The April 12, 2023 Nebraska Drought Monitor shows 98% of Nebraska in moderate to exceptional drought (D1-D4). We will keep praying rain; it will rain again one day! There’s truly concern about the dry conditions due to lack of subsoil moisture. Those planting last week shared how conditions were changing with the winds making surface soil hard. A few colleagues and I put together the following info. about planting into dry conditions in CropWatch that I will share this week.
I didn’t talk about planting deeper last week, but for those asking, Bob Nielsen, emeritus professor at Purdue said corn can be seeded 2.5-3” deep if that’s where uniform soil moisture is located in order to achieve uniform germination and emergence. We don’t recommend planting soybean deeper than 2.5”.
In general, we would only suggest watering before planting if the planter needs higher soil moisture levels to work well. So, if the soil is too hard, too powdery or cloddy, it may be worth running the pivot. Another situation to consider pre-watering is if greater than 180 lb/ac anhydrous ammonia was applied in a strip with less than two inches of moisture received since application to help reduce ammonia burn to the corn. Otherwise, our recommendation is to run the pivot after you plant if needed.
The usual recommendation is not to run a pivot when temperatures are below 40 degrees. Last year, several pivots were operated below 40 degrees without problem, but keep in mind with low dewpoints the pivot can ice up when the actual air temperature is well above 32. So, if you do choose to run in these conditions, keep a close eye out for ice buildup, which can collapse the pivot.
Bare, powdery soils will seal over very easily from rain or irrigation, so keep an eye out for runoff problems even with fairly low application amounts. And make sure if you do irrigate that you put on enough to get water down to the moist soil below. This is particularly a problem with tillage or where fertilizer knives have been used and dried the soil out.
It’s important that herbicides are activated with 0.5- to 0.75-inch of rainfall or irrigation, preferentially within five to seven days after herbicide application. If moisture received is less than this amount, some herbicide products have the potential to remain on the soil for up to 14 days without being fully activated. We will have to see how the high winds blowing soil and removing soil particles containing herbicide impact future weed control.
For those who applied dry or liquid urea on the soil surface, particularly without the use of an inhibitor, irrigation of 0.5-inch can help with incorporating the urea into the soil and minimize urea loss. If irrigation is not available, an inhibitor was not used and no rainfall has been received within seven days, monitor the corn crop to determine if nitrogen deficiency occurs due to nitrogen loss.
John Mick, Pioneer agronomist, shared last year that water from irrigation wells in the southern part of the state often is around 50-53°F, with it slightly less in temperature as one moves north in the state. These temperatures are not a problem to be concerned with regarding any negative impacts to seeds imbibing water.
Lawns: For those struggling with lawn winterkill, Kelly Feehan shares, “Some lawns may come out of winter with dead areas in need of reseeding. While early September is the ideal time to seed Kentucky bluegrass and tall fescue, spring seeding success can be improved by seeding as soon as possible so seedlings establish roots before summers’ heat. Improve seed to soil contact by aerifying, power raking, and/or hand raking right before seeding. After seeding, a light raking will further mix the seed and soil. Water lightly and often to keep the seedbed moist. Mulch will help conserve water, but use lightly so at least 30 to 40% of soil is still visible through the mulch. Use low rates of fertilizer, about one-half to three-fourths pounds per 1000 square feet, applied every four to six weeks until mid-June; and keep the area well-watered all summer while avoiding overwatering which can lead to poor rooting and disease.” Also avoid crabgrass preventer to newly seeded areas.
Evaluating Wheat Stands handout by Nathan Mueller: https://croptechcafe.org/wp-content/uploads/2020/04/Evaluating-Winter-Wheat-Stands.pdf