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Agronomy Journal Abstract - CROPPING SYSTEMS

Productivity and Nutrient Dynamics in Bioenergy Double-Cropping Systems


This article in AJ

  1. Vol. 100 No. 6, p. 1740-1748
    Received: Mar 19, 2008

    * Corresponding author(s): axh161@iastate.edu
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  1. Andrew H. Heggenstaller *a,
  2. Robert P. Anexb,
  3. Matt Liebmana,
  4. David N. Sundberga and
  5. Lance R. Gibsonc
  1. a Dep. of Agronomy, Agronomy Hall, Iowa State Univ., Ames, IA 50011
    b Dep. of Agricultural and Biosystems Engineering, NSRIC Building, Iowa State Univ., Ames, IA 50011
    c Pioneer Hi-Bred International Inc., Johnston, IA 50131


Double-crop systems have the potential to generate additional feedstocks for bioenergy and livestock utilization, and also to reduce NO3–N leaching relative to sole-crop systems. Field studies were conducted near Ames, IA, during 2005–2007 to evaluate productivity and crop and soil nutrient dynamics in three prototypical bioenergy double-crop systems, and in a conventionally managed sole-crop corn system. Double-cropping systems evaluated in the study included fall-seeded forage triticale (X Triticosecale Wittmack), succeeded by one of three summer-adapted crops: corn (Zea mays L.), sorghum-sudangrass [Sorghum bicolor (L.) Moench], or sunn hemp (Crotalaria juncea L.). Total dry matter production by triticale/corn and triticale/sorghum-sudangrass was 25% greater than sole-crop corn, which in turn produced 21% more dry matter than triticale/sunn hemp. Potential ethanol yield was greatest for triticale/corn, which was estimated to have the capacity to produce 1080 L ha−1 more ethanol than sole-crop corn. Crop N uptake was greater in double-crop systems during April-June, greater in the sole-crop corn system during July–August, and greater again in double-crop systems during September–October. Relative to sole-crop corn, potentially leachable soil N was reduced in double-crop systems by 34 and 25%, respectively, in the spring (mid-April) and fall (late October). High nutrient density of biomass coupled with high productivity for triticale/corn and triticale/sorghum systems also resulted in the removal of 83, 41, and 177% more N, P, and K, respectively, compared with sole-crop corn. Sustained removal of large quantities of nutrient-dense biomass from double-cropping systems would necessitate increased fertilization or integration with nutrient recycling mechanisms.

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Copyright © 2008. American Society of AgronomyCopyright © 2008 by the American Society of Agronomy