Carbon and Water Dynamics of Tall Bioenergy Grasses in the Southeastern US

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Material Information

Title:
Carbon and Water Dynamics of Tall Bioenergy Grasses in the Southeastern US
Physical Description:
1 online resource (161 p.)
Language:
english
Creator:
Liang, Xi
Publisher:
University of Florida
Place of Publication:
Gainesville, Fla.
Publication Date:

Thesis/Dissertation Information

Degree:
Doctorate ( Ph.D.)
Degree Grantor:
University of Florida
Degree Disciplines:
Agronomy
Committee Chair:
ERICKSON,JOHN E
Committee Co-Chair:
SOLLENBERGER,LYNN E
Committee Members:
ROWLAND,DIANE L
VERMERRIS,WILLEM
SILVEIRA,MARIA LUCIA

Subjects

Subjects / Keywords:
bioenergy -- carbon -- decomposition -- efficiency -- grass -- root -- soil -- water
Agronomy -- Dissertations, Academic -- UF
Genre:
Agronomy thesis, Ph.D.
bibliography   ( marcgt )
theses   ( marcgt )
government publication (state, provincial, terriorial, dependent)   ( marcgt )
born-digital   ( sobekcm )
Electronic Thesis or Dissertation

Notes

Abstract:
This research is focused on better understanding water relations in sorghum, energycane, and elephantgrass for their potential impact on water cycling in the Southeast and on the effect of perennial grass crops on soil carbon storage. The research objectives were 1) to determine water use patterns of elephantgrass and energycane under optimal water inputs and in response to soil drying; 2) to evaluate the effects of deficit irrigation on growth, yield, water use and water use efficiency in two sorghum cultivars differing in root system architecture; and 3) to determine the effect of potential bioenergy perennial grass crop species on root biomass, root decomposition, and soil carbon accumulation over time. In general elephantgrass genotypes exhibited lower breakpoint of stomatal closure compared to energycane genotypes, indicating the stomata of elephantgrass genotypes will not close even at little soil available moisture. Among elephantgrass genotypes, UF-1 tends to keep its stomata open and maintain its photosynthetic assimilation at low soil water, indicating potential for drought tolerance and relatively high biomass under drought stress. Root biomass increased as irrigation decreased, especially in the deep rooted genotype (EH), and root biomass was greater in EH compared to BK7 at low irrigation (25%). Despite differences in RSA, no genotype benefits in grain yield were observed at any irrigation level. In fact, grain yields were negatively related to root biomass across all data. Taken together, optimal grain yield and water use efficiency for both genotypes was between the 50 and 75% irrigation levels. The results of this study support the potential for deep rooting to increase access to soil water, which may increase yield under water deficit, but could also result in a tradeoff between partitioning to root and grain that may reduce its benefit for grain yield. Giant reed had relatively high root biomass production, total carbohydrate and lignin, and high corresponding remaining ratios after incubation. Giant reed root decomposed relatively slowly and tended to last longer in the soil and import more organic carbon to soil. Thus, giant reed was the best species in soil organic matter improvement.
General Note:
In the series University of Florida Digital Collections.
General Note:
Includes vita.
Bibliography:
Includes bibliographical references.
Source of Description:
Description based on online resource; title from PDF title page.
Source of Description:
This bibliographic record is available under the Creative Commons CC0 public domain dedication. The University of Florida Libraries, as creator of this bibliographic record, has waived all rights to it worldwide under copyright law, including all related and neighboring rights, to the extent allowed by law.
Statement of Responsibility:
by Xi Liang.
Thesis:
Thesis (Ph.D.)--University of Florida, 2013.
Local:
Adviser: ERICKSON,JOHN E.
Local:
Co-adviser: SOLLENBERGER,LYNN E.
Electronic Access:
RESTRICTED TO UF STUDENTS, STAFF, FACULTY, AND ON-CAMPUS USE UNTIL 2015-12-31

Record Information

Source Institution:
UFRGP
Rights Management:
Applicable rights reserved.
Classification:
lcc - LD1780 2013
System ID:
UFE0046126:00001