Encouraging grass recovery
By David G. Hallauer
Meadowlark District Extension Agent
With any luck, you'll have received some beneficial rain by the time you read this. To understand our recovery potential for grass, we need to know how grass grows. We put a lot of energy (from roots) into vegetative growth then grew enough top growth to replenish root reserves. Harvest came, immediately followed by higher temperatures and reduced moisture.
If we had decent growth early in the season, we may well have energy enough in the root system to kick off fall growth. That assumes we put any reserves back in the spring--and we didn't reduce those reserves by regrowth after harvest. In other words, we've sat dormant all this time awaiting conditions that will allow regrowth to occur (moisture/temperatures).
When regrowth begins, we'll pull stored nutrients from the roots, temporarily weakening the root system. Eventually, new leaves will begin to harvest sunlight and replace those nutrients for the root system.
Forage supply is short, and many are tempted to graze any little bit they can immediately. Reconsider doing this. If we immediately remove new green tissue, we leave nothing to harvest sunlight for photosynthesis that could replenish roots. We need to increase root nutrient levels for winter survival. Otherwise, we risk plants going in to winter in a weakened state. As UNL Extension Forage Specialist Bruce Anderson says: "Some may die. And those that survive to next spring will grow very slowly until they have recovered from the multiple stresses of drought and untimely grazing."
If you can afford to sacrifice pasture production--at any level, and you have to have immediate grazing, you might go ahead and graze. If you cannot--and most of you plan to remain in/return to the cattle/hay business next year--you need that grass next summer, too, and you may choose to hold off on any grazing until next year, giving that forage stand the best opportunity to survive/respond.
Here are a couple of rules of thumb to consider: 1) we need 4" to 5" of regrowth on our cool-season grasses in the month prior to the first killing freeze (typically on/around Oct. 15) to replenish root reserves for winter and 2) some literature would suggest allowing forage recovery to a 6" to 8" height before ever considering initiation of grazing.
One last caution: Watch stands closely. Those with invasive weeds or that don't tiller this fall or with low fertility levels will be at a greater risk of survival. If fertility has been an issue in the past, some small rate of nitrogen with phosphorous this fall may be of benefit to encourage tillering.