Sustainable Grassland Management

By Tom Murphy, B&T Dairy Adviser, Teagasc Galway/Clare

Under the terms and conditions of the Nitrates Derogation 2020 and 2021, derogation applicants are required to complete mandatory training before the end of 2021.  Three courses of 5 hours duration each, on water quality & greenhouse gasses, nutrient use efficiency and sustainable grassland management are detailed. 

Research has shown that good grassland management and the grazing of high quality grass substantially reduces the emission of the harmful gasses of methane, nitrous oxide, carbon dioxide and ammonia.

The Grassland Management Course- “Sustainable grassland management practices to improve nutrient use efficiency”, will cover the following core related areas.

• Understanding grass growth rates and demand including appropriate stocking rates.
• Why we need excellent grass quality?
• Rotation Planning - Spring rotation planner, summer wedge and autumn planner.
• Grass Measuring, and understanding the figures.
• Decisions using appropriate software technology.
• Techniques to increase nutrient use efficiency using clover.
• DAFM recommended grass & herbage varieties

It is very easy to get so busy with our farming practices, that we take the benefits of having high quality grass for granted and let standards slip. Well managed, high quality grass is beneficial to

• The Animal,
• The Sward,
• The Environment, and
• The Farmer

Animals grazing grass or fed conserved forage from grass achieve significantly higher intakes when the quality is good, leading to very contented animals. This in turn is converted into higher milk solids production from lactating animals. The milk in turn will have higher constituents.  Typically milk protein difference between grazing grass at the correct stage, is of the order of 0.1% to 0.2% higher, than if left to grow for a further 5 days.  At today’s milk prices, this difference can cost up to 1.5cent per litre. Also, the energy level drop/difference of the forage is typically 1 UFL /animal/day. Young animals on the farm grow at a faster rate, and significantly higher live weight gain is achieved on all animals. Overall animals on the farm are healthier, and performance is maximised, when grassland management is improved.

With better grassland management, a positive momentum is created. The challenge is to graze each sward when it is at/closest to the correct stage for grazing (for the stocking rate of the farm and the time of year). Grazing swards at higher than this, can create a repetition of similar cycles, and the negative consequences are extrapolated. Paddocks that are grazed too soon lead to a reduction in overall growth, as the sward becomes exhausted. In a typical 3 week cycle, 50% of the yield is grown in the 3^rd week (grass grows grass). When grazed at the correct stage, paddocks are grazed off (cleaned-out) better, which leads to increase tillering, better regrowth’s, less weeds, more leaf material and less stem.  Higher animal intakes, in turn, help in keeping the post grazing height correct and consistent. When the grazing rotation is managed well, quicker regrowth’s result. Persistency in the sward improves and the output and response to fertilisers (bagged/slurry/dung) also jumps ahead.  Shorter rotations with dense swards, leads to more grazing’s per paddock. The higher growth rate and quality leads to an additional increase in grass utilised. Research has shown the benefit of this to be about 1.5t grass Dry Matter for an extra grazing rotation. If you are a beef farmer this benefit is worth €100/ha and if you are a Dairy farmer it’s worth €175/ha.

Importantly, the Environment benefits substantially, when a high level of grassland management is adopted.  Less grass and forage is wasted as utilization rates increase. The very high fibre grass and forage materials fed to ruminants leads to significantly more methane gas production, than if fed at the recommended grazing/harvesting stage. Grazing animals redistribute/recycle their own wastes, leading to less slurry production and less ammonia gasses produced. Grazing grass at the correct stage or cover (1400kg DM/ha), instead of allowing 5 or more extra days growth (2000kg DM/ha), results in a 15% reduction of Greenhouse Gas production. Higher quality and higher intakes of grass and forage, leads to a reduced need for imported concentrate feed per unit of production. Better growth rates lead to increased fertiliser uptake, and more efficiency from fertiliser use, which in turn leads to reduced risk of loss to watercourses and air. Nutrients are recycled better, also. Longer days at grass, and extended grazing result in shorter housing and winter feeding periods. This has the knock-on effect of less tractor & machinery work for conservation and feeding of silage and slurry spreading.  It is shown that well managed grass swards act as a sink or store for Carbon and are an important source for Carbon sequestration.  

Where does the farmer fit into this equation? It’s worth stating again, that an extra grass rotation in the year (difference between a farmer with a plan and one who hasn’t) will lead to an extra 1.5t of grass utilized per ha, and this will result in an additional profit of €100 to €175 per ha depending on the system. The calculated benefits of grazing grass instead of feeding silage in spring alone is worth €2.70 per Dairy cow per day and €2 per Beef LU per day.  A well-managed grazing system results in less topping. Where the focus is on grazing, less silage is needed and there is less slurry to be applied. With better quality grass and silage and consistent management, meal feeding can be reduced, without reducing animal performance. Overall, there is less work, less cost and a higher profit. More importantly, this gives an opportunity for an improvement in work-life balance, lifestyle and enjoyment of farming.

Teagasc in the Galway/Clare Region will send its Derogation clients notice when this course is organised in the coming weeks. This is an ideal opportunity to improve your knowledge of grassland management and bring renewed benefit back to your grassland farming enterprise.