Silage 2022

You can have too much N and K in silage too.

It's not unknown for big crops of black silage going in and black silage in the winter.

Neighbour with an acre cottage plot proudly had 15 bales/acre. And sold to a dairy farmer. Dairy farmer had to dump every bale in the dung heap.

Don't think so. I think that would be 27kg of N. As far as I know the 18 here is % of the bag. So 18% of 50kg bag, or 9kg per bag. How that relates to units is a mystery to me. I asked about this here previously and got many different answers. Teagasc aren't any good to answer it in their literature too

If you are in enviormental schemes you have to soil test for them. Generall they run five years so you are testing every five years. Units are easy when you get used to them. Historically fertlizer came in 50kg not 500kg bags ( it can still be got tha way if you have no value in your back). What the 50kg bag contained indicated the units.

18-6-12 is 18 units of N,6 units of P and 12 units of K.

Urea is 46 units of N.

The rest of fertlizers are the same.

Traditionally silage was considered to need 100 units of N, 30 units of P and 100 units of K per acre.

On average during april and May grss can use 2 units of N on average per day. Average is the operative word. In early april it may struggle to use a unit/day but by mid may it could be usind 3/day. That is who some lads cutting early (10-14th May) are sometime having problems with silage as if April is a poor growth month the N may not be gone out of there silage.

Correct. It does what it says on the bag literally. Just don't forget that not all big bags contain 500kg, for example some Urea products come in 350kg bags.

Not always. Nowadays you need to do soil tests, this will give you an accurate picture of what fertilizer to spread. With the price of fertilizer it really is a no brainer to do the soil tests and they are relevant for 5 years as the soil will not change that fast.

Do the soil tests and if you are unsure of the results throw them up here and someone will be able to go through them with you.

Blends like cut-sward are formulated to give the correct ratio of what a typical silage crop needs but no more. But would be the best option if you are spreading blind

Thanks for that

I've saved that for future reference . I used to understand but had all forgotten.

Alarmingly I'm not that old to start forgetting stuff

Yes

Grass will head out at some stage. When gras starts to head out it redirects all its energy into producing seed. First the grass flowers and then seeds out. cattle cannot digest the grass seeds. Flowering is not a problem.

If you do not do first cut until mid/late June quality will be poor. While it's adequate for Suckler cows stores will not put weight on. If you have ryegrass swards they will use up the N. Generally I hit about 85-90 units N for first crop. There is no clover at present in my silage swards. I intend to try to change that in the next few years.

I usually start applying N by April 1st. That give me 55 days to cutting or 1.65 units N/ day if I cut on the 25 th May. I would not consider the amount I spread excessive.

Cut swards is not adequate for silage. It's is actually supposed to be used with slurry. If growing silage with bag fertilizer only 5 bags of 18-6+12 is nearly in the ball park.

While you may get away without spreading any fertlizer for a year or two and have adequate crops over time your crops will deteriorate. The growth rate will continually slow down and the feed value will keep reducing.

I was just about to post about that. I didn’t realise it was a teagasc recommendation now but for a good few years now 80-85 units is all I’d put out and had no reduction in yield or quality from when I was spreading 100-110 units.

You have to remember that Teagasc has also pushed the recommended cutting date back to early/mid May. You are taking 7+ days of the highest growth period out of the equation.

Absolutely. A wet and windy May, fills the yards with corn and hay!

The timing of the weather we got in April and May could scarcely have been better for grass.

And a good thing, with the year that's in it!

The alternative way of getting the '4 bags to the acre' answer would be to divide the required 100 units by the 24 in the bag.

Cut sward isn't good enough if you haven't 2-3000gls slurry/acre out as well,