How is grass prevented from decomposing when farmers make hay and silage?

Question

I am researching silage making, and the most basic question is already posing problems, help .... please

Answer 1

The fermenting forage produces lactic acid, which preserves the forage.  If you smell silage, you'll notice is has kind of a vinegar smell, that's the lactic acid and in the absence of oxygen, it preserves silage the same way vinegar preserves canned pickles.

Silage can be grass, corn, alfalfa or almost any forage.  However, it must be approximately 30% moisture.  Too dry and it rots and too wet and stinky juice runs out everywhere, taking valuable nutrients along with it.

Compacting silage in bunker silos is accomplished by running over it whith tractors.  Compacting reduces pore spaces in the chopped material, thus forcing out the trapped oxygen.  Air (oxygen) must kept away from the silage by either airtight structures or plastic sheeting.  Since it's impossible to exclude all oxygen, that's why the outside layer is usually partially decomposed.  

Incidently, "baleage" is made by baling high moisture hay and using a special machine to wrap the bales in airtight plastic either individually or together.  The normal fermentation process then occurs.

Answer 2

Hay is field dried and baled and stored dry to prevent spoilage.  It remains in a dried state to keep it from molding just as many dried grains are stored once they are dried either at the mill or in the field and then they keep it stored dry.  

Silage bins are used as a mechanism to begin decomposition to aid in the digestion of the harvested grasses.  

The animal feed that has been stored as silage is much more beneficial and easier to digest for the animals eating it.  Less undigested grass material as even cattle have a difficult time digesting some grass without chopping it and storing it as silage.  Grasses are cut and  stored green - without drying - to begin the silage process.  It is an effective means of storing it until it is used.  In the colder areas it generates heat and can even catch fire but the heat keeps it from freezing.

Grass is not prevented from beginning decomposition when making silage.

Answer 3

As I am sure that know preserving grass as silage and preserving it as hay are two completely different processes, and  different concepts. Hay is made by cutting the grass and leaving it spread out in the sun until it dries enough (15% or less) that it can packed into tight bales without it spoiling. Silage is when the grass is cut and allowed to wilt, then it is chopped into small pieces and put into a silo at a much higher moisture content (around 60%). You try to compact the silage to remove as much of the air as you can, but you cannot remove all of the air. Bacteria will start breaking down the grass by converting sugars by fermentation and in the process make lactic acid so the grass becomes more acid. This is an aerobic process (requiring air) as the available air is used up and the higher acid content stops the decomposition and the grass is preserved as silage. As no more air is allowed to touch the silage it is preserved indefinitely. A couple of sites that can clear things up for you:

http://www.uaex.edu/Other_Areas/publicat...

http://www.woolfarm.com/makinghay.htm

Answer 4

nothing lasts forever, it all rots eventually. the grass does not age as fast as most things, but it does eventually decompose. The grass is cut fresh fresh, it makes it last longer. silage cannot be to dry or else it will catch fire and does decompose to that brownish colour, but it makes the hay sweeter. Hay must be dried, because if it is too wet it can catch fire. because hay is generally used within a year, it does not have time to decompose fully. It will bleach and lose some of it's nutrients but it will still be good for a couple of years.

Answer 5

Due to very high C:N ratio the bacteria cannot easily degrade straw in silage. Usually Carbon will be 30 times more than nitrogen which leads to immobilisation of bacterial activity on straw.

But hay is stored in bunkers and least affected. If we use both straw and hay, the most affected will be hay, becasue of more organic nitrogen in it than straw.

Answer 6

In silage, yes, removing the air by the sheer weight of the stored material is the key. Create an anaerobic state by packing the hay with a weighted tractor. If you look at a silage pile in a bunker silo, you will notice the first several inches on the top is black and rotten. That is beacause the first several inches cannot get the air removed. If done properly, however, the vast majority of the pile will ferment properly.

With dry hay, the hay is kept in the field, spread out, and allowed to dry by sun and wind. When the hay reaches 15% moisture, it can be baled, as that is dry enough that the hay will not rot in the bale. In fact, it will continue to dry down.

Answer 7

It has to be packed extremely tight.  Some silos are upright, some are in ground trenches/bunkers, and some are like giant trash bags that the air gets sucked out of.  No matter what kind of silo you use, or no matter how the silage/haylage is stored, it HAS TO be free of oxygen.  When it gets packed, it is allowed to ferment without decomposing.  

Have you ever smelled silage?  It smells like rancid vinegar.  That is because fermenting helps it to preserve.

We used in ground silos (bunkers), and drove tractors over the top to make sure that it was packed.  The places that were exposed to oxygen began to decompose and mold.  As you probably already know, mold can be toxic.

Answer 8

They let it dry before they put it in the barn.

Answer 9

it is dryed and put up out of the weather

Answer 10

When silage is in storage in the modern tall silo, or the older and shorter wide weighted covered silo, it protects the material somewhat like a can in that it keeps the air out. That is accomplished by the weight of the material in the tall tower on itself or the weight of the weighted cover on the shorter wide silos. Any decomposition is in effect helping preserve the silage. Take a look at the history of the silo to get a good idea of the process.