By Blake Jackson
Cool-season forage grasses require ample nitrogen in spring for optimal growth and protein content. While legumes like clover and alfalfa naturally supply nitrogen, supplemental applications are necessary when these are absent.
Spring nitrogen application rates vary by region and soil type. Recommendations typically align with pounds of nitrogen needed per ton of forage produced.
For instance, if aiming for two tons of hay per acre in the second cut, 100 pounds of nitrogen per acre is required post-first harvest.
First-cut hay production in Pennsylvania can be challenging due to weather and volume. To mitigate issues, consider applying 30-50 pounds of nitrogen per acre in spring, rather than 50-100 pounds.
The optimal time for nitrogen application, known as "green-up," occurs when plants break dormancy and begin active growth. This usually happens between mid-March and mid-April.
Growing degree days (GDD) can refine this timing; nitrogen application can begin around 200 GDD (base 32). Early applications boost forage tonnage and protein, while later applications primarily enhance protein content.
For pastures, stagger nitrogen applications to avoid simultaneous forage readiness. Apply nitrogen in seven-to-ten-day increments, aligning with grazing management.
Nitrogen's mobility in soil necessitates careful management. Controlled-release products or split applications are crucial.
Controlled-release nitrogen, with a polymer coating, releases nutrients over 50-80 days, ideal for situations where in-season applications are difficult. Combine these products with urea or ammonium sulfate for immediate nitrogen availability.
Split applications using granular or liquid urea or ammonium sulfate involve applications before each cutting. Apply nitrogen in spring around 200 GDD (base 32) and after the first and second cuttings for increased production.
For detailed information on nitrogen management and split applications, consult resources like "Soil Fertility Management for Forage Crops: Maintenance." These strategies ensure adequate nitrogen supply, maximizing forage production and quality for livestock needs.
Photo Credit: gettyimages-mvburling
Categories: Pennsylvania, Crops, Hay & Forage