By Jerry Volesky, Range Scientist
2020 Weather and Forage Production at GSL
Total precipitation during 2020 at the Gudmundsen Sandhills Lab (GSL) was nearly 2.5 inches below the long-term average (Table 1. Drought Monitor for April 6,2021)
In 2020, overall upland range forage production at GSL was 8% below the long-term average (Table 2). Production from cool-season grasses and sedges was considerably higher than average, while warm-season grass production was lower. Above average May precipitation likely contributed to that cool-season production and a relatively dry June reduced warm-season growth. Although July precipitation was above average, distribution of that rain was not favorable for increased warm-season growth.
2021 Late Spring and Summer Outlook
Late summer and fall of 2020 had limited precipitation across much of the state of Nebraska which led depleted soil moisture conditions going into winter. However, heavy rainfall and/or snow during March significantly helped recharge soil moisture. The US Drought Monitor in early April still does show much of central and western Nebraska as abnormally dry to a pocket of severe drought in southwest part of the state (Figure 1).
The NOAA long-term precipitation outlook for May, June, and July 2021 does suggest an enhanced probability of drier than normal condition across Nebraska (Figure 2). This 3-month period is most critical for both cool- and warm-season pasture growth.
Figure 2. NOAA long-term precipitation probability outlook for May, June and July 2021
2021 Grazing Plans
While we always hope for the perfect amount of rain for the growing season, being prepared and having a plan for droughty conditions can reduce the impact. Within these plans, options for a possible drought are essential. A drought plan can have varying levels of detail and complexity and can be customized to fit the specific needs of your operation. Key considerations should include projected cattle numbers (or stocking rates), turnout dates, the possibility of an extended period of hay feeding, the level of utilization on pastures last year, possible culling and weaning strategies, and a pasture use sequence for multiple pasture rotations. In addition, some farmer and ranchers have the opportunity to use planted annual forages to increase grazing capacity or to provide extra hay. Sourcing seed for this possibility should begin soon.
Some plans place an emphasis on critical or trigger dates. These are dates where one evaluates their total local precipitation up to that date. On May 1, for example, one could determine their total spring precipitation and compare that to long-term averages for their area. If precipitation totals are significantly below the averages, that could trigger a choice of several possible management actions such as an extended period of feeding hay or culling of some livestock. These actions are adjusted to account for varying levels of drought. Other important dates in relation to critical periods for rapid grass growth might include May 15, June 1, June 15, and July 1. For more information on range forage production and interactions with precipitation, please see the publication Grazing Management with Variable Plant Production in the Nebraska Sandhills (https://extensionpublications.unl.edu/assets/pdf/ec3039.pdf).