Ranchers should expect a delay in grass development this spring due to drought conditions last fall, according to North Dakota State University Extension livestock specialists.
All cool-season grasses, which are the dominant grasses in North Dakota, initiate growth from a tiller that was established the previous growing season. However, drought stress during the fall of 2020 caused tillers to die, setting back plant development this spring.
“North Dakota’s drought-stressed pastures will require special care this spring to help them recover from the fall drought,” says Miranda Meehan, Extension livestock environmental stewardship specialist.
These pastures must be given adequate time to recover. Grazing too early in the spring can result in decreased total forage production for the entire grazing season.
Decreased forage production is a concern because North Dakota experienced widespread drought in the fall of 2020 and 100% of the state is in a drought. As a result, producers should expect at least a 20% to 25% decrease in forage production in 2021.
“This reduction will be even greater if pastures are grazed too early, reducing leaf area and the plants’ ability to capture sunlight,” says Extension rangeland management specialist Kevin Sedivec. “Grazing too early will reduce plant vigor, thin existing stands, lower total forage production, and increase disease, insect and weed infestations. Pastures and range damaged by grazing too early may take several years of deferment or even rest before the stand regains productivity.”
A loss of herbage production due to grazing prior to grazing readiness will reduce the recommended stocking rate and/or animal performance, the specialists add. Grazing readiness for most domesticated pasture is at the three-leaf stage, whereas grazing readiness for most native range grasses is the 3 1/2-leaf stage.
In North Dakota, the recommended time to begin grazing native range is mid to late May, which coincides with grazing readiness in most cool-season native range grasses. Domesticated grass pastures, such as crested wheatgrass and smooth brome, reach grazing readiness two to four weeks earlier than native range, permitting grazing in late April to early May.
“Following the 2017 drought, we observed a three-week delay in grazing readiness of smooth brome and up to a four-week delay in grazing readiness of western wheatgrass,” Meehan says. “This year, we will likely see a delay in grazing readiness, especially in pastures that were overgrazed and did not receive adequate time to recover.”
Strategies to avoid grazing native range prior to grazing readiness include:
- Grazing domesticated grass pastures, such as crested wheatgrass and smooth brome, in May
- Providing supplemental forage to livestock on domesticated pasture or hay land
- Using winter annuals that were established last fall for early spring grazing or hay
- Continuing dry lot feeding in May
“It is important to allow adequate recovery to native pastures,” Sedivec says. “For our native grasses, grazing before grass has reached the 3 1/2-leaf stage can result in a loss of 45% to 60% of the potential forage production potential.”
Producers should have a grazing management plan in place that includes strategies and trigger dates for making drought management-related decisions.
Implementing the plan in a timely manner is important because 80% of the grass growth on rangeland in this region is dictated by May and June precipitation. Drought conditions during this period will reduce the amount of grass available on pasture and rangeland for the duration of the grazing season, as well as hay land.
“Actively managing your grazing resources to prevent overgrazing will reduce the length of time it takes to recover from drought and improve the long-term sustainability of your operations,” Meehan says.
Source : ndsu.edu