Feed and fuel: the dual-purpose advantage of an industrial sweetpotato

J Sci Food Agric. 2017 Mar;97(5):1567-1575. doi: 10.1002/jsfa.7902. Epub 2016 Aug 11.

Abstract

Background: Sustainable agricultural systems must support nutritional requirements, meet the energy demands of a growing population, preserve environmental resources and mitigate climate change. The sweetpotato (Ipomoea batatas L.) is a high-yielding crop that requires minimal fertilization and irrigation, and the CX-1 industrial cultivar offers superior potential for feed and fuel.

Results: CX-1 had the highest agronomic fresh vine yield (51.5 t ha-1 ), averaged over two cropping seasons, compared with Hernandez (33.7) and Beauregard (21.8) varieties. CX-1 vines were more nutritional than the table varieties, specifically in regard to relative feed value (205), water-soluble carbohydrates (171 g kg-1 dry matter (DM)), total digestible nutrients (643 g kg-1 DM), metabolizable energy (10.2 MJ kg-1 DM) and organic matter digestibility. Their lower fiber and lignin concentrations contributed to their freshness and digestibility throughout maturity. Significantly higher iron concentrations make the CX-1 vines a valuable, low-fat iron supplement for animal feed. The CX-1 roots also showed the highest bioethanol potential (82.3 g ethanol kg-1 fresh root) compared to Hernandez (64.5) and Beauregard (48.1).

Conclusion: The CX-1 industrial sweetpotato is an ideal dual-purpose crop for tropical/subtropical climates that can be utilized as a non-grain-based feedstock for bioethanol production while contributing a valuable, high-yielding nutritional supplement for animal feed. © 2016 Society of Chemical Industry.

Keywords: animal feed; bioethanol; industrial cultivar; roots; sweetpotato; vines.

MeSH terms

  • Animal Feed / analysis*
  • Biofuels*
  • Dietary Fiber / analysis
  • Dietary Supplements / analysis
  • Ipomoea batatas / chemistry*
  • Ipomoea batatas / growth & development
  • Iron
  • Nutritive Value
  • Plant Roots / chemistry
  • Plant Stems / chemistry

Substances

  • Biofuels
  • Dietary Fiber
  • Iron