The effects of depletion of sulfur in these soils will linger into this season. Soils that are particularly affected are loams, sandy loams and loamy sands on hilltops/ridges and slopes. Sulfur deficiency can affect any crop. The symptoms are a general leaf yellowing of newer leaves (not interveinal chlorosis), with older leaves greener.

To correct a deficiency, ammonium sulfate can be used very early in the season broadcast. An 80 lb/acre product rate should give adequate granule distribution. In solid-seeded crops, a stream-bar of ammonium thiosulfate or ammonium sulfate solution at a 10 lb S/acre rate would be adequate, but the ammonium sulfate granules may also be used. Pelletized gypsum could also be applied, but the availability in the region is low and the cost is high.

Dave Franzen

NDSU Extension Soil Specialist

701-231-8884/701-799-2565

david.franzen@ndsu.edu

For corn, some banded P is a good thing in our state (we’re north of Dekalb). About 3 gal/acre of 10-34-0 down the tube is enough to achieve a starter P effect. If there is concern about the thickness and possible ‘glugging’ into the furrow, the fertilizer can be cut with water. This spring, 10-34-0 is substantially higher in cost than 11-52-0 per pound of phosphate, so if more P is required, applying the remaining P as 11-52-0 broadcast-even in no-till- would be a better deal. Applying a liquid zinc chelate into the band with the starter fertilizer is also a good way to supply zinc in low testing soils and is cost-effective compared with large broadcast zinc sulfate rates. A 2X2 starter P band usually yields higher than in-furrow applications, but not many growers are set up with the right equipment. For those that are, application of any reasonable rate of dry or liquid fertilizer will have no ill-effect on seed germination. However, rates of N higher than 50 lb N/acre will cancel the starter P effect because roots will stay away from the high ammonia concentration for a few weeks, feeding at the fringes, until the ammonia converts to nitrate. Do not apply anhydrous ammonia in a 2X2 band.

Crops that have a strong response to starter P include canola, small grains, corn and sugarbeet. Crops with a low response to starter P are the annual legumes (pea, lentil, soybean, dry bean), and sunflower. Flax should not be fertilized with P at all. Crops with a low response can usually tolerate a small amount of fertilizer with the seed if solid-seeded, but if seeded in 15 inch rows or greater, the fertilizer needs to be broadcast. Soybeans are a crop that yields better in tests with broadcast compared to banded P.

If flax needs zinc, it could be applied with water down the furrow with the seed.

For charts on fertilizer limits with the seed, see the appropriate crop fertility circular at my web site (search for Dave Franzen NDSU, choose homepage, look for Extension Publications).

Dave Franzen

NDSU Extension Soil Specialist

david.franzen@ndsu.edu

Growers that applied late in the fall when our recommendations would suggest it was safer are more satisfied with their results than those that were early. For those who cannot recall our recommendations for fall nitrogen timing, here they are again.

1. Do not fall apply N on soils that typically flood in the spring or to soils with sandy loam or coarser textures.
2. Do not even think about applying anhydrous ammonia until October 1.
3. After October 1, check the soil temperature measured at 4 inch depth from 6-8AM. When it hits 50 F, it is practical to apply anhydrous ammonia (but not urea!)
4. A week after the date for anhydrous ammonia, growers can start applying banded urea.
5. 2 weeks after the date for anhydrous ammonia, growers can start broadcast-incorporating urea.

This past season, the date the soil temperature dropped to 50 F was about October 15. That means that banded urea application should not have begun until October 22 and broadcast urea until October 29.

I know that a great deal of fall N was applied before these dates. I know that I traveled to Bismarck for a meeting about September 20 and there was a grower applying anhydrous ammonia to a field near Jamestown. I also saw urea applicators in the field about the same time in the Valley. This was a very bad plan.

                There is nothing wrong with well-timed fall N application in North Dakota. In years of dry weather, it didn’t matter when nitrogen was applied. If the last 18 years of wetness is an indication of the beginning of a trend, I think that this winter and spring will also be wet and we will be set up for losses for N that was applied too early. Agronomy does not always mesh with convenience. Although many growers have a ‘harvest gap’ in September after small grain harvest and before soybeans/corn/sunflower, it is not the time to fall apply N. P and K can be applied during this time, but not N. Too many bad things can happen to early applied N if it is applied too early with too much fall ahead of it.

                A nitrification inhibitor should be used not to move the date of application earlier, but to protect the N-applied at a safer date from unanticipated losses from early spring wetness. N-Serve™ can be applied with anhydrous ammonia to protect N from losses due to nitrification in the fall/spring. Instinct™ is an encapsulated form of nitrapyrin (active ingredient in N-Serve), and the label I have currently lists it as a spring additive with urea or UAN. Check with your Dow-Agro Sciences rep to see if it is labeled for fall application with urea. In the spring, products with the additive DCD (examples are Super-U™ by Agrotain, Int., or Guardian™ by Conklin) will also slow nitrification. One product that is sold as a nitrification inhibitor, but does not function like one is Nutrisphere™. It is neither a nitrification inhibitor nor a urease inhibitor and should not be used as one.

