By Gary Sliworsky, Ag rep, Emo
Soil fertility plays a major role in fall pasture growth, the over-wintering of the plants, and the following spring’s production.
Fall is a good time of year to help a pasture that is struggling from being over-grazed, stressed by poor growing conditions, or a combination of both.
Nitrogen is the key, but phosphorous and potash are important additions to getting pastures back into productivity.
Grass pastures, particularly those with a large percentage of fescues, will respond to nitrogen with good fall growth if moisture is available. Use 50-75 pounds of nitrogen per acre.
A return of 20-30 pounds of dry matter per pound of nitrogen applied per acre is possible with tall fescue, orchardgrass, bromegrass, perennial ryegrasses, and reed canarygrass.
How large the response will be depends on how soon the nitrogen is applied, the current condition of the field, the amount of moisture available, and when the killing frosts start.
By fertilizing, a producer can get fresh fall feed and better weed control. Early-fall nitrogen applications, for example, stimulate fall tillering in grasses.
The result is a stronger sod with fewer bare spots—and fewer sites for weed establishment.
Fall applications of nitrogen are important to help grasses over-winter and grow quickly in the following spring. Grasses fertilized in the fall accumulate more nitrogenous food reserves, which are used to support life in the winter and to start growth in the spring.
An extra two weeks of productive pasture in the spring can be obtained from nitrogen applied from September to late October.
If winter feed stocks are tight, that extra two weeks is a major benefit!
The nitrogen you apply in the fall will not affect the legume content in your pastures.
Phosphorous and potash applied in the fall also will improve your pastures in the year after a drought. Surviving plants, particularly the legumes, will go into the winter in better shape and therefore have more chance of surviving the winter stresses.
In addition, the nutrient status of the soil will be enhanced, which will help new forage plants establish next spring.
Keep this in mind if you are planning to do any over-seeding this fall or frost-seeding this winter (the best way to determine phosphorous and potash requirements are with a soil test).
The fertility management you choose to follow in the fall will have a major impact on the next year’s grazing season.
Even if there is another dry year, the pastures will be ready to provide as much feed as possible.