Corn Forage Harvest Off and Rolling

Corn Forage Harvest Off and RollingMost haymakers in the Northeast were satisfied with their 2022 first cutting in terms of quantity and quality. However, with darned few exceptions, satisfaction ran out pretty dramatically when it came to second cutting, particularly with quantity. Most growers I spoke with said that this year’s perennial hay harvest ran about one-third to one-half of last year’s. And most of them said that the poor second cutting yield was caused by woefully inadequate precipitation on their fields during June and the first half of July. Proof of last year being a fairly good hay year for most growers in our region became quite evident in the amount of hay for sale all through last winter and this past spring. Meager second cutting yields this year have prompted me to strongly suggest that local livestock people start lining up prospective cold-weather forage purchases from hay growers – particularly those with few or no livestock of their own.

Disappointed hay growers who also produce corn are hoping that their corn silages will yield neutral detergent fiber with higher digestibility. Sarah Fessenden, livestock nutritionist for the Ithaca-based Dairy One Cooperative, said that if the corn crop behaves more like a fiber forage than a starch forage, this scenario could offer a viable feeding strategy for some farms. Logically, the more fibrous feeds should be fed to dry cows and heifers, leaving the starchier feeds for the lactating cows. These feeds can’t be accurately classified without laboratory analysis. At first glance, many corn stands are evidencing less lignification, with thinner and more flexible stalks. Water shortages that hurt perennial second cutting regrowth may actually result in better whole plant digestibility for nearby corn stands.

The vast majority of corn stands still have some time to go for optimum corn silage maturity. But some areas – particularly those with shorter corn season varieties – are being aggressively chopped. Fessenden stressed that some dairy farmers feel compelled to start chopping early, but those eager beavers will lose the starch potential – thus potential milk production support – that this season gives us. Quoting Fessenden: “I am seeing a separation of fields that are 30% whole plant dry matter (DM) and 30% starch, and fields that are 31% DM and 34% – 35% starch. The latter will dry down at 0.75% – 1% per day. The fields where the DM and starch are even will be the more traditional 0.5% per day. This is why whole plant dry matter is so important to monitor … above milk line and visual appearance.”

While it’s still early in the harvest season, let me make the following five points: first, the record high growing degree days (GDDs) in the Northeast put its stamp on some corn, with promised impressive yields; other areas have had ear fill issues from untimely dry spells. But overall, it’s safe to say that the pluses clearly outweigh the minuses. Second, fields appear green from the road, but very often ears have lower moisture content, which will accelerate dry-down. Third, the risk of custom harvesters opening up the processor (if fields appear green) will result in half-nicked kernels. Fourth, operators without a processor may start too late for the kernels. Fifth, in many situations, there’s enough time – 10 days to two weeks from this paper’s date for corn that is 30% whole plant DM, particularly shorter season varieties – to be harvested properly as well as ensile properly.

Let me put a face on typical GDD observations in our region. Crops need four basic items to perform satisfactorily: (1) sunshine, (2) warmth (both air and soil), (3) precipitation and (4) soil health (and nutrition). Only over the fourth item do growers have real control. I take a simple approach to measuring GDDs. The baseline for this measure is 50º F. Thus, a day that averages 70º is said to have amassed 20 GDDs. Interestingly, according to my August 2022 electric bill, this past month my hometown of Hartwick, NY, logged an average temperature of 74º. So, with 31 days, August accrued 744 GDDs (31 x 24). Compare that to August 2021, with an average temperature of 71º. Math work shows that August 2021 accrued 651 GDDs. Thus, compared to 12 months earlier, August 2022 enjoyed about 14% more warmth available for growing plants – assuming that the other three items aren’t limiting factors.

Let’s pay some attention to introducing this year’s corn crop to cattle diets, particularly if it’s extra wet (over 70% moisture). In olden times, folks would load up a flatbed wagon with green-chopped corn. Cattle loved it. But their owners disliked what free-choice green chop did to their milk production. Bombarding rumen microflora with huge quantities of new, unfermented roughage greatly disrupted these miniscule munchers. Rule of thumb here: for about five days, limit DM intake of green-chopped whole plant corn forage to about five pounds – Jerseys a little less, bigger cows a little more. If forage DM is 25%, then daily pounds fed should not exceed 20 (5/0.25). When introducing green-chopped corn to cows’ diets, if possible, just chop on the west side of the field: plants in the still-standing row can enjoy the solar radiation that their carted-away comrades are no longer consuming, helping them dry down just a little faster.

If the corn harvested for silage is off the field by the last day of summer there will be ample time to get a winter forage well-established before cold weather sets in. Take your pick of rye, triticale, wheat, barley or speltz to be planted on the corn stubble – disked if necessary. From a standpoint of conservation – minimized pollution and optimal soil health – it’s infinitely better to spread manure on a growing winter forage rather than on stubble and mud.

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