By Ron Hoover
A recent Field Crop News article summarized the possibility for having to reseed some forages where excessive soil moisture may have drowned out plants. While we’ve seen many areas like this, we have also probably seen those sections of fields where soil characteristics wouldn’t qualify as being “wet”, but where regrowth is either thin or absent. I’ve encountered numerous areas like these in several of my hayfields in recent weeks. What should a manager do about them, if anything?
The first situation was in an April 2014 seeding of alfalfa/orchardgrass. First cutting this year was made in mid-June after several weeks of frequent and sometimes heavy rain. With a forecast of 3 decent days to dry hay enough to small square bale it, the mower-conditioner went to the field as the rain from the last shower was dripping off the plants (sound familiar?) Soil moisture was very near field capacity, and soils were easily compacted, especially on headlands and near obstacles in the field where tractors and implements needed to repeatedly go around them. It was in those areas where forage regrowth, even 2 to 3 weeks after harvest, was so poor that I began contemplating spraying out those areas and no-till drill them during mid-August. But, when I mowed second cutting 2 weeks ago, I found that while those areas didn’t have much to mow, the drill rows were easily seen and much of the alfalfa/orchardgrass in them was green. I looked at the field over the weekend and those damaged areas are showing regrowth nearly as strong as the non-trafficked areas. I also suspect that the freeze-thaw that will occur this winter will further help to loosen those soils and the field should look great next spring.
A second situation is a field of pure orchardgrass. The second cutting was taken in late June, also in the midst of much rainfall. Because the stand was a 4-years-old, I thought that it would withstand the wheel traffic and compaction better than if it was a new stand. It did not. As with the former situation, most of the field is OK. But headlands and areas where multiple trips with equipment were necessary do not look as good. I mowed this field yesterday, and where the regrowth was thin, dead plants were easily seen. Not only were many plants dead, but it appears that the earthworms and other soil life that consumes dead material are doing well as long streaks are totally void of even dead orchardgrass plants. It appears that sections of this field may benefit from some reseeding in the next few weeks.
Why the difference between these sites, when the soils and soil moisture was similar? While not a scientific study, I have to believe that the alfalfa with its heavier taproot was responsible for helping to resist at least some of the compaction. Both species in the mixed stand likely benefited from the reduced damage to soil structure. In the end, it should be noted that not all forage stands respond similarly to ill-timed field operations, and that sometimes allowing a little time to pass before making costly management decisions can allow some wounds to heal.
Source:psu.edu