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Competency Area 6: Nutrient Management and Planning

PO 61. Describe and understand practices that reduce the risk of nitrate leaching. (Examples of practices based on NY guidelines)

  • Unless the NY P Index identifies the need for P-based fertility management, manure and fertilizer application rates should be based on Cornell guidelines for meeting crop N needs.
  • For corn, pre-plant (other than starter fertilizer) and early post-plant broadcast applications of commercial N without the use of nitrification inhibitors are not recommended.
  • Sidedress applications should be made after the corn has at least four true leaves.
  • For row and cereal crops, including corn, maintain starter fertilizer N rates below 50 lb/acre actual N under normal conditions.
  • Manure and fertilizer applications should be adjusted based on information provided in "Nitrogen Recommendations for Field Crops in New York."
  • Evaluate the need for sidedress N applications based on PSNT or other soil nitrogen tests.
  • Sod crops should not be incorporated in the fall.  Chemical sod killing may be carried out when the soil temperature at the 4-inch depth is approaching 45°F.
  • Minimize fall and/or winter manure application on good grass and/or legume sod fields that are to be rotated the following spring.
  • Appropriate ammonia conservation is encouraged.  Losses can either be reduced by immediately incorporating manure, or eliminated by directly injecting manure as a sidedress application to growing crops.
  • Plant winter hardy cover crops whenever possible, especially when fall manure is applied (e.g. rye, winter wheat, or interseed ryegrass in the summer).
  • Manure may be applied in the fall where there is a growing crop.  Judicious amounts of manure can be applied to or in conjunction with perennial crops or winter hardy cover crops.  Applications should generally not exceed 50 lb/acre of first year available N, or 50% of the expected N needs of next year's crop.
  • Frost incorporation/injection is acceptable when soil conditions are suitable, but winter applications should be made in accordance with the NY Phosphorus Index.
  • Manure N application on legumes is acceptable to satisfy agronomic requirements when legumes represent less than 50% of the stand.  When legumes represent more than 50% of the stand, manure application should be limited to no more than 150 lb available N/acre.
  • Do not spread manure less than 100 ft from wellheads and springs.