The start of the growing season will be here soon and it is time to finish up grazing and forage plans for the upcoming year. Rangeland and pasture production in 2018 was very good with many areas of the state seeing production 10 to 30% above average. This, of course, was the result of abundant and timely rains during spring into mid-summer. While long-range weather forecasts always have some uncertainty, the Climate Prediction Center currently indicates weak El Nino conditions in the Pacific Ocean.
Historically, this has generally resulted in favorable spring and early summer precipitation. April precipitation and soil moisture are the basis for the initial growth of cool-season pasture grasses, but these species produce the majority of their growth during the month of May. April and May precipitation, as well as temperature, are the two primary factors that might affect spring pasture growth and turn out dates. Warm-season grasses generally initiate growth in May with rapid accumulation of growth in late June and July. Because of the lower water holding capacity of sandy soils, the frequency or length of time between rainfall events can be critical, especially when warm-season grasses put on most of their growth in June and early July.
A relatively new forecasting tool, Grass-Cast, released last year provides information for ranchers on estimated increases or decreases in total plant production based on current weather projections into the growing season. More information on Grass-Cast and other range management tools can be found in a companion article, New Technologies for Range and Pasture Management in this Newsletter.
Grazing plans
Grazing plans should include projected cattle numbers (or stocking rates), turn out dates, and a pasture use sequence for multiple pasture rotations. For those livestock producers that use various types of rotational grazing strategies, it is important to review grazing records from the previous years when planning the rotation sequence for 2019. Consideration should be given to when the time or period of grazing occurred in the previous years and the amount of residual forage in that pasture from the previous year. Plans should adjust the schedule to avoid grazing the same pasture at the same time period in consecutive years.
As we would expect, there is a strong correlation between spring and early summer precipitation and pasture productivity. In a mixed cool- and warm-season grass rangeland, such as the Sandhills, there can be 70% of the season’s total production occurring by July 1. Rainfall in late July or August generally does not contribute to substantial growth for that season; but slows maturation of warm-season grasses and may benefit some fall growth of cool-season species.
Spring is also the time of year when ranchers should review or update their drought plans. A drought plan can have varying levels of detail and complexity and can be customized to fit the specific needs of your operation. Some plans place an emphasis on critical decision 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 April precipitation or the total effective precipitation since the previous fall 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 prior to turn out. These actions should be adjusted to account for varying levels of expected drought. Other important dates for making drought management decisions in relation to critical periods for rapid grass growth might include May 15, June 1, June 15, and July 1. Additional details and worksheets for all the components of a drought plan can be found at ‘Managing Drought Risk on the Ranch.’
Now is also a good time to finalize plans for the planting of spring or summer annual forage crops that might be grazed, hayed, or harvested as silage to replenish feed supplies. This includes selecting the forage crop type, fields that will be planted, identifying seed sources and ordering the seed. Oats, spring triticale and barley are annual cereal grains that can be planted from late March to early April to produce forage that can be grazed beginning in mid to late May or harvested for hay or silage in late June or early July. Growth of these cereal crops is very rapid in late May and early June, requiring good grazing management and the proper stocking rate to efficiently harvest the forage.
Forage peas are a legume that can be mixed in with spring cereals to reduce nitrogen fertilizer needed while maintaining or improving the protein levels of the harvested crop. However, in dryer climates forage pea may not significantly increase forage protein levels compared to an oat monoculture because of limited forage pea growth. When selecting a spring cereal to plant, preference should be given to varieties that have been selected for forage production. Select hooded or awnless varieties of barley if the crop is going to be harvested as hay. The quality of the forage produced from spring cereals will depend upon the stage of maturity at harvest. As maturity increases, quality declines rapidly. The optimum compromise between quality and yield generally occurs shortly after boot to early heading stages. Yield in terms of dry matter produced per acre generally increases 10 percent to 20 percent from the boot to early heading stages.
The primary warm-season or summer annual forages would include sudangrass, forage sorghum, sorghum-sudangrass hybrids, pearl and foxtail millet. As warm-season species, soil temperatures at planting should consistently be at the 60 to 65 degree Fahrenheit level which is usually achieved by late May. These warm-season annuals could also be planted anytime up to early August and still produce forage, but greater amounts will be realized with earlier planting dates. Additional information regarding the planning of annual forage systems can be found on the Planning Annual Forage Systems Webinar.
The NebGuide, “Utilizing Annual Forages with Limited Irrigation for Beef Cattle During and Following Drought”contains information on utilizing annual forages during and after drought.
