Even though we are still in the month of February, it is not too early to start thinking about the 2010 cropping season. One of the major expenses for modern crop production is fertilizer. During the fall of 2008 we saw fertilizer prices climb to all-time highs. We have seen these record high prices fall some what. The fall of 2009 proved to be a difficult time to apply fertilizer for next years crop. However, with tight bottom lines, farmers have had to make some tough decisions with fertilizer purchases. One item that should not be ignored is the use of micronutrients.
Fertilizer management in Minnesota concerns itself mainly with the big three of fertilizer management Nitrogen, Phosphorous and Potassium. These nutrients work to improve both crop yield and quality. There are other soil nutrients that have little if any effect on production and therefore can be classified as micronutrients. However, we do know, through research, that there are some micronutrients that must be present for profitable crop production. So it is important to review and summarize some of these elements to determine which ones to include in our overall soil nutrient package.
ZINC: For Minnesota crop producers, this is the most important micronutrient of all. When soil levels are low, both corn and edible beans will respond. For best results we need to conduct a soil test and follow the recommendations. When we look at soil test results, zinc levels will be reported in parts per million (ppm). When soil test levels of zinc are below .75 ppm, we need to be supplying supplemental zinc. Current prices show that zinc applied in the dry form was about $1.50 per pound. Liquid zinc will be higher. The exact role of zinc in crop production is not clearly defined but we do know that it is necessary for the functioning of several enzymes and when zinc is deficient, we will see abnormal growth and development.
MANGANESE: This element is also essential for many enzyme reactions in plants with no specific, well defined function. However, the use of additional manganese has not increased crop production in Minnesota. So we do recommend additional applications of manganese in fertilizer applications.
IRON: Many soybean growers are familiar with Iron Deficiency Chlorosis (IDC) in soybeans. However, there is no deficiency of iron in Minnesota soils. Under certain soil conditions, iron is not available to the plant and cannot be used by the soybean plant to produce chlorophyll. Research continues to look for methods to control this problem.
BORON: While there is no universal agreement on the role of boron in corn and soybean production, we do know that it is an essential element especially in alfalfa production. A top-dress application of 2 4 pounds per acre has increased alfalfa yields when soil test results show that there is a need. However, we need to be cautious as over-application can reduce yields.
COPPER: Small grains such as oats and wheat grown on organic soils have shown a positive response to the application of this micronutrient. However, outside of this, there is no need for additional copper in a fertilizer program.
CHLORIDE: Although the specific function of this element in plants is unknown, we do know that chloride can help small grains resist disease pressure. However, this micronutrient is not needed if we have applied 0-0-60 (NaCl) in the past. Chloride, the Cl portion of 0-0-60 is a salt that is only needed in minute amounts.
Recently there have been some sales promotions which states that micronutrients coated or sprayed on other fertilizer granules will improve crop yields. These claims are not substantiated by research and should be avoided.
Dates to remember:
"Putting a $ Value on Manure Workshop": Thursday, March 25th Lafayette Community Center 9:30 am Call the Nicollet County Extension Office at 507-934-0360 to RSVP.