Webster’s New World Dictionary defines the word stymie as follows: noun – “(golf) the condition that exists on a putting green when an opponent’s ball lies in a direct line between the player’s ball and the hole; any situation in which one is obstructed or frustrated; verb – to be an obstacle to; prevent the advancement or success of; thwart or stump.” For me, an almost universal example of this term could be illustrated by this sentence: Thousands of acres of standing corn stubble provide visual proof that a promising winter forage (cover crop) program has been effectively stymied.
Corn harvested as whole plant silage in late summer or early autumn should immediately be followed by a planting of a winter grain such as rye, wheat, triticale, speltz or barley. These cold-tolerant small grains utilize the moisture and warmth that are provided by Indian Summer. Summer annuals like sorghums, corn, soybeans, etc. cannot take advantage of these two production factors – usually they’re all dead, due to harvest or frost. In my earlier days, in a crop advisory capacity, there were more pronounced yield advantages for long season corn varieties compared to shorter season. In most of the 1970s, during my career as an agronomy Extension agent in central New York, a 100-day corn didn’t outperform an 80-day corn by 25%, but the performance gap back then was still a significant 10% – 15%. In the last 4.5 decades, due to the skills of plant breeders, both land grant and proprietary, that superiority gap between “longer season” and “short season” has essentially been halved. Therefore, many corn growers have opted to choose shorter varieties, particular for silage.
With large swings in more modern weather patterns, corn crops that successfully reach optimum maturity turn out to be a more cautious approach toward economically sensible forage production. Variety trials in the last couple decades have shown that corn breeders’ efforts have produced higher yields from traditionally shorter season varieties. Longer season corn varieties don’t automatically guarantee the grower significantly higher yields. Let me prove my point by tapping into the wisdom of Certified Crop Advisor Tom Kilcer. I’ll quote what he wrote in his November 2020 Crop Soil Newsletter at advancedagsys.com: “First, based on the Cornell test plots, there is only a slight, but consistent, yield increase from longer season corn. There is also an increase in the risk to that crop of not maturing, or having to harvest in late season mud, compacting the soil for long term yield loss. The other benefit of shorter season type is they allow double cropping with winter forage, which takes more advantage of the full growing season than do long season varieties. This can directly increase your yield per acre 30% – 35% per year while simultaneously conserving soil and nutrients and improving soil structure for long term yield gain like cover crops on steroids.”
The Cornell data behind Kilcer’s statement showed that when we shorten the corn season, in terms of growing degree day (GDD) requirements, we lose, on average, three-quarters of a ton of silage for every five-day reduction in growing season requirement. On average, a growing day consists of 20 GDDs. The yield difference between varieties of the same maturity can be greater than that. Shortening the season from 95 – 100 days to an 85-day variety would, theoretically, lose about three tons of silage per acre, or roughly one ton of dry matter. Kilcer wrote that if we get the mature corn silage crop harvested before Sept. 10 in the Albany area, the winter triticale can be in the ground on time and yield over three tons of dry matter (approximately eight tons triticale silage) per acre. This three tons of triticale dry matter increase clearly replaces the corn silage dry matter loss caused by planting the shorter season corn. Quoting Kilcer again: “The slight decrease in corn (silage) yield is more than offset by a three-fold increase in total yield of winter forage that is far superior in supporting high milk (production), comparing to the corn silage you are giving up. Slightly shorter season corn varieties will allow you to maximize the winter forage potential.”
Kilcer’s batting average with fall-planted winter forages surviving into spring is extremely good, but sometimes he and the cooperating farmer do strike out. In that case, if the hay stand doesn’t survive winter, he said their recovery move is to simply no-till oats very early in spring to take advantage of any available nitrogen and the cool spring temperatures to capture as much of the early growing season as possible. By mid-June, when the oats are at flag-leaf stage, they harvest them as silage, then immediately no-till brown mid-rib (BMR) sorghum or sorghum-sudangrass hybrid into the oat stubble as a second forage crop to be harvested. This way they get two crops, where before they had none due to the failed winter forage.
I want to expand on that early oat seeding panic recommendation of Kilcer’s. I believe that such will fit in nicely with so many standing stubble scenarios. Thirty thousand sticks of standing stubble per acre, poking through an inch or two of snow, prove to be quite an eye-catcher. Since herbicide residue threats to nurse crops and seedings aren’t nearly as prevalent as they were when triazines basically ruled, here’s my spinoff suggestion: As soon as the field is dry enough to not pack mud on disks, lightly disk the stubble in. Then, when the coulters can cleanly open the soil for dropping small grain seed, drill about two bushels per acre of oats; it’s good to throw in two to three pounds/acre of your favorite clover as a nitrogen fixer. Harvest at flag-leaf stage, like Kilcer recommended, and follow with no-tilled sorghum or sorghum-sudangrass. Or, if you’re brave enough, plant some – but not all – of this piece to some really good short-season corns.