Cutting silage after spreading lime

morning delight

Folks
I may be in a spot of bother here. I've spread ground lime 2 weeks after taking the first cut of silage and the grass is just getting a bit leafy.

The problem is I intend taking a second cut off this ground. A neighbour has told me you shouldn't cut silage after spreading lime as it sticks to the leaf and the silage won't ferment properly:(.

Another neighbour spread lime on ground that has much more growth having taken the first cut in early June.

So folks, what's the story? Can I take a second cut?

whelan1

i know this is not much use to you but i always thought that lime was spread in the back end and in the spring for a reason

theroad

I googled "silage lime" and found this on a Glanbia website:
"Lime can be safely applied to grassland at any time of the year. It is important to ensure that lime is well washed off grass before stock graze it, as it can cause scouring. Lime should not be applied to silage fields in the Spring prior to cutting or between cuts as any traces of lime in the pit would have a very negative impact on preservation."

Not much help, but it seems fairly clear.

morning delight

Talked to my farm advisor. Yes it shouldn't be done but as our politicians say "we are where we are"!.
It takes a few months to wash into the soil. Luckily it hasn't much cover at the mo so graze it tight and close up again. (I've no option as I need the silage). N and slurry will still be ok. Pray for plenty rain and leave harvesting until as late as possible.
The silage that comes off it doesn't ferment very well and can be blackish in colour. The cattle will still eat it but the quality will be poor due to poor digestibility.
Advisor knows lads who've done the same and gotten away with it so hopefully with a good wash of rain, a tight grazing, and knock for silage as late in Sept as possible I may just get away with it!

Any further advise or experiences from lads that have been in the same boat is welcome

morning delight

My neighbour is in worse straights though as he's ground has been closed longer. Luckily he only needs about have of it for silage so he'll probably graze half and take he's chances with the other half:(

blue5000

How many tons to the acre did you spread? If it all gets washed off the grass I think you'll be ok. Does the grass absorb more lime from the soil the yr you spread it?You might try putting molasses on in the pit to help it ferment, as I don't think anybody puts acid on anymore.

morning delight

blue5000 wrote: »

How many tons to the acre did you spread? If it all gets washed off the grass I think you'll be ok. Does the grass absorb more lime from the soil the yr you spread it?You might try putting molasses on in the pit to help it ferment, as I don't think anybody puts acid on anymore.

Thanks blue
I was thinking of starting a new thread regarding acid to improve silage fermentation, as that is the problem with the lime. It alters the pH and doesn't allow the normal fermentation to occur. To my mind this would mean acids would probably be better than molasses. Never used any of these products though so I'll throw it out there in the hope of some advise based on experience!

morning delight

Well I knocked 15ac for second cut today on the land that got lime 8 weeks ago tomorrow. It got CAN 10 weeks ago. And I'm confident I'll get good silage from it.

So here's the science. Lime acts as a buffering agent and prevents the pH dropping and thus fermentation of the silage. Good silage is formed by the rapid formation of lactic acid and an associated drop in pH.

So how do you counteract this? 2 ways. The 1st is to apply acid such as formic acid. There is a non-corrosive version out now but it would cost ~€2 per round bale.

The second is to wilt the grass, thus removing the need for much fermentation at all.

In order to find out where I stand before knocking the grass I've had a "buffering capacity" test carried out on the grass from the field. A bit like soil sampling, I took 5 samples from different parts and mixed them together to form one sample for analysis. And the news is good my friends, the grass has low buffering capacity. This means the pH should drop quickly and proper fermentation should take place.

Just to be sure to be sure I'm going to shake it out and give it a good wilting anyway. It's for suckler cows so some loss in quality isn't an issue.

My neighbour who was in worse straights (N out 12 weeks and heavier cover of grass at time of lime application) also did the test and the result was good from him as well (i.e. low buffering capacity).

It appears our saving grace was the weather. It was applied on a drizzly day and it rained daily for the following 2 weeks after putting it out. This washed it off the grass and got it down into the soil.

I've another 7ac where the result only came back as average buffering capacity. This area got a heavier application and remained dry for a week after application, thus the lime has stuck to the grass. It has a lighter cover and the CAN isn't out as long so I'm going to sit on this field for a few weeks - hopefully we'll get another dry spell!