Planning for Spring Annual Forages
While we are still early in the new year, it is time to start thinking about any spring annual forages that we might plant. Part of the process may be anticipating a need for extra feed or booking seed early for possible discounts.
For spring or cool-season annual forages, the planting period is typically late March to early April, or when soil temperatures are in the 42-to-45-degree range. Oats is probably the most common cool-season annual forage planted in Nebraska. However, spring triticale or spring barley are two other small grain options that have been found to perform similarly to oats in terms of forage yield and quality.
Also similar is the number of days until ready to begin grazing or hay, so the different species could be mixed if desired. One could look at seed cost of the different species before making a decision. With the early spring planting date of the cool-season annuals, grazing can typically begin around the third or fourth week of May and last into early July. Haying usually take place around the third week of June.
If grazing is a primary goal, Italian ryegrass could be included in a mix with the cereal grains and this will result in a longer grazing period. Field peas are another species that could be included to enhance forage quality and provide some nitrogen fixation.
Remember to consider the herbicides that may have been used on a field the previous year. Some herbicides may have long residuals that could hinder establishment even into this spring.
Winter Cold and Insect Mortality
With forecasted bitterly cold temperatures across Nebraska, producers may be wondering if overwintering insect pests could be killed and their populations reduced. Although we could see temperatures in single or negative digits with wind chills reaching several degrees below zero, insects have adapted to survive winter’s chill.
Many of our most significant pests, like western bean cutworm and western corn rootworm, spend the winter below the soil surface. While soil temperature is dependent on many factors, it generally does not fluctuate significantly, even during extreme cold snaps. Soil that is covered by crop residue or snow will be further protected from bitter air temperatures. This means that the insects overwintering belowground are protected as well.
Insects that overwinter in more exposed areas have additional cold adaptations. For example, soybean aphids overwinter as eggs and supercool to temperatures as low as -29°F, while European corn borer larvae can produce glycerol, a substance which acts as a biological antifreeze.
Additionally, keep in mind that not all our insect pests overwinter in Nebraska. Several species, including the fall armyworm, black cutworm and corn earworm, spend the winter in warmer climates and migrate to Nebraska during the growing season.
Even though insect pest populations will undoubtedly survive this period of extreme cold, remember that beneficial insects like parasitoids and natural predators will survive too.