KSU AGRONOMY eUpdate – Fall forage yield is an important aspect of dual-purpose wheat production. In this system, wheat is typically sown earlier than for grain-only production, at higher seeding rates, and with additional nitrogen fertilizer to maximize forage production.
The weather experienced during the fall is crucial in determining the average level of forage yield, with warm and moist weather typically resulting in greater forage yield than cool and dry weather conditions. Management practices that maximize forage yield include early sowing, higher seeding rates, placement of in-furrow phosphorus fertilizer with the seed, and fall nitrogen fertilization.
While the weather is typically the largest factor in determining fall forage production, followed by management, there are also differences among wheat varieties in forage production potential. Thus, every year the K-State Wheat Production Group compares the forage yield of several commonly grown wheat varieties and upcoming lines. This test is usually performed in the South Central Experimental Field near Hutchinson, Kansas (Figure 1), and the forage sampling occurs sometime during December (Table 1).
Figure 1. Dual-purpose wheat trial near Hutchinson, KS. The trial was sown on September 18, 2019, with 50 lbs DAP/acre applied in furrow, and 90 lbs N/acre broadcast incorporated prior to sowing. Photo by Romulo Lollato, K-State Research and Extension.
Table 1. Fall forage yield of wheat varieties sown under dual-purpose system near Hutchinson, KS. Forage biomass was collected on 20 December 2019. Data is shown in pounds of dry matter per acre (lbs DM/ac). Tukey’s honest least significant difference (HSD) is shown, with highest yielding group highlighted in bold. Varieties are ordered from highest to lowest forage yield.
|Variety||Forage dry matter (12/20/19)|
|——- lbs/ac ——-|
|Doublestop CL Plus||1095|
|KS Western Star||809|
|SY Achieve CL2||438|
There was a significant difference in fall forage yield among the 28 wheat varieties tested in the 2019-2020 experiment (Table 1). Forage yield ranged from 438 to 1,888 pounds of dry matter per acre, with Gallagher, WB4303, Rockstar, WB4269, Paradise, Smith’s Gold, and WB4792 yielding similarly in the top forage group. Likewise, all varieties listed at TAM 205 and below had similar forage yield and did not differ statistically.
Impact of weather conditions on 2019 fall forage production
While it is common for a large range in forage yields to exist among wheat varieties (for example, in 2018-19 our forage measurements ranged from 1,327 to 2,700 lbs/acre), the large range in forage values experienced in the 2019-20 partially reflect the dry conditions experienced during the fall. Plots were planted on extremely dry soils on September 18, and it was not until the October 1-5 interval that ~0.9 inches of precipitation was received. This resulted in a somewhat uneven stand establishment, which could partially explain these results. Additionally, after October 5, the next rainfall event was not until the November 20-29 interval, when about 0.45 inches were received in total of six smaller events. The dry conditions experienced at planting and during the entire fall, coupled with below-average fall temperatures, did not allow for much forage biomass production and increased the plot-to-plot variability in the measurements.
Stay tuned for First Hollow Stem reports
Another important aspect of dual-purpose wheat production is how long each variety can be grazed in the spring. This is measured as the date for first hollow stem. Wheat varieties can differ by as much as 20-30 days in achieving first hollow stem in the spring. The Wheat Production Group at K-State uses this very same trial to measured first hollow stem during late February and early March, so keep tuned the eUpdate as winter progresses toward spring.
Romulo Lollato, Extension Wheat and Forages Specialist
Kavan Mark, Research Assistant