Dave Franzen - Extension Soil Specialist

I have covered some of these topics in past reports, but this will serve as a ranking of my favorite to least favorite options for sidedress and topdressing corn.

For small corn, my number one favorite option is anhydrous ammonia if the soil will seal during application. Almost none of the applicators in this region have covering attachments, so the soil surface has to be mellow. If not, N will be lost and some crop burning may result. Loam soils and coarser are particularly favorable for this application. These soil textures represent around 85% of the total crop surface soil texture acres in the state.

My number two favorite options are either coulter applied UAN, or cultivator applied UAN/urea. On high clay soils, coulter applied UAN provides soil coverage of the N without having to go deep into the muck. Setting the coulter an inch or two deep should offer enough soil coverage to protect the urea in UAN from volatility.  Some growers may have soil that would support anhydrous application, but do not like to handle it from a safety risk perspective. Setting up a cultivator to apply the UAN/Urea and cover it with the cultivated soil would work fine. The cultivator application is not an option in no-till systems.

My number three favorite option for corn is dribbling/streaming UAN from a high clearance sprayer between the rows. Any rate of UAN will work if your pump and hoses will support the volume. Use of stiff hose or a bracket strengthened drop nozzle. The pressure from corn leaves as the sprayer travels through the corn will tend to lift the hoses onto the top of the corn if your drop nozzles are not substantial enough.  It may be necessary to reduce speeds, especially in taller 22 inch row corn to make sure the UAN is hitting the ground.  The UAN should land on the soil surface in a band. Half of the UAN is ammonium nitrate, with no volatility potential (practically) the other half is urea, but for some reason unknown to me the rate of urease activity is reduced when the UAN is applied in a surface band. The result is that where normally urease rate would be high nearly immediately, its activity is delayed and reduced. This application method has always worked for me both in my time in industry and as a researcher whether it was wet or dry.

The least favorite option for corn would be flying on urea by air. This is my least favorite because of the potential for leaf burn. However, given the wetness of many fields, this may be the only option for many growers. My Illinois colleague, Fabian Fernandez, reports that in his studies corn yield is not decreased with N rates of urea up to 60 lb N/acre (roughly 125 lb material per acre). Rates higher than 60 lb N/acre resulted in enough tissue burning at V8 that yields were reduced instead of increased.

In our region, rates around 40 lb N/acre should be reasonably safe if applied by air. There will be some leaf burn, so make sure the grower understands this, that it is superficial and if he sees burning consider it unimportant.

Dave Franzen - NDSU Extension Soil Specialist

 david.franzen@ndsu.edu

Today (Tuesday, July 26, 2011) I revisited the plots. They received at least one substantial rain between application and today. Although some of the striping has diminished, the plants are still struggling. With this experience, I would recommend NOT applying any sulfur or zinc to corn in wet black, high clay soils. The main problem is they are trying to grow into water and it’s not working. Any deficiency symptoms shown other than nitrogen are not as important as the drainage.  This plot is about a week away from tasseling. If it makes 100 bu/acre it will be a miracle.

                In contrast, a field in the Walcott area prompted the pest report on ‘rainbow corn’ a few weeks ago. Last week I revisited the field, fully intending to supplement the plot with sulfur and zinc. When I arrived, the corn was green (at least the higher N treatments) and over 4 feet tall. No striping, no odd colors, just normal corn. This plot missed most of the high rainfall in the region lately and the corn had the opportunity to expand its root volume and overcome its nutrient deficit on its own. As suggested in the previous crop and pest report, if the soil will dry, the condition of the corn will improve.

Dave Franzen - NDSU Extension Soil Specialist

 david.franzen@ndsu.edu

Actual measurement: For those consultants whose acreage base was substantially cut this growing season, this would be a useful thing to do for acres not cropped.

Make 1 foot square frames out of PVC, metal or something substantial and cheap.

-Throw them out into the cover crop and clip or cut the vegetation to the soil surface.

-Bag the material and keep cool until you get dry them

-After drying, weigh the biomass.

If you are really scientific about the results, send them in for N analysis.

If you understand the variability involved will probably overwhelm the plant analysis, assume that any green vegetation has about 4% N.

-Every 20.8 grams of dry matter from a square-foot equals 2,000 lb dry matter/acre, or

Each gram from a square-foot equals about 98 lb/acre dry matter

Dry matter is 4% N, so

                       (Weight dry matter/acre X 0.04 lb N/lb dry matter) = (Weight N/acre)

                According to John Moraghan’s work from about 2005 (Sugarbeet R&E Reports on the web), about 1/3 of the N you find will be available under conventional till for next year’s crop. A rule of thumb for no-till is that about 1/5 of the total will be available under no-till for next year’s crop (my estimate).

Estimating without the work:

If you have 100% ground cover of anything broadleaf that is green and it is 6 inches tall at the time of kill, you have 2,000 lb/acre dry matter. For every inch above that, add 150 lb/acre dry matter. For the N content, use 4% N again to calculate total N, then take the fraction appropriate for your tillage from above to determine roughly what might be expected for the crop. If the broadleaf cover crop is yellow (radish on low N soil), you will not receive any appreciable N credit.

