MFA Agronomist Jason Worthington talks about the right time to plant row crops.
For years, growers have been told the earliest-planted crop is the best crop. Dataset after dataset have been presented by university after university to back up this information. Couple this data with the “get ’er done” attitude typical of farmers, especially in the spring, and you get a mindset focused on one thing: getting a crop in as early as possible.
There is one fatal flaw in this mindset—early is not always better.
To say early planting has no advantages is not true either. An increased likelihood of flowering during milder weather, avoidance of certain pests and the possibility of an earlier harvest are all benefits of early planting. However, all those factors combined will not outweigh the two most important criteria for raising a top crop: soil conditions at planting and seed placement.
The simple fact is corn’s yield potential can still be quite high when planted into June. We witnessed this last year. There were several examples of corn planted after June 1 nearly doubling yields of corn planted into subpar conditions in April and May. So much is determined by a corn plant’s early life. Cold, wet soils cause inconsistent emergence and development, which leads to competition against other corn plants and greater vulnerability to disease. Small corn plants also have a much harder time metabolizing herbicides at this point.
Perhaps the biggest drawback of planting in wet conditions is what the planter actually does to the seed bed. Sidewall compaction was a very common issue encountered in 2019, caused by planters smearing and compacting the sides of the seed trench as it moved through wet soils. This can cause emergence issues due to poor seed-to-soil contact, but often the damage goes unnoticed until some type of stress is introduced. Root growth is limited, leading to mohawk or hatchet roots. Nutrient deficiencies or drought stresses are more evident in these fields much later in the growing season when planting conditions are all but forgotten. Often these issues get blamed on poor fertility or drought or other things, but it was very common for stressed fields in 2019 to show evidence of poor planting conditions. For example, when you can see trenches following the corn rows at planting, it was likely too wet, and hindered root growth is the likely result.
It’s also important to make sure seed placement is correct. Of course, much of this is aided by proper calibration and monitoring of the planter’s performance. Setting depth and down pressure are important as are making sure seed tube meters and all moving parts are doing their jobs in singulation.
However, among all the things we can control, speed is the most critical. Urgency bordering on impatience becomes the enemy. Maintaining planting speed of 4.5 mph does as much for seed placement as any other practice. Sure we have “high-speed” planters, after-market “speed” tubes, and meters that can singulate at remarkable accuracy at high speeds, but singulation is a small part of seed placement. Consistent depth and placement in the seed trench are more important than singulation. Varying depth and placement cause not only geographic inconsistency but also temporal inconsistency, which relates to uneven emergence and development.
The goal of planting should be to get all plants up within 12 hours of each other so they are competing on an equal playing field. The late emergers are like the runt pigs of a litter that take resources from the healthy pigs without gaining at a profitable rate themselves. High-speed planters can provide geographic spacing consistencies, but even the best down-force systems struggle to compensate for row unit bounce when planting at high speeds. This causes higher inconsistencies in emergence.
With today’s equipment, most growers admit that they can finish their planting in less than a week. Moving from 4.5 mph to 6 mph means they can finish in roughly five and a half days instead of seven. How much yield loss is that one and a half days worth?
Though the advantages of early planting are real, they are also misleading. Yes, we want to take advantage of planting windows, but not at the cost of planting into cold or wet soils. If you drive a couple of miles per hour faster, are you accomplishing more? Maybe. But remember your goal—to raise yields. How do you achieve that goal? By giving your crop the best start from the beginning.
Read more from the MFA Precision Agronomy team at mfa-inc.com/PrecisionAg and at TodaysFarmerMagazine.com/crops, where Jason's article was originally published.
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