A review of modeled water use efficiency of highly productive perennial grasses useful for bioenergy

Authors: Kiniry, James; KIM, SUMIN - Oak Ridge Institute For Science And Education (ORISE)

Submitted to: Agronomy
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/27/2020
Publication Date: 3/1/2020
Publication URL: https://handle.nal.usda.gov/10113/6862036
Citation: Kiniry, J.R., Kim, S. 2020. A review of modeled water use efficiency of highly productive perennial grasses useful for bioenergy. Agronomy. 10(3):328-341. https://doi.org/10.3390/agronomy10030328.
DOI: https://doi.org/10.3390/agronomy10030328

Interpretive Summary: Plant productivity obviously is the ultimate product of leaf photosynthesis. As a result, there have been numerous efforts to relate the two. However, often with perennial grasses, plant productivity is more dependent on the number and size of growing leaves and stems than the actual photosynthetic rate, causing linkage between photosynthesis and productivity to be weak or nonexistent. This has led to a different approach, characterizing plant productivity in terms of efficiency of intercepted light to produce biomass, or radiation use efficiency. Likewise, the efficiency of use of water to produce plant biomass, or water use efficiency, has been the object of much interest. Use of a computer simulation model to quantify biomass, using radiation use efficiency, in parallel with a daily water balance simulation, allows effective calculation of water use efficiency. In this project, the process of determining radiation use efficiency with field data is described as well as example values for highly productive perennial grasses useful for feedstock for bioenergy. In addition, values for water use efficiency for these grasses are reported and compared with other perennial grasses and common cultivated crops.

Technical Abstract: Whole plant productivity obviously is the ultimate product of leaf photosynthesis and this has led to numerous efforts to relate the two. However, often with perennial grasses, plant productivity is more sink limited than source limited, causing linkage between photosynthetic rate and productivity to be weak or nonexistent. This has led to a different approach, characterizing plant productivity in terms of efficiency of use intercepted light to produce biomass, or radiation use efficiency. Likewise, the efficiency of use of water to produce plant biomass, or water use efficiency, has been the object of much interest. Use of a simulation model to quantify biomass, using radiation use efficiency, in parallel with a daily water balance simulation, allows effective calculation of water use efficiency. In this project, the process of determining radiation use efficiency with field data is described as well as example values for highly productive perennial grasses useful for feedstock for bioenergy. In addition, values for water use efficiency for these grasses are reported and compared with other perennial grasses and common cultivated crops.