Agave americana has potential as an agricultural crop to provide biofuel, sweetener, fibers, or other bioproducts. Despite the advantage of requiring little water and the ability to persist on land that would be inhospitable for other crops, A. americana has not yet been commercially cultivated and little is known about how these plants respond to agricultural inputs, mainly water and nitrogen. This study sought to resolve how these plants respond to water and nitrogen and if there may be a potential interactive effect of these inputs. Thirty A. americana plants were assigned to six treatment levels of varied water and nitrogen inputs; physiological and growth responses were measured over the course of one year.
Results/Conclusions
Water and nitrogen impacted A. americana in different ways. Photosynthesis and transpiration rates were mainly impacted by the availability of water, while nitrogen accumulation in the tissues was mainly determined by the availability of nitrogen in soils. Overall, while A. americana can persist with very little input, there may be advantages to irrigating and fertilizing these crops. Additional inputs may increase yields and reduce the amount of time required to reach maturity, but growth responses to nitrogen are not yet completely resolved. Biomass accumulation responds positively to water availability, but it is still unknown if additional nitrogen accumulated in leaf tissue had a significant effect on growth. This study provides some information about how CAM photosynthesis may respond to varied environmental conditions and management strategies.