Five Grassland Pointers to Minimise The Effect of 2018’s Late Spring
Stick to your timings for cutting silage, use first cut for quality and invest wisely in aftercut nutrition to boost yield from subsequent cuts, advises James Holloway of CF Fertilisers.
1. Don’t delay taking your first cut
With the late Spring and poor early grass growth it’s tempting to consider delaying first cut until there’s more bulk available, but for most dairy and livestock producers this is a false economy.
Grass maturity depends on day length not weather so it will only be delayed by around five days at most and whilst holding off cutting might increase bulk, it will drastically reduce quality.
You’ll then be chasing yield and quality throughout the cutting season with the real possibility of achieving neither and being forced to buy in feeds through the winter to make up the shortfall.
In fact, trials carried out by the SRUC in 2017 showed that whilst delaying first cut by 14 days increased dry matter yield by 1.0t DM/ha, it reduced ME from 10.30 to 8.40 MJ ME/kg DM with the net result of energy harvested falling by nearly 8%.
Over 40 ha of 1st cut grass and with a milk price of 28ppl, this represents around £8100 of lost milk production energy with a corresponding need to buy in feed to make up the energy deficiency.
2. Keep optimising yield and quality in subsequent cuts
If you focus on getting high quality from your first cut you can then use subsequent cuts to build silage stocks. But keep focused on quality – if you need more bulk, take more cuts.
Use ammonium nitrate based compounds with Sulphur, such as SingleTop (27.0.0+12) rather than urea so uptake of N by the grass is as effective as possible and increase the rate to 2.5kg N/ha/day on 2nd cut for maximise growth.
Be prepared to spread slurry more thinly rather than be caught out by having to leave cutting until six weeks after the last application.
Even if you are able to apply 30m3/ha of 4% DM slurry, you will be well short of the RB209 recommendations for N, P K and S. In terms of Nitrogen alone, such an application will only provide 19 of the 100kg/ha recommended for a 5t DM/ha grass crop so bagged fertiliser is essential to maximise returns.
So, if you usually only take two cuts, it might be worth considering a third cut depending on how things look. There’s a lot to be said for more frequent smaller cuts, as in a multi-cut system, when conditions are as they are. And be flexible; maintain grazing efficiency and if paddocks get ahead of you, take them for big bale silage, rather than being lax on grazing and losing grass quality in grazed as well as cut swards.
3. Don’t delay aftercut nutrition
Delaying aftercut fertiliser applications can have a significant effect on subsequent production and yields.
Ideally you should put your aftercut fertiliser on as soon as you have taken your first cut. Previous research has established that delaying this for a two week period will lead to a loss in potential yield of 20 to 25%.
In production terms, this means you will lose about 370kg/ha fresh weight for every day you delay applying aftercut N which over the two week period equates to 1.0t/ha of dry matter production.
4. Don’t skimp on Potash if you want high energy silage
New thinking is also highlighting the importance of potash when it comes to delivering grass quality.
It’s been known for some years that Phosphate is vital for energy capture by plants through photosynthesis so maintaining soil indexes at 2 is essential to maximise yield, but potash is also key to quality – particularly energy content.
In trials over three years where 320kg potash/ha have been added to soils with K index 1, the average ME increased from 10.9 to 11.5 MJ ME/kg DM which in terms of return on investment with regard to milk production and feed costs savings is considerable.
Use a True Granular Compound rather than a blend to maximise the landing sites for P and K, and to achieve the highest response from them.
5. Make full use of Sulphur to boost crude protein and yield
Sulphur is also increasingly seen as an essential element in the quality equation with numerous trials highlighting its role in terms of maximising crude protein levels as well as facilitating better Nitrogen utilisation.
Sulphur is essential in the production of two vital amino acids - methionine and cystine – and without it proteins cannot be synthesised efficiently.
In one trial, where sulphur levels were restored to optimum, proteins increased by 7% and yields lifted by nearly 2.0t/ha and at another site a 1.0t dry matter/ha yield lift over the farm’s standard practice urea regime was recorded whilst proteins increased by 5%.
CF SingleTop (27N +12SO3) is a good starting point with Multicut Sulphur (24 - 4 -13 (7SO3) ideal if you want to address P & K shortfalls too.