For rye and most small grain cover crops, 8 inch height, 100% ground cover is about 2,000 lb/acre dry matter. If it is green, assume about 4% N. If it is yellow-green or yellow, you will not have any appreciable N credits. 

If ground cover of either broadleaf or grass is less than 100%, make the appropriate adjustment in dry matter content.

Dave Franzen - NDSU Extension Soil Specialist

Obviously with night temperatures approaching 80 degrees, we have no ‘cool of the day’. But it is cooler sometimes relative to the rest of the day. If burning the flag leaf post-anthesis showed yield reductions, we would not recommend the recipe at all. However, NDSU work has shown that even with substantial leaf burn, no yield decrease was seen. Do not tempt fate by spraying all day in a day like today when the mid-day heat index is 110 degrees F. However, if a person uses common sense and sprays very late in the evening, maybe all night, certainly in the morning between 4 AM and 9AM, any burn will be minimized. Expect some burn this year. It’s superficial and so far the potential benefits outweigh any risk.

Finally, there are still people who are using 1-2 gallons/acre of slow-release N materials to enhance protein. Careful field experiments, replicated by people with no ax to grind either way have seen no benefit to the application of low rates of these materials that only contain 3-6 lb N/acre. We have seen no foliar benefit over traditional products in N efficiencies. One study that applied one of these products at the 30 lb N/acre ‘recipe’ rate (10 gallon UAN contains 30 lb N) showed that this rate of slow-release was similar in protein to the UAN rate in the recipe. However, the cost of application of 30 lb N as a slow-release product prohibits its use. 1-2 gallon per acre is just not enough N to make a difference. It is a waste of money. Don’t do it.

Dave Franzen - NDSU Extension Soil Specialist

 david.franzen@ndsu.edu

The corn in these fields appears green from the road, but on close inspection the striping is easy to see. The corn with these symptoms was between 2 and 4 feet tall. I know that the fields where I saw these symptoms had soil tests well above 1 ppm DTPA-extract, which should be fine and most received some Zn at planting. I think what has happened is that the root system is so shallow and restricted due to the high seasonal water table, that the root mass is not large enough to explore the soil volume normal for this time of year. It’s like trying to grow corn in a pot. I have not seen these symptoms in well-fertilized medium textured soil with better drainage. I do not know if amending these fields would help. I keep thinking that it will dry out soon, and any zinc fertilizer we apply would be a waste of time. Then it rains again. This might be a year to try a foliar zinc spray just to see. One to 2 quarts of any chelated material should work if anything will. Normally, I would not suggest such a trial on a well-fertilized field.

Dave Franzen - NDSU Extension Soil Specialist

Based on this early work, and more recent work from the NDSU Carrington REC by Blaine Schatz and Greg Endres, the following is ‘The Recipe’ for post-anthesis UAN application:

1.       Wait until the wheat is nearly done flowering (some secondary or tertiary tillers may have some anthers on, but the main stems and first tillers are completely done flowering).  If the wheat berries have clear liquid in them, the timing is good. If the wheat berries start to turn milky, it is too late for enough benefit to be economic.

2.       10 gal water + 10 gal UAN (28-0-0)

3.       Apply during the cool of the day (early morning or late evening-later if plants are wilted from the heat of the day)

4.       Broadcast spray with flat fan nozzles aimed directly over the plants

This application nearly always results in at least a ½ percent protein increase. This is real wheat protein, not some absorbed ammonia that makes the analyzer put out odd results.

Do not apply low rates of slow-release N products to try to achieve similar results. These products are only effective if used at similar N rates to UAN (10 gal/acre UAN contains 30 lb N/acre). Growers will find that if used at similar N rates, the costs for using slow-release N products are prohibitive.

Some leaf burn should be expected after using the recipe. This burn is superficial and has not resulted in yield decreases in recent studies at NDSU.

Dave Franzen - NDSU Extension Soil Specialist

 david.franzen@ndsu.edu

This year we can see all the colors of the rainbow in certain stressed corn fields, if you count the dead, orange-colored lower leaves that were underwater a couple weeks ago in some fields. The multi-colored corn seen in many fields is the equivalence to our ‘black and blue’ symptoms that humans get when we are roughed up.  It is important to remember that some nutrient deficiency symptoms can cause some of these unusual corn colors, but not all odd coloring is caused from actual nutrient deficiency; often the cause is environmental.  Cold weather, wild swings in temperature/ soil moisture can all produce these symptoms. Many fields were planted when it would normally be considered too wet to plant, but I agree that we were lucky to get many fields planted at all, but that doesn’t make the soil conditions under the plant any better. Root systems are still small compared to top growth and until the roots catch up (which they will when the soil dries and the temperatures quit swinging wildly between tropical and subarctic) there will continue to be odd coloring in corn. As I write this on July 5, I have noticed a considerable improvement in just the past four days between the very strong odd colors last week compared to a movement towards traditional green summer corn fashions.  The color to watch the most for signs of improvement is yellowing.  See the article “yellow corn – nitrogen doesn’t die, it just fades away”.

Dave Franzen  - NDSU Extension Soil Specialist