As I write this article there is 5 inches of snow on the ground which makes it hard to realize that now is the time to start spreading fertilizer on hay and pasture ground because it is February 18th. Timing of nitrogen fertilization on our coolseason grass fields can make a big difference on yield. A good economic management practice would be to apply expensive fertilizer correctly in order to get the most out of your fertilizer (your money).
Coolseason grasses (fescue, orchardgrass, and bluegrass) roots develop in soil temperatures from 32⁰F to 80⁰F. Optimum soil temperatures for root development is 50⁰F to 65⁰F. Optimum soil temperature for shoot growth is 60⁰F to 75⁰F. Kentucky weather mesonet data show that our soil temperatures are around 50⁰F by mid-March and is 60⁰F by end of March. Therefore, it only makes since to get the most from your nitrogen fertilizer is to apply it when the grass can utilize it the most. Apply in nitrogen in late February and early March give grass a boost in root and shoot development. Research shows that the recommended amount of applied in early March will yield 2.5 times more grass by May then non fertilized grass. Also, a larger percent of that grass will be available earlier which means grazing can begin up to two weeks earlier in fields properly fertilized in early March.
If a farmer wants to manage strictly for grass health and production, then split applications of fertilizer is recommended. Applying nitrogen in early spring, late spring and early fall would increase yield due to optimizing plant shoot and root development. Soil testing is a must and maintaining proper phosphorus and potassium levels along with a soil pH around 6.4 must be part of the fertilizer program as well.
In conclusion, fertilizer cost is one of the biggest expenses of raising any crop even gras pasture. Like any business, in order to be the most successful and profitable efficient spending is a must. Research shows to get the most from nitrogen fertilizer applied to coolseason grasses it needs to be available to the plants in the month of March for our area. Therefore, fertilizer should be applied to our grass hay and pasture field in early March to maximize good quality yields.
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