A dry fall and winter has most of Nebraska starting spring in a moisture deficit. As we head into the growing season, assessing pasture conditions at the correct time is critical to successful planning. How can you use trigger dates to inform your drought planning this year?
One of the main factors driving annual forage production in Nebraska’s grazing lands is available moisture. Both cool- and warm-season grasses in the state rely heavily on spring and early summer precipitation at a time when the plant is rapidly growing. This period of rapid growth varies by species and is driven by air temperature, day length, and soil moisture. Once optimal conditions have passed, getting significant growth even if it does rain is difficult.
With this in mind, we can set up some trigger dates to assess moisture levels and pasture conditions, informing the implementation of a drought management plan.
• April 15 to May 10: smooth bromegrass pastures with below average precipitation, annual production may be reduced 25% to 50%.
• May 20 to June 10: Assess earlier precipitation levels. If March-May precipitation was 50% to 75% of the long-term average, reduce stocking rates 30-40% or more depending upon grass species and plant health.
• June 15 to June 30: Approximately 75% to 90% of grass growth on cool-season dominated range sites and 50% of grass growth on warm-season dominated range sites will have happened. Rainfall after late June results in limited benefit to cool-season grass production.
• July 15: Precipitation after this date will have limited benefit to warm-season tallgrass production but can still result in some forage growth from shortgrass warm-season species such as buffalograss and blue grama.
Knowing when to pull the trigger on drought plans is not an easy decision, but it can mean the difference between managing with conditions or scrambling to catch up. This year, use trigger dates for your operation to successfully implement drought mitigation strategies.
