is ongoing since 2011 whereby grass varieties are being sown on commercial farms and their dry matter performance is being measured. Individual paddocks are being sown with single varieties (monocultures). With every farm involved sowing one common cultivar (Tyrella), which is considered the control. This allows the performance of varieties to be compared across farms. In 2012, there were 8 varieties on-trial, this increased to 14 varieties under trial in 2014. Over 70 farms are involved in this research and these farms are located throughout the country. According to Michael, this work will continue to expand across more farms and encompass more regional variation. “The bigger the range in locations across the country the better the data, as more environmental variation can be accounted for” according to Michael.