Hay and Pastures
Is it too late to fertilize my forages? - John Jennings
With the recent rains, producers are asking about fertilizing fields for a last hay cutting. For warm season forages such as bermudagrass and bahiagrass we are at the end of the season. The UA Fertilizer Recommendations Manual states that warm season forages should not be fertilized after September 1. Realistically, on drought stressed forages, the cutoff date should be earlier than that. The reasoning is that even after rain, drought stressed forages make take a week to even show greenup, another week to accumulate any leaf area, leaving only about a week to produce any significant amount of forage before short days and cooler nights in late September start shutting down warm season grass growth. When night temperatures drop into the 50’s warm season grass growth stalls and it could take a few days to restart. When night temps drop into the 40’s growth stops and by that time of year there are not enough warm hours in a day to restart the engine.
Arkansas research on stockpiling bermudagrass shows that at Batesville and Fayetteville, delaying N application from August 1 to September 1 reduced forage dry matter yield from 60-80%. That would apply for hay production as well. In south Arkansas that date could be moved from August 1 to August 15. Each day closer to September reduces warm season grass yield potential and viability of making late fertilizer applications economical.
However, timing for fertilizing fescue is right now. Our research on fertilizer timing for fall fescue growth, either for fall pasture or stockpiled winter pasture, showed that early September is the optimum time to apply nitrogen fertilizer. Waiting until early to mid-October produced no more dry matter yield than the unfertilized control.
So if producers need fall forage, fescue fertilization is a good option, and it’s too late to expect a good response from fertilizing warm-season forages. Other options for fall forage include planting oats or brassicas in early September. Delays past mid September on planting brassicas essentially produce no grazeable forage in the fall. Millets such as pearl millet, browntop, and japanese millet, can produce some forage if planted the first week of September. Ryegrass is a poor fall forage producer, but can be mixed with winter or summer annual forages to produce spring grazing.
