Forage Inventories: Should I Take A Fall Harvest?

As summer starts winding down you should have a fairly good idea of forage inventories. Any supplies of corn silage should be approaching their annual minimums.

As summer starts winding down you should have a fairly good idea of forage inventories.

Any supplies of corn silage should be approaching their annual minimums. Not that you should be almost out, since ideally you should have enough to continue to feed “old crop” corn silage until the end of the calendar year or perhaps a bit longer. But soon the remainder of the 2016 crop will be supplemented with fresh-chopped corn, and by about the end of September your corn silage inventory should be at its annual peak.

By now you should know where the new crop corn will be stored – and not on top of (if you have tower silos) or in front of (bunker silos) last year’s corn silage. You don’t want to bury well-fermented silage – you want to feed it!

Some farmers put up one or more bags of corn silage to feed between corn harvest and when the new crop is fully fermented, a process that usually takes several months. Another way to accomplish this, particularly on larger dairies, is to have enough “old crop” corn silage in a drive-over pile for three or four months of feed.

Farmers have long known that cows often drop in milk if they’re fed unfermented (recently chopped) corn forage. Part of the problem is that rumen bacteria take time to adjust to what is a very different feedstuff with a much higher pH.

But it’s not all due to what my old friend Dr. Charlie Sniffen calls “rumen buggies”: We now know that starch digestibility increases considerably with storage time, not reaching its peak until after several months of fermentation.

Your 2017 corn crop: Harvest for silage, grain or …?

There are readily available silo capacity tables, online and elsewhere, that will approximate how much silage you have in each of your storages. By now you should have some idea of the yield of your corn crop – good, bad or about average. Using this information – what you have in inventory and approximate production – should result in knowing about how many acres of corn you’ll need to meet the needs of your herd. (If you won’t have enough 2016 crop to feed through the end of 2017, or if you have a big crop be sure to put up enough extra this year so that you won’t be in the same situation a year from now.)

If you won’t have enough, now is the time to start making plans to purchase some at harvest. If you know that you’ll have more than enough, you may want to harvest some for grain (using your own equipment or by having it custom combined). Another alternative is to sell surplus corn either by the acre or by the ton. My preference would be to sell it by the ton since the seller often winds up with more income and there’s less chance for a disappointed buyer if the crop yields less than anticipated. When corn grain prices are low you can expect more farmers to be willing to sell their surplus as whole-plant silage.

Is this trip really necessary?

A decision farmers growing alfalfa and alfalfa grass need to make each fall is whether they should take a fall harvest. Following is a brief true-and-false “quiz” on this decision:

Alfalfa repeatedly harvested at the bud stage enters the fall in a weakened state because it didn’t have enough time between harvests to adequately recover root reserves.

True. Root carbohydrates aren’t fully replenished until the alfalfa plants is in bloom – something that often doesn’t happen for the entire summer. In fact, modern alfalfa harvest management may result in the farmer never seeing an alfalfa blossom from seeding until the field is rotated out of alfalfa.

Taking a fall harvest of alfalfa following a summer of bud-stage harvest will usually result in a lower first-cut yield the following spring.

True. This has been proven by research in the upper Midwest. It’s not easy to fool Mother Nature.

Leaving a big yield of alfalfa in the fall can result in it lodging (falling down) and smothering the alfalfa.

False. I cannot remember the last time I saw a “big” yield of fall-grown alfalfa. The crop may look like it will yield well, but those large leaflets can be deceiving. What usually happens is that frost kills the top growth and the leaves fall to the ground. There aren’t nearly enough leaves on fall-grown alfalfa to smother a healthy alfalfa plant. In some winters, especially when there isn’t a heavy snow cover, many alfalfa stems – now leafless – remain standing all winter.

If an alfalfa field isn’t harvested in the fall the farmer, may have to deal with the dead alfalfa stubble in the first cut the following year.

Both true and false. While it’s true that an open winter can seem to leave a lot of bleached-out alfalfa stems, research has shown that the impact of these stems on the quality of the following year’s first cut is quite small – about 1 percent higher neutral detergent fiber than if there weren’t any old stems in the forage. The only time I’d be concerned about the presence of a small number of old stems in the new crop is if the alfalfa is baled for dry hay and then sold to horse owners, some of whom are notoriously picky about the forage they buy. Not that those old stems would hurt a horse, but appearance is important.

My recommendation regarding fall harvest of alfalfa and alfalfa grass: Take a fall harvest only if you need the forage.

Fall-harvested alfalfa is certainly not my favorite forage, and I’ve heard other farmers say that fall-harvested alfalfa silage doesn’t feed as well as the forage analyses suggest it should. Expect that silage fermentation has something to do with it. Frost and even an extended spell of cold weather can deplete the naturally occurring populations of fermentation bacteria.

It’s often cold when we ensile this forage. It’s also cold when we harvest and ensile the last of our corn crop, but corn contains a lot of plant sugars, which are the food of fermentation bacteria. Finally, fall-harvested alfalfa is usually high in crude protein – almost always over 20 percent crude protein (CP) and often 25 percent or higher. By comparison, corn silage is about 8 percent CP. The higher the crude protein in a crop, the harder it is to ferment.

So, if you don’t need the forage, park your mower-conditioner by about Labor Day and let your alfalfa enjoy an uninterrupted fall of growth to replenish root carbohydrates.