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First cut: Stop the loss

Seasonal challenge Seasonal challenge17-4-2020

As the soils warm and grass growth is on the rise, first cut silages will start for some within the next 4 weeks and for most; it is the most important harvest of the year.

What would a lift of 0.5MJ of energy in your first cut silage be worth? It is easy to lose 0.5MJ between a combination of cutting date, wilting, weather, ensiling, sheeting etc. Protecting this valuable ME could be worth in excess of £7,000 for the average farm. 

First cut silage

Protecting ME & CP

Getting the maximum yield of energy and protein out of first cut requires protecting what you have already grown within the crop. The dry matter losses that we see are mostly the energy and proteins we need for milk and meat production. 

Graph: Dry matter losses
The chart illustrates the likely dry matter losses at a range of grass silage dry matters. 

Too wet or too dry leads to higher losses, so hitting the 27.5 - 30.0% DM range achieves optimal from a losses and animal intake point of view. But wilting beyond this can reduce digestibility and intakes without milk or meat output just costs money. 

Last year’s first cut silages tested by ForFarmers showed:
•    A quarter were below 25%DM and therefore effluent losses were likely.
•    A third were above 35% and therefore likely to have in-field losses.

These losses can be minimised with best practice and the use of an effective additive. Of course dry matter losses can be even higher through instability at feedout so if using an additive ensure it will help prevent aerobic instability. 


The wet winter means that not all of the rolling that would have occurred has, increasing the chances of soil getting into the silage. Careful setting of the working heights of mowers and tedders/swathers will be needed to minimise soil incorporation. The bacteria, yeasts and moulds present in the soil will cause issues with fermentation and aerobic stability. A rapid fermentation is needed to supress their activity. Again an effective additive will pay dividends this year.


Fertiliser Spreading

Given that soils have had a rough ride over this winter, mineralisation of nitrogen and sulphur could be suppressed.

The grass will be hungry and raring to grow for second cut, so it’s worth getting applications of slurries and bagged fertiliser on aftermaths quickly following first cut so you don’t miss any growing days.

Application rates will depend on your target yield, typical rates are 70-75KgN/ha, but high growth potential areas might push up towards 90kgN/ha. 

Potash need is greatly dependent on soil index status. If you haven’t had soil test done in the last 3 years it is well worth getting then done to avoid over or under application of K. 

Index 2 soils will need 90kg/ha to maintain the index. Where slurries have been used then this will provide the majority of your potash requirements. Check with our forage team on application rates.

Sulphur will certainly be critical, especially if you are looking to maximise the crop’s sugar yield and protein quality. It’s inclusion is hugely cost effective. 


  • Target 27.5 - 30.0% dry matter. Be careful with wilting, especially if tedding as soil inclusion could be an issue this year.
  • As the first cut is so critical to next winter's profitability, use an effective additive to minimise losses and preserve silage quality.
  • Check your fertiliser plan for post first cut. Contact us if you would like us to help you review it.


For more details on maximising your forage, fertiliser plans or application rates please contact your local Account Manager or contact our Forage Team here.