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ARS Home » Plains Area » El Reno, Oklahoma » Oklahoma and Central Plains Agricultural Research Center » Livestock, Forage and Pasture Management Research Unit » Research » Publications at this Location » Publication #377639
Research Project: Sustaining Southern Plains Landscapes through Improved Plant Genetics and Sound Forage-Livestock Production Systems

Location: Livestock, Forage and Pasture Management Research Unit

Title: Effect of nitrogen fertilization on biomass yield of sand bluestem (Androgpogon hallii Hack)

Author
item Springer, Timothy

Submitted to: BioEnergy Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/6/2020
Publication Date: 11/20/2020
Citation: Springer, T.L. 2020. Effect of nitrogen fertilization on biomass yield of sand bluestem (Androgpogon hallii Hack). BioEnergy Research. https://doi.org/10.1007/s12155-020-10220-w.
DOI: https://doi.org/10.1007/s12155-020-10220-w

Interpretive Summary: Sand bluestem is one of the most productive native grasses on sandy soils in the Great Plains making it a good candidate for use as renewable energy; however, very little information is available for its biomass production under high nitrogen fertilization rates. In a six-year study, that included two drought years, plots of sand bluestem were fertilized annually at four rates with urea nitrogen (0, 35, 70, and 105 pounds N/acre) to determine the effects of fertilization on biomass yield and nitrogen use efficiency (the pounds of harvested biomass per pound of applied N). Unfertilized plots of sand bluestem averaged 1.3 tons/acre of biomass compared with 3.7 tons/acre of biomass for plots fertilized with 105 pounds N/acre. Low N fertilization rates produced the greatest nitrogen use efficiency. In addition, drought significantly impacted the biomass yield of sand bluestem; however, at high fertilization rates and certain environmental conditions, sand bluestem can produce biomass yields in excess of 6 tons/acre. To consistently produce high yields supplemental irrigation would be needed; however, producers should consider the economics of irrigation as it relates to the production of sand bluestem biomass.

Technical Abstract: Sand bluestem (Andropogon hallii Hack.) is one of the most productive native grasses on sandy soils in the Great Plains making it a good candidate for a multispecies approach to biomass production. The objectives of this study were to evaluate the biomass yield, nitrogen use efficiency (NUE), and apparent N fertilizer recovery of sand bluestem grown in a monoculture. Plots were fertilized annually with N at the rates of 0, 40, 80, and 120 kg/ha. Biomass yield varied with N rate × year interactions (P < 0.01). Averaged over six years, which included two drought years, biomass yield ranged from 3.0 to 8.3 ± 0.3 Mg/ha. Nitrogen use efficiency and crop N recovery efficiency varied with year and N rate (P < 0.01). Nitrogen use efficiency was 69, 88, and 154 kg/kg of applied N for the 120, 80, and 40 kg N/ha rate, respectively. Apparent fertilizer N recovery varied from 0.27 to 0.40 kg/kg of applied N among fertilization treatments with the greatest recovery from the 40 kg N/ha rate. Under certain environmental conditions, monocultures of sand bluestem can produce biomass yields in excess of 10 Mg/ha when fertilized at rates = 80 kg N/ha. To consistently produce these yields supplemental irrigation would need to be used; however, the economics of irrigation still needs to be researched to determine the optimum irrigation schedules and amounts of water to apply as well as nutrient management with irrigation.