Michigan State University Extension
Soils & Soil Management - Fertilizer - 06039723
07/10/97
Tri-state Fertilizer Recommendations for Corn, Soybeans, Wheat and Alfalfa Extension Bulletin E-2567 (New), July 1995
M.L. Vitosh, Michigan State University; J.W. Johnson, The Ohio State University; D.B. Mengel, Purdue University; Co-editors
(Vis. 27, Vis. 28, Vis. 29, Vis. 30) give recommended rates of soil-applied inorganic sources of micronutrients based on soil type, soil test and pH. These rates are recommended only for the responsive crops listed in (Vis. 24). The micronutrient soil tests recommended for use in Michigan, Ohio and Indiana are 0.1 N HCl for Mn and Zn and 1.0 N HCl for Cu using a 1 to 10 soil-to-extractant ratio. Micronutrient availability in both mineral and organic soils is highly regulated by soil pH. The higher the soil pH, the higher the soil test should be before a deficiency is eliminated. The higher the soil pH and the lower the soil test, the more micronutrient fertilizer is needed to correct a deficiency. Copper deficiency in Michigan, Ohio and Indiana has been observed only on black sands and organic soils. Because of the extreme Mn and Cu deficiency problems and often excess N mineralization in organic soils, wheat and oat plantings are not recommended on these soils.
Boron recommendations for Michigan, Ohio and Indiana are not based on any soil test--they are based on soil type and the responsiveness of the crop. Boron is recommended annually at a rate of 1 to 2 pounds per acre broadcast applied on established alfalfa and clover grown on sandy soils. Boron applications on fine-textured high clay soils have not proven to be beneficial.
Molybdenum deficiency of soybeans has been found on certain acid soils in Indiana and Ohio. Most molybdenum deficiencies can be corrected by liming soils to the proper soil pH range. The recommended molybdenum fertilization procedure is to use « ounce of sodium molybdate per bushel of seed as a planter box treatment or 2 ounces of sodium molybdate per acre in 30 gallons of water as a foliar spray. Extreme care should be used when applying molybdenum because 10 ppm of Mo in forage may be toxic to ruminant animals.
(Vis. 31) gives foliar micronutrient recommendations for responsive crops listed in (Vis. 24). Foliar rates of suggested sources should be based on the size of the plant--use higher rates for larger plants and lower rates with smaller plants. Use 20 to 30 gallons of water for sufficient coverage of the foliage to ensure good uptake of the micronutrient. When foliar sprays of chelates are used, follow the labeled rate--using too much can cause foliar injury and reduced uptake. At reduced rates, chelate foliar sprays are usually less effective than the suggested inorganic sources.
New 5:95-LJ-Mb, 12.5M, $1.00, for sale only (Field Crops, Fertilization and Liming) File 22.04
