ISSUE 1 May 13, 2010
PLANNING FOR WHEAT PROTEIN
Wheat protein is a product of yield and available N. If the wheat has enough N to support yield, or barely enough to support yield, protein will be low. If available N exceeds what is needed to reach yields supported by available water and seasonal heat, then protein will at least be at industry standard 14%. The new spring wheat and durum N recommendations have been online since Dec 1, 2009 and are available to growers and their consultants. By following these new recommendations, the risk of low protein will be minimized. N recommendations are based on past yield history and not a guess as to how this season will turn out. The new recommendations also prompt growers to review past cropping practices, excessive straw from last year, and protein characteristics of varieties. By considering these factors and then adjusting rates accordingly, better rates of N can be used.
If the season progresses very well, with cool daytime temperatures at critical growth periods as tillering and early jointing and then again at pollination, a grower might choose to supplement the pre-plant/at-planting N application with a post-anthesis N application. This post-anthesis N application has been well researched in the world and in North Dakota. The "recipe" is to apply 30 lb N (10 gal/acre) 28-0-0 liquid, mixed half and half with water, and applied broadcast over the wheat at the watery-ripe berry post-anthesis stage of growth during the cool of the day. If the berry water begins to turn milky, it is too late for protein increase. Do not apply before or during flowering. Use of low rates of slow-release N products for this purpose is not recommended, since research at low rates has resulted in little benefit to wheat protein. If these products were applied at N rates similar to 28-0-0, they would result in less leaf burn, but will have similar protein increases to 28-0-0 application; however, these higher rates would be very expensive. Application of 30 lb N/acre has resulted in a protein increase of ½ - 1% protein, with ½ % being more commonly recorded.
WHY DID EVERYTHING OVERWINTER THIS YEAR?
Many people have noted that weeds, winter wheat and small critters all overwintered better this year than they could ever remember. Usually heavy snow, wind and cold temperatures result in lower winter annual weed, winter wheat and critter survival, but not this year. I had an unusual occasion to venture out into fields in late February to gather soil for land judging trainings in March. I thought that once I traveled west of Fargo, I could find bare soil areas and with a pick and shovel, fill a few buckets with soil and be on my way. I soon found that from Fargo to Williston, the fields were blanketed with 2-3 feet of snow everywhere. When I stopped near Amenia, Valley City and Cooperstown to gather the soil textures I needed, I had to chop through 2 to 3 feet of snow to reach the soil surface. As I chopped into the snow with a stout shovel, I noticed that the snow was relatively hard and not fluffy, and about a foot above the soil, there was a particularly hard layer. I guess that this is the layer affected by the freezing rain during our January thaw period. Below this layer was a layer of large-granular/clustered snow with significant air pockets. Above the soil directly was an air gap of an inch to two inches and the snow was not cemented to the soil as in other years. The soil at the surface was fluffy and appeared freeze-dried for an inch or two in depth. Below this depth, the soil was frozen and I had to use my pick, but the air-gap above the soil was unique to previous winter expeditions I have had. I think that seeing this air-gap over the soil surface and the loose and large-granular quality of the snow below the iced layer at several locations during my soil mining expeditions is the reason for the higher degree of over-wintering this spring. Air is a great insulator, and there certainly was plenty of air under that blanket of snow.
MICRONUTRIENTS AND HERBICIDES
There have been several questions this winter regarding the combination of micronutrients and herbicide applications to save trips over the field this spring. Some of the support for this practice comes from northern Indiana, Michigan and northwest Ohio, where the addition of manganese to glyphosate helped to reduce "yellow flash" in soybean. People somehow think this will help here also. In the region where this has been more successful, crops are commonly deficient in manganese. The Michigan crop fertilizer recommendation circular has a whole section on manganese, since deficiencies have been seen since crops were grown in that state. Manganese is a very common micronutrient problem in that region. However, in North Dakota manganese deficiency has never been seen outside a greenhouse. My colleagues that have worked with micronutrients over the years have not seen the problem, and crops do not response positively to manganese application. Our soybeans will not respond to manganese the way they do in the Indiana, Michigan, Ohio region.
We have crops like dry edible bean and corn that may be deficient in zinc. Even then, application of zinc with herbicides would not be a good plan. In North Dakota research, herbicide efficacy can be reduced when metal ions are added to the mix, and herbicides may become more phytotoxic to crops when metals are added. It is always the best practice to apply micronutrients when needed and herbicides in separate applications. Application of zinc at or before seeding is the best way of applying the micronutrient and saving a field trip later.
NDSU Extension Soil Specialist