ISSUE 3 May 20, 2004
PLANT NUTRITION AND COOL WEATHER
Ideal weather for most of our crops has only been seen a day or two this spring so far. It has either been too cold, too hot, too wet or too dry. Cool weather slows germination and growth. Young plants have poor root systems and nutrient uptake is slow. Growers are likely to see early advantages due to starter band fertilizer application in most crops this season. Nutrient deficiency symptoms are likely in many crops due to the cool temperatures. Corn may turn purple and small grains will look anemic. Other crops may be slow to emerge. Flax will turn chlorotic in carbonate rich soils due to iron chlorosis. These symptoms are more environmental than nutritional for the most part. As soil temperatures increase, the symptoms will quickly disappear. A spot check of soil or plants for a suspected nutrient problem may help to alleviate fears of nutritional problems.
ANHYDROUS APPLICATION AT SEEDING
Preplant anhydrous application should be conducted at a slight angle to the intended direction of seeding. By the book, the waiting period between ammonia application and seeding is 5-7 days, depending on the book. However, I have witnessed crop damage from a fall ammonia application to spring small grains, so I have pretty much thrown the book away. If a grower applies ammonia prior to seeding in the same direction as the seeder will travel, waiting the full 7 days is a good plan. The preferred way would be to apply the anhydrous ammonia at some angle to the intended row direction and seed soon afterward. Some plants that are seeded above the anhydrous band will probably not emerge, but at least there will be no large gaps between plants.
MICRONUTRIENTS FOR WHEAT
Topdress micronutrient applications for small grains in North Dakota were researched as far back as forty years ago. I recently came across a study by Armand Bauer at NDSU who investigated application of foliar zinc, copper, boron, iron, and manganese on barley in 1964. There were no differences in yield between the application of micronutrients and the check. This has been the history of foliar applications to small grains in North Dakota through the years. Even in the studies I conducted with copper a few years ago on responsive sites, the foliar treatment was not effective in correcting a copper problem. Copper is the only micronutrient that I have seen a response to in this state, and even then the response was confined to a particular sandy, low organic matter soil.
NDSU Extension Soil Specialist