Michigan State University Extension
Soils & Soil Management - Fertilizer - 06029716
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
General Fertilization of Forages. At planting, allow the legume seed to fall on top of the soil above the fertilizer band and cover no more than « inch deep with press wheels or a cultipacker. To seed bromegrass, either mix the seed with a small grain or with the fertilizer.
Boron is needed annually at the rate of 1 to 2 pounds per acre on established alfalfa growing on sandy loam, loamy sand and sand soils. Boron application for alfalfa grown on the finer-textured soils has not proven beneficial. Do not apply boron in combination seedings containing grass or small grains because it will injure these plants. Apply boron for the legume as a topdressing after the grass is well established or the grain crops harvested. Include 1 pound of zinc per acre in the topdress fertilizer when the soil pH is above 7.0 and the soil test is low in zinc.
Topdress forage legumes or legume/grass mixtures with potash in early spring while the plants are dormant or immediately after hay harvest. Potash may be topdressed in the fall on all soils except loamy sands and sands, where it will leach into the subsoil. Do not apply more than 400 lb K2O in one application.
Planting-time nitrogen is not suggested for legume seeding. Be sure to inoculate the seed before planting.
Legume Seeding without Small Grain-Adjust soil pH to 6.8 for mixtures containing alfalfa or sweet clover, and to pH 6.5 for red clover and birdsfoot trefoil. Apply and incorporate the needed lime at least six months before seeding. When more than 4 tons of lime is required, apply one-half before plowing and one-half after plowing. Incorporation by disking is suggested after each application. When sod seeding alfalfa on erosive sites, broadcast the lime without incorporation. Fertilizer recommendations for alfalfa seeding given in (Vis. 15) are for spring or summer clear seeding. Base fertilizer rates on soil test results. Up to 100 pounds of phosphate and 50 pounds of potash may be applied in direct contact with the seed. If the fertilizer is placed 1 to 1 « inches below the seed, the seeding time fertilizer may include all of the phosphorus and up to 150 pounds of potash per acre. Broadcast and incorporate fertilizer required above these amounts. This fertilizer recommendation if sufficient to establish the legume and to provide for growth until the first cutting is removed. Beyond that point, additional fertilizer is required as a topdress application.
Legume Seeding with Small Grain-Legume seedings are difficult to establish in high yielding small grains. If legumes are seeded with small grains, use the normal nitrogen rate. The fertilizer applied for small grain should be sufficient to carry the legume through the first season. Topdress fertilizer for the legume after the first cutting of hay. Follow the liming practices suggested for clear seeding legumes.
Seeding Grass Hay or Pasture-The recommendations for phosphate and potash are the same as those for 60 bushels of oats (Vis.11). When establishing grass hay or pasture, apply 30-40 pounds of nitrogen. Do not apply in direct contact with the seed more than 100 pounds of total nutrients (N +P2O5 + K2O) on coarse textured soils or 140 pounds for fine textured soils. Broadcast and incorporate additional nutrient as recommended.
Grass Pasture-Intensively grazed pastures: (Also referred to as controlled grazing.) Annually topdress with 60 pounds of nitrogen plus the phosphate and potash given in (Vis. 11).
Extensively grazed pastures: Annually topdress 100 pounds of nitrogen plus the phosphate and potash given in (Vis. 11) When the forage contains more than 50% legume, nitrogen fertilizer is not recommended.
Grass Hay - Annually topdress 100 pounds of nitrogen plus the phosphate and potash indicated by a soil test as given in (Vis. 15). As the percent legume in a field declines, the need for applied nitrogen increases. When the percent legume is less than 50 (less than 3 plants per square foot), nitrogen is recommended at 100 pounds per acre annually.
Brassicas for Forage-Brassica species for forage include rape, kale, swedes and turnips. Brassicas can be used to break up an old pasture to be planted with an improved species and/or to extend the grazing period into the late fall. They are frequently planted after small grains have been harvested. A total of 75 pounds of nitrogen is suggested to produce good yields. Follow the recommendations in (Vis. 11) for phosphate and potash. Apply up to 30 pounds of nitrogen, 50 pounds of phosphate and 50 pounds of potash in the row at planting. Additional fertilizer should be broadcast and incorporated before planting.
Grass Water Ways and Critical Areas-Grass waterways, highly erodible soil and other critical areas need good fertility levels to maintain a dense, uniform cover throughout the year. Follow the guidelines for seeding grass hay or pasture. Annually topdress 40 pounds of nitrogen per acre. To prevent runoff loss, drill in topdress fertilizer.
Mineral Soils-Topdress recommendations for phosphate and potash for grass pasture are given in (Vis. 11). Phosphate and potash recommendations for alfalfa, birdsfoot trefoil, clover and grass hay are given in (Vis. 15).
Organic Soils-Nitrogen, phosphate and potash recommendations for selected forage crops are given in (Vis. 16), (Vis. 17), (Vis. 18). Alfalfa and alfalfa-grass mixtures are not recommended for organic soils.
