Alexander has seen a significant decrease of rainfall and grass growth since the drought hit in 2010. "In March, I had a rain of two inches," he says. "It had been 869 days since I had a two-inch rainfall." Before 2010, there was about 2,500 to 3,000 pounds of forage per acre of native prairie. "For the last three years, we're producing half, about 1,500 to 1,700 pounds per acre." The amount of residual herbage is important for the next year, although Alexander's renters take in some cattle for winter grazing. "I like to end up with somewhere around 800 pounds of forage an acre going into the winter," he says. "500 would be the lowest I could possibly go."
Using rainfall data to plan ahead
In his area, 50% of the forage is typically produced by June 15. "Historically, this area is supposed to get 18 to 22 inches of rain a year," Alexander says. "Based on the last three years, that's where we're moving back toward." So, decisions would be made based on this rainfall data over several years. "As our rainfall patterns move, we're going to have to move our stocking rate down," he explains. "Over three years, if you're only getting half of your rainfall during the growing season, that's what your stocking rate is going to have to be. If you're only getting half your rain, you're still only getting half your grass."
Resting periods, grazing periods and stocking rates are not based on time, but rainfall and how much the grass has actually recovered, although some forage has had as much as 400 days of rest. "You can rest, but has the forage recovered?" Alexander asks. Resting periods vary. "On some pastures, I've pushed it out to 75 days of rest," he says. "60 days is a good number to shoot for, but that's for me and my personal experience." Grazing periods also vary. "We've got some paddocks that are 40 acres that they graze in a day, and some that are 200 acres that they graze in four to five days."