The warmer air, wind, and warming trend of soil temperatures have allowed for planting to begin for some. Last week I mentioned watching the soil moisture where seed will be placed as pre-irrigation may be necessary with the lack of rain most of us received. The winds continue to remove surface moisture and each field varies in soil moisture at seeding depth.

The decisions we make at planting impact the entire season. Aiming for fit soil conditions that are proper and even soil moisture where the seed is placed, warming trend of soil temperatures, and even planting depth are important. We saw how uneven emergence was last year with uneven moisture at the seeding depth. I recommend putting corn and soybeans in the ground at 2” (our research recommends 1.75” for soybean). This allows for buffered soil moisture and temperature conditions when planting. 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, particularly for non-irrigated fields. Don’t plant soybean below 2.5”.

Since 2004, we’ve shared the importance of planting soybean early (mid- to late-April or first week of May) to increase yields. We often hear a preference of planting corn and soybeans in as close to 50°F or greater soil temperatures as possible. Below 50°F, I prefer to see corn planted on a warming trend of 5-7 days. The consideration is for soil temps in the mid-40’s on a warming trend with no chance of a cold snap (cold rain/snow) within 8-24 hours for soybean and 48 hours for corn. The time-frame is due to the imbibition (critical water uptake) time-frame for corn and soybean. Soil temps for your field can be monitored by using a thermometer or checking out CropWatch soil temps at: https://cropwatch.unl.edu/soiltemperature.

Soybean Seed Treatments: From 2023-2025, growers have conducted 11 site-years of Nebraska on-farm research soybean seed treatment studies (Table 1). The studies were conducted in Seward, York, Polk, Hamilton, and Clay Counties with planting dates ranging from April 23 to May 30. The goals for the growers were to evaluate the economics and yield resulting from the seed treatments. Some of these growers also desire to move away from traditional fungicide/insecticide seed treatments due to potential impacts to pollinators, soil health, and human health. Some were also interested in any increased plant health due to early seed and microbial associations with a biological seed treatment that may have influenced a healthier rhizosphere microbiome (Berendsen, 2012). Only yield and any presence of disease was assessed. 

Results: The results of Table 1 show that in only 1 site-year (Seward-1 2025) the yield of the full company seed treatment out-yield the biological or untreated seed with which it was compared. The cost of the treatments varied by grower due to the products applied to the seed and the seeding rate. Planting dates varied on the year and location, with the locations in 2024 receiving more spring rainfall with later soybean planting. The locations in 2025 were generally planted into warm, dry soil conditions. Soybean disease was not observed as a problem in any of these on-farm research fields even though several of the locations in 2023 and 2024 had a history of white mold. Try this yourself! This is easy to do by splitting a planter or skipping planter passes with treated vs. untreated seed. Please contact me if you’re interested in trying this for on-farm research! Full article: https://go.unl.edu/uyp7.

Treatments Used:  

• Full company seed treatment (Cost: $13.72-29.00/ac)
• Untreated Seed (No Cost)
• Biological seed treatment in all the locations other than the two listed in the next bullet point (created and treated by one of the growers): blend of 2 oz PhycoTerra® ST, 1 oz Heads Up®, 1 oz N-Gage Ultra ST, 0.75 oz Bio ST VPH in 100 gal solution. In a second tank, 2 oz of Exceed Soybean inoculant was used per 100 gal only for this treatment. Cost: $9.00-$9.20/ac
• Two other biologicals used included a seed treatment by Elevate Ag (Clay 2025) (Cost: $34/ac) and a home-made compost extract seed treatment (Lancaster 2025) ($0.63/ac). 

Table 1. Eleven Site-Years of Nebraska On-Farm Research Seed Treatment Yield Data

Table 1 Note: Same letters are not statistically different at 90% confidence level. Analyzed by each individual location. 

Berendsen, Roeland L., Pieterse, Corne´M.J., and Bakker, Peter A.H.M. August 2012. The rhizosphere microbiome and plant health. Trends in Plant Science Vol. 17, No. 8, pg. 478-486.