Publication Date
1989
Description
Converting solar energy into biomass is theoretically most energy efficient when species of a high photosynthetic capacity are grown and nitrogen is furnished via symbiotic fixation. Perennial warm season grasses with the C-4 photosynthetic pathway outyield perennial cool season grasses that possess less efficient C-3 pathways. Growing a productive perennial warm season grass in sequence with a winter annual legume should increase yearly capture of solar energy per unit area. The different seasonal growth patterns of the winter legume and the C-4 grass should result in less inter-species competition than occurs in traditional cool season grass-legume combinations. As a result, greater amounts of nitrogen may be fixed for perennial warm season grasses and production increased during the summer growing season. A perennial warm season bunch grass such as eastern gamagrass appears to have the potential of producing in excess of 17 t ha-1 (Faix et al, 1980). Including a legume may reduce or eliminate nitrogen fertilization and therefore significantly increase the energy output to input ratio (Lichtenburg et al, 1980). The objective of this study was to evaluate the energy efficiency of a C-3 and C-4 grass each in combination with selected levels of N fertilization or companion legumes.
Citation
Kaiser, C J., "C-4 Grass with Legumes: An Energy Efficient Biomass System" (2025). IGC Proceedings (1989-2023). 63.
https://uknowledge.uky.edu/igc/1989/session1/63
Included in
Agricultural Science Commons, Agronomy and Crop Sciences Commons, Plant Biology Commons, Plant Pathology Commons, Soil Science Commons, Weed Science Commons
C-4 Grass with Legumes: An Energy Efficient Biomass System
Converting solar energy into biomass is theoretically most energy efficient when species of a high photosynthetic capacity are grown and nitrogen is furnished via symbiotic fixation. Perennial warm season grasses with the C-4 photosynthetic pathway outyield perennial cool season grasses that possess less efficient C-3 pathways. Growing a productive perennial warm season grass in sequence with a winter annual legume should increase yearly capture of solar energy per unit area. The different seasonal growth patterns of the winter legume and the C-4 grass should result in less inter-species competition than occurs in traditional cool season grass-legume combinations. As a result, greater amounts of nitrogen may be fixed for perennial warm season grasses and production increased during the summer growing season. A perennial warm season bunch grass such as eastern gamagrass appears to have the potential of producing in excess of 17 t ha-1 (Faix et al, 1980). Including a legume may reduce or eliminate nitrogen fertilization and therefore significantly increase the energy output to input ratio (Lichtenburg et al, 1980). The objective of this study was to evaluate the energy efficiency of a C-3 and C-4 grass each in combination with selected levels of N fertilization or companion legumes.
