Top Products For Sidedressing, Topdressing

Applying nitrogen soon will help corn, sunflowers, sugarbeets and wheat recover yield potential.

Published on: Jun 18, 2013

If you have had lots of rain this spring, many of your fields may have lost nitrogen and the crops may need to be topdressed or sidedressed soon.

Dave Franzen, North Dakota State University Extension soils specialist, says his top product choices for sidedressing and topdressing are:

For topdress N in wheat and other solid-seeded crops
No 1 choice -- stream-bar UAN (28-0-0). "It is half ammonium nitrate, so there is almost no volatility. A concentrated band on the soil surface as is achieved when UAN is applied in a stream reduces the rate of urease activity. I do not know why this happens, but data support that it does."

No. 2 choice -- urea with Agrotain/NBPT. "With the urease inhibitor, you have 10 days of relative safety from urease activity. After that, the effects diminish rapidly. However, with the frequency of rains in the last 30 days, the chances of significant loss before crop uptake will probably be low if history predicts the future."

Sidedressing and topdressing may be needed to replace nitrogen lost caused by heavy rains.
Sidedressing and topdressing may be needed to replace nitrogen lost caused by heavy rains.

For side-dress corn, sunflower and other row crop
No 1 choice -- anhydrous ammonia in medium to sandier texture soil, coulter UAN in high clay soils (Beardens and higher clays including Fargo, Hegne and their brothers and sisters). "With a coulter, the depth of application can be 1-2 inches compared to 5-6 inches with anhydrous ammonia. With a coulter, the chance of entering the muck underneath the relatively drier soil is low, so application can proceed in most soil conditions. With both anhydrous ammonia and coulter UAN, the row crop can be fertilized every other row. There is no particular need to set up every row. Row crops do not behave like a tree. If you fertilize one side of a tree, one side will be healthier than the other. If you fertilize one side of a row crop, the nutrients are distributed evenly to all parts of the plant."

No. 2 choice -- streaming UAN between the rows. "Most stream bars have some wiggle, so set up for between every row. Avoid applying the stream on top of the plants as burn will surely occur unless you are thunderstormed out of the field."

No. 3 choice -- broadcast urea over the top. "In corn, limit the N to 100 lb/acre of urea (about 46 lb N/acre). Research from Illinois suggests that up to 60 lb N, the benefits of over-the-top urea application out weight damage to corn. Over 60 lb N/acre, the damage outweighs the benefits. Apply the urea with Agrotain/NBPT."

Source: NDSU Crop and Pest Report