Timing is Everything
Photo by Schick/morguefile.com.
In last month's column I discussed corn planting. By now, unless spring weather was really wet, most farmers have wound up spring planting - both corn and hay crop forages - and finished much of their first cut. However, what's more likely is that some farmers will be finished with these chores while others will have barely started. While it's true that June-harvested forages have higher yield than the same fields harvested in May, timely harvested forages will usually produce not only more milk or livestock weight gain per ton, but also more milk, beef or lamb per acre. It doesn't cost any more to harvest hay crop forages on time versus a week or more too late. There may be more yield per acre in late-harvested forages, but the farmer will be paying the price for late harvest for as long as it takes him to feed the forage out. It's the old case of quality versus quantity.
Many years ago, when I was a regional agronomist in northern New York with Cornell University Cooperative Extension, I worked with a man who had recently taken over operation of the family dairy farm from his father, who had retired. The father had been a fairly good manager, but the son could never get anything done on time. Regardless of weather conditions, he was always about a month behind his neighbors. When other farmers were planting corn, he was dragging his moldboard plow and tandem disc out of winter storage: "Guess I'd better see about changing points on the plow." When others were harvesting the first cut, he was just getting around to corn planting; and when it was time for second-cut alfalfa, he was checking out his mower-conditioner and thinking about first cut, which had long since been in full bloom. This meant that not only was he always feeding low-quality alfalfa, but his corn, because it was planted well into June, was often harvested for silage long after a killing frost.
Not surprisingly, milk production suffered, even though he had to feed plenty of grain in an attempt to compensate for poor-quality forage. However, as good farmers know, there's no way to fully compensate for poor forage. It was a frustrating experience for me, since the farmer didn't seem at all bothered by getting nothing done on time. My frustration didn't last long, since the farmer was soon out of business and the cropland sold to his farmer neighbors.
Making a case for late-harvested grass
There's a saying, "Never say never," and this holds for the timing of forage harvest. Timely harvest of forages should almost always be the goal, but is there never a place for late-harvested forage?
When I was managing the crop operation at Miner Institute, we seldom got all our first-cut grass harvested and ensiled before the alfalfa came into the full bud stage, generally considered the ideal stage for harvest. Each spring we started harvesting grass when it was in the midboot stage, and we continued to put in long days mowing and ensiling it until the alfalfa in our alfalfa/grass fields was in the full bud stage. Then we harvested alfalfa/grass, beginning with the fields with the highest proportion of grass. By the time we were finished harvesting alfalfa/grass, the remaining (unharvested) grass fields were usually headed out and, therefore, no longer what we considered "milk cow forage." We then harvested this grass, ensiling it in a separate silo and feeding it to heifers and one group of dry cows.
One day the dairy nutrition consultant responsible for the heifer rations said that he wanted to talk to me about that late-cut grass silage. I became a bit defensive and started to explain that there just weren't enough hours in the day for us to harvest all of our grass in the boot stage. However, he stopped me midsentence, saying, "No, I really like this forage! The heifer rations include a fair amount of corn silage, and feeding late-cut grass silage along with the high-energy corn silage works very well, allowing the heifers to grow without getting fat."
Since then I've discovered that a number of other farms use late-harvested grass in a similar fashion, storing it in a separate silo and feeding it to one or two specific groups of dairy cattle. There are ways to use a wide variety of forage qualities on a farm, but it requires a plan, and it's better to figure out the plan before the forage is ensiled or mowed away in the hay barn.
Paying the price for missing the boat on forage harvest
The above example is the exception to the rule, and even then there are prices to pay for late harvest. Grasses mowed in the boot stage almost always bounce back - start regrowing - faster than those harvested after they've headed out. This is particularly true if the proper stubble height has been maintained, which for most forage grasses is at least 4 inches of stubble. As has been mentioned before, that's because, unlike alfalfa and other forage legumes, the nutrients in grasses that will be needed for regrowth are in the bottom few inches of the aboveground portion of the plant. Harvesting at less than 4-inch stubble height robs the plants of nutrients, considerably slowing regrowth.
Another factor is that forage grasses such as timothy, orchardgrass and tall fescue don't regrow as well once the soil temperature warms up. That's why they're called cool-season grasses! Harvesting the first cut when the plants are in the boot stage (mid or late May in most northern areas), when soils are still cool and moist, can really give a boost to regrowth. Grass fields that are mowed after the plants are fully headed will regrow more slowly, and there won't be nearly as much growing season left. We found that the fields we mowed after finishing alfalfa/grass harvest often could be harvested only once more instead of two more times. So the additional yield we gained from harvesting a late first cut was at least partly offset by the impact of one less harvest per season. The profitability of a forage program involves not only what you do, but when you do it.
Ev Thomas has worked as an agronomist in New York for 45 years. He has written our Forages column for 15 years and has been an expert contributor on a number of other topics.