March has been a weather roller coaster coming off a weekend with arctic chilling temperatures and snow into more typical spring conditions. Soil temperatures are definitely improving to where we need to be for corn based on local data from Jackson, but ground remains heavy and next week’s forecast includes rain and nighttime temperatures in the upper 30’s after mid week. Soil temperatures for the past four days at Jackson from a recently sprayed cover crop and a no-till field are in Table 1. Today (Thursday) was the warmest at 55 to 57 degrees but soil was still too wet to release soil cores easily from a soil probe.
| Table 1. Soil Temp at 9 am and 2 inch soil depth in Jackson TN week of March 14-18 | ||
| Date Soil Temp in Jackson | Cover Crop ⁰F | No-till ⁰F |
| 3-14 | 44 | 44 |
| 3-15 | 50 | 50 |
| 3-16 | 54 | 53 |
| 3-17 | 55 | 57 |
This spring is starting out pretty typical with weekly showers and temperature fluctuations, which can impact corn germination and stand quality. Conditions need to be right to get a uniform stand and adequate plant population the first time. Have equipment calibrated and ready to go to take advantage of windows of opportunity should these weather patterns continue into April.
Plant corn when soil is dry enough to minimize sidewall compaction with the planter, temperatures are at or above 50 degrees for multiple days, and weather forecast is favorable for the 3 days following planting. Reduce planter row unit and closing wheel downforce to help lessen compaction when planting into soils that are borderline heavy. Seed should be planted no deeper than 2 inches, or slightly shallower if several days of cool weather are expected after planting. Increase seeding rate by 5% above desired stand (under good planting conditions) or by 10% above desired stand if emergence conditions are a concern.
Other corn planting tips:
- Tennessee crop insurance full coverage dates for corn are March 21 to May 20 (West TN) and May 25 (TN river and all counties eastward).
- Plant non-irrigated upland fields in March or by mid-April for optimal yields if conditions allow.
- Avoid planting within 24 to 48 hours of a cold front where temperatures are expected to fall below 40 degrees. This will reduce the possibility of chilling damage to germinating seed.
- When planting corn in March and early April, plant hybrids with good emergence vigor or stress emergence scores in order to help lessen impact of soil temperature fluctuations on seed germination.
