Farm Horizons, April 2014
Tips for good stands this spring
By Dave Schwartz
Over the years, I have been called out on many stand issues where growers were undecided if they should replant or not.
The tough calls are when plant populations are borderline, and there is still enough time to get the crop replanted. Some of these situations could have been avoided and some not.
When mother nature deals us a cold, wet spring, you can almost count on some stand issues. Planting into warm moist soil solves most planter errors.
Below are the most common problems I have seen, and some ideas on how to avoid stand loss.
• One of the most common problems I run across is too much trash (crop residue) in the row, which increases gaps and delays emergence. This was never a problem when corn yields were 100 to 120 bushels per acre, but now, when yields are going over 200 bushels per acre, I hear more and more complaints about all the trash that growers need to deal with at planting.
When I scout fields that have been in continuous corn, I often notice gaps between plants. When I dig down to find what the problem is, I often find a piece of corn stalk covering the seed. Row cleaners are a must for precision planting in continuous corn.
• Depth control is also a common problem with marginal stands. Planting conditions change from day to day, so growers need to monitor seed depth when moisture conditions change or when moving from one field to another.
Most fields in Wright and neighboring counties have several soil types, so this makes it difficult to have one uniform seeding depth from fence row to fence row.
Think how differently clay knolls and peat soil plant. Ideally, I prefer 2-inch planting depths for corn seed and 1.5 inches for soybean seed.
• Planting in cold, wet soil is a recipe for a crop disaster. This is more understandable when growers are forced to plant in wet fields in late May with no drying weather in sight. We have had years when we either plant in mud early or plant in mud late. What should be avoided is planting in cold wet soil, early in the planting season.
Soybeans are more forgiving in low plant populations than corn. Soybean plants naturally develop more lateral branches when plant populations are less than optimal. This is not the case for corn, where even late emerging plants take away yield.
Normally, I would say growers are better off sticking with a marginal stand than replanting. Corn yields begin to drop off when planting is done some time after the first week of May. For soybeans, yield reduction begins sometime around the second week of May.
Replanted fields are normally planted after the optimum date and shorter season products are planted; both of these practices reduce potential yield.
For growers who are undecided whether they should replant or not, it may be a good idea to get a second opinion from their local agronomist.