Michigan State University Extension
Soils & Soil Management - Fertilizer - 06029709
07/10/97
Fertilizer Recommendations for Field Crops in Michigan Extension Bulletin E-550A, March 1992
D. R. Christenson, D. D. Warncke, M. L. Vitosh, L. W. Jacobs and J. G. Dahl, Department of Crop and Soil Sciences
Micronutrient fertilizer recommendations are based on soil pH, soil test and crop responsiveness for each. The recommended rates are given in (Vis. 3) (Vis. 4) (Vis. 5) (Vis. 6) for highly responsive crops. A brief discussion of each is given.
Manganese (Mn)-Manganese deficiency may occur on oats, field beans, potatoes, soybeans, Sudan grass, sugar beets and wheat. In extreme cases, barley may respond to applied manganese. Manganese availability decreases as soil pH increases. Liming can, therefore, induce a manganese deficiency on soils with marginally available Mn soil test values. Flooding or fumigation of soils temporarily increases Mn availability.
Suitable carriers are manganese sulfate, partially acidulated manganese oxides and finely ground manganous oxide. Manganese chelates are not recommended for organic soils and have not been shown to be more effective than manganese sulfate on mineral soils. Apply chelates to mineral soils at the rate of nutrient given in (Vis. 3). Neither granular manganese oxide nor any of the manganic forms are acceptable manganese materials. Finely ground manganous oxide that has been regranulated may be reasonably effective, however. Manganese is usually fixed very readily in soil, so broadcast application is not recommended. Apply manganese to foliage if band application is not possible or does not completely alleviate the deficiency. Apply 1 to 2 pounds of Mn per acre and repeat the application if deficiency symptoms develop on new growth in 7 to 10 days.
MINERAL SOILS. A manganese deficiency is most likely to occur on dark-colored surface soils in lake bed or glacial outwash areas with a pH above 6.5. (Vis. 3) provides recommendations for rates of manganese to apply in a band with starter fertilizer for responsive crops grown on mineral soils.
ORGANIC SOILS. Manganese deficiency is most likely to occur on organic soils with a pH of 5.8 or above. See the discussion above about using chelated sources of manganese for organic soils.
(Vis. 4) provides general guidelines for rates of manganese to apply in a band with starter fertilizer for responsive crops grown on organic soils.
Boron (B)-Boron recommendations are based on crop response and not on soil tests. Annual applications are essential for boron-responsive crops because it occurs as a water-soluble anion subject to leaching. Never apply boron in the starter fertilizer for field beans, soybeans, corn or small grains since they are sensitive to boron injury. Applying higher than recommended rates may result in residual boron carryover which could injure sensitive crops. Recent research shows that applied boron is not needed for sugar beet production in Michigan. See Research Report 518 listed in the references for further information.
Use 1 to 2 pounds of boron per acre for alfalfa grown on sandy loam, loamy sand and sand soils.
Zinc (Zn)-Extractable (0.1 N HCl) Zn values used in conjunction with soil pH, provides a very good indicator for availability of zinc to plants. Zinc availability decreases as pH increases. Therefore, more Zn is recommended at higher pH levels for a given zinc soil test level. Finely ground zinc oxide that has been regranulated may be reasonably effective, but granular forms of zinc oxide are not effective. Band applications are suggested, but a broadcast application of 10 pounds or more of Zn per acre is effective. Annual applications of zinc will build up available zinc levels and gradually eliminate the need for supplemental zinc. Foliar sprays of 0.5 pounds of zinc as zinc sulfate per acre will correct zinc deficiencies of growing crops.
MINERAL SOILS. Zinc maybe needed for field beans and corn
grown on alkaline mineral soils of the lake-bed region of
eastern Michigan depending on the soil test level of the
soil. Deficiency is especially noted on crops growing on
spoil-banks, over tile lines where calcareous subsoil is
mixed in, or where high rates of phosphorus are applied.
Recommended rates based on soil tests are given in (Vis. 5)
These rates are for inorganic salts of zinc. Use
one-fifth of this rate for chelates.
ORGANIC SOILS. Zinc deficiency is more likely to occur on nearly neutral or alkaline organic soils. Field beans and corn are most often affected under Michigan conditions. Recommended rates based on soil tests are given in (Vis. 5)
Copper (Cu)-Field crops grown on mineral soils are not known to respond to applied copper.
However, acid peaty soils are usually low in copper and field crops will respond to applications of the nutrient. The carriers used are usually the sulfate or oxide forms. Copper applied to organic soil is not easily leached and contributes to buildup of available soil copper. For this reason, no further copper fertilization is needed if a total of 20 pounds per acre has been applied for low or medium responsive crops and 40 pounds per acre for high responsive crops, or if the copper soil test level exceeds 20 ppm.
Oats, wheat, sorghum and Sudan grass are highly responsive to applied copper. The medium responsive field crops are clover, sugar beets and corn. Pastures, rye, field beans, soybeans and potatoes are rated as "low responsive."
(Vis. 6) gives the recommendations based on responsive ratings for field crops grown on organic soils.
