|SARAH, DAVIS - Ohio University|
|KUZMICK, EMILY - Ohio University|
|NIECHAYEV, NICHOLAS - Ohio University|
|Hunsaker, Douglas - Doug|
Submitted to: Global Change Biology Bioenergy
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/9/2015
Publication Date: 1/25/2017
Publication URL: http://handle.nal.usda.gov/10113/5700701
Citation: Sarah, D.C., Kuzmick, E.R., Niechayev, N., Hunsaker, D.J. 2017. Productivity and water use efficiency of Agave americana in the first field trial as bioenergy feedstock on arid lands. Global Change Biology Bioenergy. 9:314-325.
Interpretive Summary: Agave plants are high-yielding plants that are recognized as a potential bioenergy crop for dry regions of the world. This research is the first known field study to determine if agave can be grown productively as a bioenergy crop in desert regions of the Southwestern US. The three-year agave field experiment was conducted in Maricopa, Arizona, and included four levels of irrigation, from 4 inches to 24 inches of irrigation annually. It was found that the highest yield was obtained with 12 inches of irrigation applied per season. In terms of bioenergy production, the agave yield was comparable to corn grain yields. The findings suggest that agave could become a bioenergy feedstock in semi-arid and arid US regions and has very low irrigation water requirements compared to the traditional crops grown in the regions. This research will be of interest to farmers in semi-arid and arid regions, water management agencies, and the biofuel industry.
Technical Abstract: Agave species are known as high-yielding crassulacean acid metabolism (CAM) plants, some of which have been grown commercially in the past and are recognized as potential bioenergy species for dry regions of the world. This study is the first field trial of Agave species for bioenergy in the United States, and was established at the Maricopa Agricultural Center in Maricopa, Arizona to compare the production of the native Agave americana with the production of two Agave species that are produced commercially in Mexico for tequila and fiber. The field trial included four experimental irrigation levels to test the response of biomass production to water inputs. After three years, the optimum annual production of healthy A. americana plants was 4 - 9.3 Mg ha-1 y-1 with 530 mm of annual water inputs, including both rainfall and irrigation. Yields in the most arid conditions tested (300 mm y-1 water input) were 2 - 4 Mg ha-1 y-1. The commercial species (Agave tequilana and Agave fourcroydes) were severely damaged by cold in the first winter, and produced only a small fraction of the biomass observed in A. americana. Physiological differences in A. americana plants across irrigation treatments were most evident in the warmest season, with nocturnal gas exchange beginning up to three hours earlier in the well-watered plots, but water use efficiency declined in the highest irrigation treatment (780 mm y-1 water input). Yields were lower than previous projections for Agave species, but A. americana has potential as an environmentally sustainable bioenergy crop that could replace conventional crops in the southwestern US and have substantially reduced irrigation requirements, with possibly no irrigation required after establishment. Challenges for pest management and harvesting must still be addressed to achieve an economically efficient bioenergy production system.